Competitive advantage and core competency are the unique capabilities and assets of an organization to provide valuable products or services to customers, thus giving the organization a better competitive position in the market than its competitors. In addition, how to create a competitive advantage is also one of the main objectives of business strategy. Therefore, this study focuses on understanding the decisive factors in regional revitalization and the relationship between business strategy, strategic alliance, and alliance performance through small and medium enterprises (SMEs) in Taiwan. This study selected a sample of 220 SMEs in Taiwan that had participated in the SME regional revitalization counseling program. The results showed that competitive advantage, core competency and strategic alliance partner selection had significant effects on alliance performance. In addition, core competency had an indirect effect on alliance performance through strategic alliance partner selection. However, competitive advantage did not have a significant effect on strategic alliance partner selection. Finally, this study proposes management implications and practical suggestions for SMEs’ competitive advantage, core competency, and alliance performance. In today’s intensely competitive business environments, it is vital for enterprises to adopt swift actions that guarantee their financial security and market position. Many enterprises are constantly employing measures to acquire sustainable competitive advantages. They need to rely more on their internal advantages to provide more customer value and differentiate and expand their products. In other words, an enterprise’s performance is dependent on their core competence. Thus, regional revitalization strategies should shift from offering competitive products or services to focusing on an enterprise’s core competence. Core competence is essential in strategy formulation as it is an important source for acquiring overall competence. Because a wide range of employment opportunities is concomitant with developments in the industrial and commercial sectors, a large proportion of youths and employed individuals live in urban areas, which results in widespread urbanization in many countries. To redress the imbalance between urban and rural development derived from overpopulation in metropolitan areas, Taiwan drew lessons from Japan’s experience of promoting regional revitalization, with the hopes of tapping into unique resources in local areas and creating distinct core values in these areas. In 2016, Taiwan initiated the Regional Revitalization by Design program by incorporating creativity, innovation, and entrepreneurship mechanisms as new drivers for developments in regional industries.It is important for regional revitalization organizations to leverage their distinct skillsets (core competencies) to distinguish themselves from their competitors. An organization with core competencies is significantly superior to their industry rivals because their core competencies function as a basis for adding value to their products . Core coThe salience of the concept of core competency has prompted researchers to propose various core competence models to help sustain a company’s competitive advantage . The stuSummarizing the arguments above, core competency refers to an organization’s capability to modify, evolve, or combine technologies or knowledge throughout the process of regional revitalization so as to surpass their competitors. Additionally, a company’s core competency is not only their main business strategy but also affects their competitive advantage and business performance. In today’s knowledge-based economy, companies face major changes in competitive environments, such as quantum leaps in technological innovations as well as unpredictable market changes. When companies perceive that they are unable to adapt to the rapid changes in their industry’s environments because they lack the resources and capabilities for independent development, they must consider establishing partnerships by using their connections in order to expand their competitive advantages in fiercely competitive scenarios, acquire necessary organizational resources and assets, and strengthen their competitive advantage and profit margin . DruckerMany companies today embrace agile methodologies to sustain their competitive advantage. Thus, in response to this new competitive challenge, many companies have begun to enhance their core competencies by using different strategic activities or tools to enhance their competitiveness. To a certain degree, competitive advantage is sourced from rare, valuable, and sustainable resources and is shaped by a company’s competitiveness and capabilities . CompaniSome young companies emphasize technology as their source of competitive advantage, while others opt to use other measures to pursue similar goals. For example, product or service differentiation can be realized through various means, such as technology, design, or workmanship . BecauseThis study suggests that competitive advantage is a company’s ability to leverage its distinct capabilities and resources and provide customers with valuable products or services, thus allowing it to gain a more favorable competitive position than its competitors in the regional revitalization market. The creation of a company’s competitive advantage is also one of the primary objectives of a business strategy as it affects an organization’s business performance. Following the decision to join a strategic alliance, the next critical decision for a company is to select suitable partners . PreviouPrevious studies have explored the topic of partner selection in a strategic alliance , mostly The most important factor in a strategic alliance is the selection of suitable partners, as this enables a holding company to achieve success in dynamic business environments. It is impossible even for high-level alliance management to overcome the preliminary screening of unsuitable partners as well as work selection . Even thHorizontal and vertical integrations have blurred the line of industry boundaries. Amidst the backdrop of the globalized division of labor, as well as cooperative environments, strategic alliances have gradually become a mainstream organizational strategy . The goaBased on the aforementioned background and motivations, the decisive factors of an SME’s success in the regional tourism revitalization field are important for understanding the relationships between business strategies, strategic alliances, and alliance performances. For instance, the means to establish a company’s core competency and competitive advantage, as well as partner selection, are important for enhancing the performance of strategic alliances of SMEs in the field of regional tourism revitalization. This study centers on the relationships between core competency, competitive advantage, and strategic alliance partner selection, as well as their influences on alliance performance. The main objective of this study is to understand the extent to which core competency, competitive advantage, and partner selection affect the performance of strategic alliances comprising SMEs participating in regional tourism revitalization, as well as the relationships between these variables.Additionally, in environmental management practice, companies can improve their competitive advantage through innovation (such as developing green products or processes) or positively affect their competitive performance through the mediating effects of images and media . AdditioThe concept of core competency has evolved from a resource-based perspective. It is also known as organizational capability, distinct capability, or dynamic capability. Core competency has been studied extensively . CompaniMeanwhile, core competency is also a set of advantages, experiences, knowledge, and capabilities that a company leverages to distinguish itself from its competitors. Employees should instill these qualities to achieve task objectives. Core competency is, therefore, a collection of resources, knowledge, skills, information, and values that not only includes the integration and application of existing knowledge, resources, and skills, but also involves having an acute awareness of market demands, accurate assurance of market opportunities, and providing timely customer satisfaction and valuable services .The high level of unpredictability in customer demands and market demands, in addition to increasingly intense global competition as well as environmental uncertainties, has impacted companies tremendously. Therefore, many companies have begun to encourage strategic partnership relations and alliances. On a global scale, business partnerships and alliances are constantly growing . StrategStrategic alliances are typically defined as voluntary cooperative arrangements between companies in which they exchange, share, or jointly develop capital, techniques, or company-specific resources . TraditiPartner selection is an important determinant of an alliance’s success in the process of supply chain management, especially in long-term relations. The study by Alliance performance is a subjective measure of an alliance’s cooperation outcomes. It reflects the degree to which preset objectives or planned periodic objectives are achieved, as well as alliance partners’ expectations for the future. Strategic alliances contribute to a company’s competitive advantage by validating its performance outcomes . ParticiAccording to A study by H1: Competitive advantage has a significant and positive effect on strategic alliance partner selection.H2: Core competency has a significant and positive effect on strategic alliance partner selection.Following its increasing popularity and prominence in recent years, the influence of alliance networks on the overall performance of a company has become a popular topic for researchers and businesses . SuitablThe study by H3: Strategic alliance partner selection has a significant and positive effect on alliance performance.H4: Competitive advantage has a significant and positive effect on alliance performance.Previous studies have identified a relationship between competitive advantage and organizational performance . Core coH5: Core competency has a significant and positive effect on alliance performance.Core competency consists of shared vision, cooperation, and empowerment. The 23-item core competency scale in this study was adapted from the scale developed by Booming industrial and commercial developments in Taiwan have created numerous job opportunities. A majority of young employed workers live in urban areas, which amplifies urbanization in Taiwan. This study examines the relationships between the core competency, competitive advantage, and alliance performance of SMEs participating in regional tourism revitalization. The sample size consists of 233 companies that have participated in the Small Business for Township Revitalization program. Two hundred and forty-five questionnaires were administered, eight of which were removed for having incomplete or inappropriate responses. There were 220 valid responses in total, indicating an effective recovery rate of 96.06%. To test the proposed research model see  and analvia heterotrait-monotrait ratio of correlations (HTMT). All HTMT ratio values between the constructs are below the conservative threshold of 0.85 . Thus, H1 is not supported. Second, the path coefficient of the effect of core competency on partner selection is 0.658, with a standard deviation of 0.078 . H2 is, therefore, supported by the significant level testing. Third, the path coefficient of the effect of partner selection on alliance performance is 0.376 . H3 is therefore supported. Fourth, the path coefficient of the effect of competitive advantage on alliance performance is 0.249 . H4 is, therefore, supported. Fifth, the path coefficient of the effect of core competency on alliance performance is 0.226 . Therefore, H5 is supported.Inner model specifically elucidates the relationships between constructs and can be used to validate the hypotheses in the study framework. First, the path coefficient of the effect of competitive advantage on strategic alliance partner selection is 0.050 (R2 statistic as an indicator of the explanatory power of a model (R2> 0.67, R2> 0.33, and R2> 0.19 indicates high, moderate, and low explanatory power, respectively (R2 of partner selection and alliance performance is 0.486 and 0.562, respectively. This suggests that the model has a decent explanatory power, as shown in Furthermore, this study used the  a model . Endogenectively . The resThis section concludes the statistical analysis findings in the previous section and proposes several recommendations. Firstly, we shall summarize the findings of this study. Next, we will outline the management implications and practical recommendations for SMEs participating in township tourism revitalization to enhance their core competency, competitive advantage, partner selection, and alliance performance. Lastly, we shall describe the limitations of this study and offer several recommendations for future research.First, the path analysis results showed that competitive advantage did not have a significant effect on partner selection. This implies that there is no significant correlation between competitive advantage and partner selection among SMEs participating in township revitalization. The hypothesis is not supported. A possible reason is that competitive advantage refers to a company’s existing strategies that cannot be replicated by their potential competitors. Companies with strong competitive advantage are less likely to select companies with weak competitive advantage as their partners. On the other hand, a company with weak competitive advantage is less likely to be selected as a partner by other companies with strong competitive advantage. As a result, there is no significant correlation between competitive advantage and partner selection.Next, the path analysis results showed that core competency has a significant effect on partner selection. This indicates that there is a significant correlation between core competency and partner selection among SMEs participating in regional revitalization. The hypothesis is supported. Core competencies in this study include three internal sub-dimensions of a company, i.e., shared vision, cooperation, and empowerment. During partner selection, it is necessary for companies to consider their shared visions, methods of cooperation, degrees of empowerment, as well as similarities and compatibility with alliance partners. This results in a significant correlation between core competency and partner selection among SMEs participating in township revitalization. This finding validates a previous study, which found that core competency is associated with strategic alliance formation .Third, the path analysis results showed that partner selection has a significant effect on alliance performance. This indicates that there is a significant correlation between partner selection and alliance performance among SMEs participating in township revitalization. The hypothesis is supported. Selecting the correct partners enables companies to enjoy synergistic effects that augment their alliance performance. In contrast, selecting unsuitable partners not only encumbers alliance performance but may also lead to personal loss. The success of a strategic alliance hinges on the selection of suitable partners. Therefore, there is a significant correlation between partner selection and alliance performance among SMEs participating in township revitalization, and this finding is in line with a previous study, which found that core competency is associated with strategic alliance and competitive advantage formation .Fourth, the path analysis results showed that competitive advantage has a significant effect on alliance performance. This indicates that there is a significant correlation between competitive advantage and alliance performance among SMEs participating in township revitalization. The hypothesis is supported. Companies with strong competitive advantage have excellent sensitivity and responsiveness, and are capable of improving their performance. In a similar vein, allying with companies with stronger competitive advantage naturally generates a better alliance performance. Thus, there is a significant correlation between competitive advantage and alliance performance among SMEs participating in township revitalization. This finding is consistent with previous studies, which found that core competency is associated with alliance performance .Fifth, the path analysis results showed that core competency has a significant effect on alliance performance. This indicates that there is a significant correlation between core competency and alliance performance among SMEs participating in township revitalization. The hypothesis is supported. Core competencies in this study include three sub-dimensions intrinsic to a company, i.e., shared vision, cooperation, and empowerment. Company alliances with stronger core competencies will definitely perform better than those with weaker core competencies. Therefore, there is a significant correlation between core competency and alliance performance among SMEs participating in township revitalization. This finding is consistent with a previous study, which found that core competency is associated with alliance performance .Although this study has both theoretical and practical implications, there are also limitations that need to be improved in subsequent studies. First, the results of this study may be limited in inference because the level of understanding of the survey respondents in the government-subsidized enterprises may be different from the actual level of understanding of the contents of the completed questionnaire. In addition, the respondents of this study may be subject to differences in industry and employment environment. Therefore, it is suggested that future studies may conduct in-depth discussions on the causes and consequences of industrial alliances through different industrial categories. In addition, future studies may conduct in-depth focus group interviews to better understand the possible factors affecting the performance of business alliances.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.CL and CW: conceptualization and methodology. CL: investigation and formal analysis. CL, CW, and DJ: writing—original draft preparation and writing—review and editing. DJ: supervision. All authors: contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Yet, estimating changes in the activity of ice-dam failures through time remains controversial because of inconsistent regional flood databases. Here, by collating 1,569 ice-dam failures in six major mountain regions, we systematically assess trends in peak discharge, volume, annual timing and source elevation between 1900 and 2021. We show that extreme peak flows and volumes (10 per cent highest) have declined by about an order of magnitude over this period in five of the six regions, whereas median flood discharges have fallen less or have remained unchanged. Ice-dam floods worldwide today originate at higher elevations and happen about six weeks earlier in the year than in 1900. Individual ice-dammed lakes with repeated outbursts show similar negative trends in magnitude and earlier occurrence, although with only moderate correlation to glacier thinning8. We anticipate that ice dams will continue to fail in the near future, even as glaciers thin and recede. Yet widespread deglaciation, projected for nearly all regions by the end of the twenty-first century9, may bring most outburst activity to a halt.Episodic failures of ice-dammed lakes have produced some of the largest floods in history, with disastrous consequences for communities in high mountains An assessment of ice-dam failures in six mountain regions shows that extreme peak flows and volumes have declined sharply since 1900, and that ice-dam floods today originate at higher elevations and earlier in the year. These ice dams temporarily and periodically impound rainfall and meltwater that can be released abruptly following dam flotation, subglacial tunnel enlargement or mechanical collapse10. Such glacier lake outburst floods (GLOFs) initiate hazard cascades with numerous impacts downstream. Historic ice-dammed GLOFs have travelled hundreds of kilometres, entraining sediment along their runout paths; widening river channels by bank erosion; triggering landslides from undercut and destabilized hillslopes; and covering valley floors with metre-thick sheets of sediment, ice and woody debris14. Extreme GLOF discharges can raise local river levels by several metres, increasing bed shear stresses and stream power values sufficiently to incise bedrock15. Floods from the largest lake outbursts can last for several days and destroy local flood control systems16. In many mountain regions, settlements, tourism, forestry and mining advanced into high mountain valleys during the twentieth century17 and thus closer to the source areas of GLOFs. As a consequence, ice-dam failures have caused many hundreds of fatalities, damaged infrastructure and farmland worth hundreds of millions of dollars, and disrupted transportation and communication routes1.One of the major hazards caused by ongoing glacier retreat are sudden floods resulting from the failure of unstable glacier dams18. Thus, in the future, ice dams might store an increasing amount of meltwater, causing larger floods if they fail. However, the few detailed case studies of ice-dammed lakes, particularly in Iceland and northwest North America19, suggest the opposite. There, individual ice-dammed lakes fill and empty repeatedly, releasing gradually smaller flood volumes over time. The edges of glacier dams might begin to float on the adjacent lake once a critical lake level is reached, suggesting that a gradually thinning glacier dam requires a lower threshold to initiate subglacial drainage21. Within this cycle, the timing of GLOFs, that is, the day of the year when a lake begins to drain, is likely to shift, given that thinner dams may require a shorter period of time to refill to their maximum storage capacity22. This cycle of GLOFs from a given lake may end when the ice dam has decayed to the point where it can no longer impound water21. Yet, new cycles of GLOFs might originate from higher elevations with ongoing exposure of ice-free areas at glacier margins23.Despite the hazard posed by ice-dammed lakes, temporal trends in the magnitude and timing of their failures remain poorly understood in most mountain regions. We attribute the limited knowledge of contemporary GLOF activity to the largely unsystematic and regionally inconsistent record of GLOFs. How strongly, or whether at all, regional GLOF activity responds to accelerating glacier melt therefore remains an open question. Melting glacier margins create new space for ice-dammed lakes to form and growQp and flood volume V0. Using Bayesian hierarchical quantile regression models, we estimated global and regional trends in reported median and extreme discharges, defined as GLOFs exceeding the 50th and 90th percentiles of the conditional distributions of reported Qp and V0. We also used regression models to assess changes in the regional timing and the median source elevation of ice-dam failures , and in median V0 in 31% (8 of 26) of all cases. Only one lake had a credible increase in Qp or V0 over the GLOF cycle , a period with greater research activity, yields broader posterior trend estimates as fewer data points enter the model  may explain the only increase in the 10% highest records of Qp in the European Alps since 1990  by global standards27. Regional trends in extreme V0 since 1990 mirror those of extreme Qp, and are negative in five of the six regions. Except for a negative trend in High Mountain Asia, all regional trends in median V0 remain unchanged. By explicitly drawing on stratified subsets of the data, we conclude that regional trends in GLOF size over the recent shorter time interval with probably better documentation hardly deviate from the long-term trends. The recent decrease in extremes is striking because these arguably represent the best documented events with large values of Qp and V0, making a potential increase in extreme GLOFs with time very unlikely.All regions had more abundant reported GLOFs since 1990 compared with earlier decades  ice-dammed lakes for which there is a documented day of the year (doy) burst out earlier in the year on average; in 30% of these cases, trends are credibly negative  of the 101 glaciers with two or more failures stopped releasing GLOFs before 2000. Occasionally, human intervention interrupts the natural GLOF cycle, especially in cases where outbursts have repeatedly damaged infrastructure. In the European Alps and in Scandinavia, engineered structures such as drainage tunnels through bedrock or glacier ice stopped the recurrent outbursts of at least six ice-dammed lakes29.Most GLOFs happen in summer, and winter remains largely free of GLOFs  Fig. . In cont31. GLOFs in the European Alps had no credible change in elevation during our study period, although many large dams formed at lower elevations before 1900, when glaciers descended down to major valleys2. These dams disappeared with warming and glacier retreat after the mid-nineteenth century2. In contrast, High Mountain Asia has had more than 100 valley-blocking glacier advances to lower elevations in the past three decades32, explaining the unchanged elevation trend of ice-dam failures in that region. In most regions, outbursts emerged from lakes that were tens to many hundreds of metres lower in elevation than today , for which we could obtain the cumulative elevation change of the ice dam, maximum lake areas before outbursts and reported GLOF magnitudes (V0 or Qp) between 2000 and 2019  may indicate recurrent opening and closing of the same subglacial tunnel system that allows the floods to attain high peak flows despite decreases in glacier thickness22. Floating ice can further exert high pressures on the underlying water in lakes, maintaining high Qp and V0 independent of glacier thinning that reduces the basin’s storage capacity36. In contrast, high variances or abrupt changes in the trends may indicate shifts between drainage regimes, for example due to failure of ice buttresses at the point of inflow into the glacier19. Ice motion during an outburst can also close subglacial tunnels before the lake has emptied completely34. Some lakes such as Lago Cachet , annals and reports published by local and regional authorities (18%), written communications in emails with eyewitnesses and experts (9%), and newspapers and internet resources such as video footage and posts on social media platforms . Secondary sources  include second-hand information derived from reviews and summaries of previous publications (19%) and entries in databases with no direct access to the primary source (17%). Half of all sources report only a single event, whereas a few studies include information on dozens of GLOFs. For example, ref. 60 identified more than 100 outbursts from lakes impounded by Kennicott Glacier during the twentieth century by studying stream gauge data and historical aerial photographs. Still, decades may elapse between the date of a GLOF and the reporting, especially where researchers reprocessed and reanalysed historical data  forced farmers to abandon their homes in the mid-1960s16. It is only since the 1970s that research activity on GLOFs has become more consistent24: 63% GLOFs in our databases were first documented in that period  and the name of the burst glacier lake. We extracted the surface elevation of each lake centroid from the Advanced Land Observing Satellite (ALOS) V3.2 digital elevation model (DEM)64. We collected the reported flood volume , peak discharge  and timing . Finally, we documented any impacts, damage, and losses for events in our database.In collecting historic GLOFs, we only considered cases with either a documented date (at least the year of occurrence) or a time interval of failure, centroidal coordinates of the lake and at least one reference. For each GLOF, we documented the mountain range, the country from which the flood originated, the name of the parent glacier , have higher spatial resolution and thus capture GLOF features in greater detail. Ice-dammed lakes decrease in size, or even empty entirely, during GLOFs, exposing either partly or fully the lake floor, which is often covered with stranded icebergs  or local  groups. Bayesian models form a compromise between the likelihood of observing the data under the assumption of specific model parameters and prior knowledge about these parameters. We encode our uncertainty in this prior knowledge before obtaining a posterior distribution for all parameters conditioned on the data. The benefit of hierarchical models is that they account for group-level structure in the data within a single model. We can thus estimate regional or local effects with respect to a population-level model learned from all data regardless of their location. Hierarchical models offer a compromise between separate models that overemphasize regional and local effects and that are independently learned for each group, and pooled models that are learned from all data without distinction71. Similarly, repeated inventories reveal recent shifts in the regional size distribution of ice-dammed lakes, but little about trends in lake outbursts49. By using quantile regression, we examined whether and by how much the quantiles in the conditional distributions of reported peak discharge, Qp, and flood volume, V0, have changed in our six study regions. Extreme (>90th percentile) flood discharges are important for planning flood protection measures and informing flood risk zoning69. Ordinary least squares regression estimates the conditional mean, but quantile regression makes no assumptions about the distribution of the response variable and is robust against outliers. In our model specification, we used an asymmetric Laplace likelihood (AL) with fixed quantiles. The AL has densityy is the response variable, μ is a location parameter, κ is a positive scale parameter, 0 < p < 1 is a percentile, and I(∙). The exponent takes the values y ≥ μ and y < μ. We modelled the conditional distributions of Qp and V0 with decimal year t for two fixed values of p asyji are reported values of Qp or V0 with yji referring to the ith observation in group j, nj is the number of observations in group j, and J is the number of groups. The parameters αj and βj are the group-level intercepts and slopes, respectively, and α and β are the corresponding population-level parameters. The covariance matrix S is composed of group-level standard deviations σα and σβ, and R, the correlation matrix with correlation ς. In line with decadal analyses of median and extreme flood discharges70, we considered fixed values of p = 0.5 (median) and p = 0.9 (90th percentile), and estimated all other parameters from the data.Continental and global studies of river floods point to climate-driven changes in both median and extreme discharges in past decadesThe Bayesian framework demands prior distributions for each parameter that enters at another model level. We chose the following priors10-transformed response variables Qp and V0, and a standardized predictor  with zero mean and unit standard deviation. Our choice of a zero-mean Gaussian with standard deviation of 2.5 admits both negative and positive trends for β, expressing the contrasting trends reported for the size of ice-dam failures in recent decades72. The Lewandowski–Kurowicka–Joe (LKJ) Cholesky correlation distribution prior for R makes all correlation matrices equally likely.These priors refer to standardized, log73 that is called via the software package brms74 within the statistical programming language R75.For a fixed quantile, the joint posterior distribution can be thus written asquations –6) and  and 13\dquations –12). We. We13\doJ = 22 lakes (Qp) and J = 26 lakes (V0) that produced at least five outbursts each between 1900 and 2021. For these models, we focused only on the trends in median flood discharges, given that lakes with few reported GLOFs have few samples that exceed high thresholds.We used the same multi-level structure of the quantile regression model to determine how flood discharges have changed for individual lakes. To this end, we conditioned the model on Z of glacier-dammed lakes against the decimal year of GLOF occurrence t, conditioned on the J = 6 regions.Finally, to test whether more recent GLOFs originated from progressively higher elevations, we selected for each lake the year of the first reported GLOF, given that many ice-dammed lakes burst out repeatedly. As for our hierarchical models on GLOF magnitudes, we used quantile regression to determine the trend in the median elevation Qp, V0 and Z with three parallel chains that drew 6,000 samples with 2,000 warm-up runs each. We found no numerical divergences after warm-ups, which were supported by the Gelman–Rubin potential scale reduction factor We ran all regional and local quantile regression models on mentclass2pt{minimd (doy) from the linear predictor year t (ref. 64). The VM distribution has densityy are the observed data, ϑ is a location parameter, φ is a positive precision parameter and I0 is the modified Bessel function of the first kind of order 0.Measuring temporal changes in GLOF timing must consider that the response variable doy can recycle through the observation period, given that calendar day 0 is equal to day 365. The von Mises (VM) distribution is a close approximation to a wrapped normal distribution for circular data and allows estimating the angular response d to t to a zero mean and unit standard deviation, and estimated the trend in GLOF timing asyji are reported values of doy, with yji referring to the ith observation in group j, ϑji is the corresponding location parameter, and ζj and ηj are the estimated intercepts and slopes, respectively. We used the default Gamma prior in brms to estimate the precision parameter φj. This model was fit to each group separately without partial pooling of parameters across groups, because the distinct seasonal differences in GLOF timing in the two hemispheres  satellite instrument intersecting glaciers during the period of 2000 to 2019. We stacked the ASTER DEMs in temporal order and further added high-resolution data from the ArcticDEM77 to the time series. Data from ArcticDEM cover glacier dams in Alaska, Iceland and Scandinavia . The elevation change uncertainties were estimated using a framework that accounts for heteroscedasticity , which more reliably describes errors depending on terrain slope and the quality of stereo-correlation. The framework also accounts for spatial correlation of errors using multiple correlation ranges that better describe ASTER instrument noise79. These uncertainties were extensively validated using independent high-precision data from NASA’s Ice, Cloud and land Elevation Satellite (ICESat) and IceBridge missions, as well as LiDAR acquisitions8. Supplementary Table The length and thickness of the glacier dam are important diagnostics for predicting flood magnitudes and timingJ = 13 glacier lakes that burst out repeatedly (n > 5) between 2000 and 2019. For each dated outburst within a GLOF cycle, we obtained the closest temporal estimate of the cumulative elevation change of the glacier dam. We then fitted a hierarchical quantile regression model, that is, the same as in equations prior distributions as in equations . We. WeJ = 1edly n >  between Any methods, additional references, Nature Portfolio reporting summaries, source data, extended data, supplementary information, acknowledgements, peer review information; details of author contributions and competing interests; and statements of data and code availability are available at 10.1038/s41586-022-05642-9.Supplementary TablesThis file contains Supplementary Tables 1–6.


The corresponding changes in simulated surface temperature are found to be most prominent on continental regions which amount to several degrees in Kelvin. Our results indicate the importance of choosing a reasonable ice cloud optical property parameterization in climate simulations.The representation of ice cloud optical properties in climate models has long been a difficult problem. Very different ice cloud optical property parameterization schemes developed based on very different assumptions of ice particle shape habits, particle size distributions, and surface roughness conditions, are used in various models. It is not clear as to how simulated climate variables are affected by the ice cloud optical property parameterizations. A total of five ice cloud optical property parameterization schemes, including three based on the ice habit mixtures suitable for general ice clouds, mid-latitude synoptic ice clouds, and tropical deep convective ice clouds, and the other two based on single ice habits , are developed under a same framework and are implemented in the National Center for Atmospheric Research Community Atmospheric Model version 5. A series of atmosphere-only climate simulations are carried out for each of the five cases with different ice parameterizations. The differences in the simulated top of the atmosphere shortwave and longwave cloud radiative effects (CREs) are evaluated, and the global averaged net CRE differences among different cases range from − 1.93 to 1.03 Wm Because of the intricate complexities in ice cloud, it remains a big challenge to accurately calculate the optical properties of ice clouds and subsequently well simulate the ice cloud radiative impacts7. The complexity of ice cloud problem lies in its versatile of ice habits, wide range of ice particle sizes, and various degrees of ice surface roughness as well as internal inhomogeneity11.Ice clouds distribute globally and exert remarkable impacts on climate23. A frequently used ice cloud particle model is the single hexagonal column with smooth surface24. Ice habit mixtures are also proposed and used in a couple of studies. For example, the ice cloud model for MODIS (Moderate Resolution Imaging Spectroradiometer) collection 5 cloud property retrieval25, the general ice habit mixture model26, the two-habit model27, and various other35. Advances in the calculations of the optical properties of ice particles were summarized in more details in Baran37 and Yang et al.9. The MODIS science team however adopted a single-habit ice cloud particle model for the MODIS Collection 6 ice cloud retrieval algorithm2 . The C6 ice cloud model is a severely roughened hexagonal column aggregate that encompasses the non-spherical characteristics and surface roughness features of real ice cloud particles, as compared to the ice cloud particle model of MODIS Collection 5. It is not only implemented in the latest MODIS cloud product retrievals but also incorporated into fast radiative transfer models and significantly improves the ice cloud modeling capabilities for various satellite sensors39. Yi et al.41 also applied the C6 ice and liquid water cloud models in the broadband radiative transfer models, and achieved better simulation performances in deriving the top of the atmosphere (TOA) cloud radiative effect (CRE) in comparison with Clouds and the Earth’s Radiant Energy System (CERES) observations. Although some studies43 found that the C6 ice cloud model exhibited inconsistent performances in the mid and far infrared regions, it generally provided reasonable results for broadband simulations. Apparently, the present status of implementing various kinds of ice cloud optical property parameterizations in remote sensing and modeling studies could induce large uncertainties in the applications32.As a result, selecting a valid ice cloud particle shape model for remote sensing and climate modeling studies became one of the most important but difficult questions. Many studies endeavored to seek for an appropriate solution, for example, spherical ice particle approximation and various non-spherical ice particle habits were used in previous ice cloud property parameterizations46. Yi et al.47 explored the influence of ice particle surface roughening on the global cloud radiative effect. They estimated a large shortwave (SW) globally averaged CRE of 1–2 Wm−2 and a small but non-negligible longwave (LW) CRE due to ice crystal surface roughness. Regional CRE differences could be even larger and possibly exerted noticeable impacts on simulated climate. In the comprehensive review by Yang et al.9, they compared two climate simulations with assumptions of spherical and non-spherical ice cloud optical parameterizations. They derived a generally warmer climate especially over land with spherical ice cloud assumption. Baran et al.48 found the impacts of coupled cloud physics-radiation parameterization on general circulation models could be quite significant. Zhao et al.49 reported large differences in the simulated CREs, vertical heating rate, precipitation, and atmospheric circulation among various model runs with the Community Earth System Model (CESM) default29, Fu14, and Baum-Yang26 (the GHM case in this study) ice optical properties. Järvinen et al.50 replaced the ice optical properties used in the ECHAM–Hamburg Aerosol Module (ECHAM-HAM) general circulation model with those of a new parameterization and found that the complex ice crystal case exerted an additional cooling effect of 1.12 Wm−2 on the global radiation budget. However, such comparison studies are often based on very different ice parameterizations. Not only the ice habits and particle size distribution are different, but also many other factors including the ice refractive indices, the treatment of ice surface roughness conditions, and the definitions of ice cloud effective diameter (radius), are interfering the overall results of the simulated CREs and the climate states. In other words, the induced changes in simulated climate states and variables could be biased in previous studies. Note Baran et al.32 made significant efforts to explore the inconsistencies of assumptions involved in the cloud physics and radiation without using the concept of effective diameter, which shed some light on solving this problem from another angle. This study aims at evaluating and quantifying the impacts of various ice cloud particle models developed under a same framework with considerations of different degrees of complexities to constrain the uncertainties associated with ice cloud habit models.The model simulated climate states and variables are closely related to how the ice cloud optical properties are parameterized and how large the CREs exert on the climate system. The cloud physics and radiation process modeling in general circulation models still contained a lot of uncertainties in comparison with observationsFigure 52.It is found that the mass extinction coefficient exponentially decreases with the increase of effective particle diameter at all radiation bands. The most prominent differences between the GHM and the other four cases exist when the effective diameter is under 60 μm, while almost no difference in mass extinction coefficient is found for large particles. Except for the ASC case, the MLC, TDC, and SCN cases exhibit larger value of mass extinction coefficients for the smaller particles with effective diameters lower than 60 μm. These results are similar as those of previous studiesThe single-scattering albedo (SSA) of the GHM is almost a constant for selected SW bands regardless of the effective sizes of the particle while the other bands show decreased SSA as particle sizes increase. This means ice clouds with larger effective diameters become more absorptive than the smaller ones. All four other cases show some perturbations in single-scattering albedo at various particle sizes and bands, but these perturbations are generally small (< 0.03) and negligible.The asymmetry factor for the GHM generally increases with the increase of effective particle diameter for all SW bands where the increase rate is higher for some bands than the other. That means the forward scattering of radiation gradually strengthens with the increase of effective particle size. The MLC and SCN have very similar variation pattern as the GHM where the differences in asymmetry factor are lower than 0.02. The TDC however has higher asymmetry factor from the visible to near infrared bands where the largest difference exists around effective particle diameter of 70 μm. This is related to the larger fractions of aggregates of plates when the TDC particle size increases, which strengthen the forward scattering. Conversely, the ASC has remarkably lower asymmetry factor than that of the GHM and possesses the lowest asymmetry factor among all cases, because the severely roughened column ice aggregate is highly complex in shape and in surface condition which bring down the forward scattering. As the effective particle size increases, the difference in the asymmetry factor also increases, due to the lower increase rate of asymmetry factor with effective size in the ASC as compared with that of the GHM.The mass absorption coefficients at the LW bands follow similar exponentially decreasing variation pattern with increasing effective diameters as the mass extinction coefficients at the SW bands, but different LW bands have different decreasing rate. The ASC also has the most distinct feature in that lower mass absorption coefficients are found as compared with those of the GHM at the smaller effective particle sizes.53. In this study, we find that the diagnosed ice cloud effective diameters in the five simulation cases are similar and no significant changes exist among them. This is verified by examining the model simulated ice cloud physical properties within the Cloud Feedback Model Intercomparison Project Observation Simulator Package (COSP) results  CREs  will perturb the SWCRE and LWCRE differently. This means using the ice cloud models suitable for certain regions to represent the global ice clouds could be problematic. According to the previous studiesThe combined effects of SWCRE and LWCRE are reflected in terms of the surface temperature changes in Fig. Although the globally averaged net CRE difference between SCN and GHM cases is almost zero, the STDs still show some features of positive patterns because the SWCRE and LWCRE differences unevenly distribute in the horizontal space. Generally, the STDs between SCN and GHM are similar as those between MLC and GHM except that broader areas with significant changes over North America and North Asia are found.Broadly warmer surface temperature almost over all continental regions are found because significantly weaker SWCREs are globally found in the TDC case, except for Australia where particularly stronger SWCRE is present Fig. e. The reThe ASC case shows much stronger SWCREs globally, especially over the tropical and midlatitude oceans. An overall decrease in the surface temperature is evident from Fig. In summary, the most significant changes in surface temperature correspond well with the largest changes in the TOA CRE for all cases. However, it should be noted that there are several regions where the CRE differences and the STDs do not match. This indicates that the CRE is not the only driver of the STD, and the other factors should be considered to better understand the modeling results.It is evident to find that the differences in the simulated surface temperature are mostly related to the differences in the local net CREs. However, the net CREs are determined not only by the cloud optical properties but also how the cloud particle sizes and cloud water are distributed horizontally and vertically. Considering that the simulated cloud fields among the five simulations are not significantly different  do not necessarily give very different results in that their optical properties are similar and thus the simulated CREs and surface temperatures are also similar. Different ice habit mixtures focusing on different types of ice clouds  whereas result in quite different responses in the SWCREs where they are overestimated in the MLC case and are underestimated in the TDC case. A single-habit ice cloud model of ASC differs from the ice cloud model of SCN by resulting in much stronger SWCRE and relatively lower LWCRE.−2, but the difference in SWCRE could change the sign of number depending on the exact ice habits included in the ice model. A single-habit ice cloud particle model (ASC), which is found to be suitable for ice cloud property remote sensing retrievals, could induce additionally stronger SWCRE resulting in global surface cooling which amount to − 2 Wm−2 in SWCRE and several degrees of regional surface temperature reduction. Note our results of the CRE differences and the STDs are smaller than previous results like Zhao et al.49 This is because the previous studies mostly include more contributing factors like ice refractive indices and particle size distributions, which diverse remarkably among different ice optical property parameterizations. Given the model results depict quite different response in the simulations, special attentions should be exercised when different model simulations are compared, or when satellite observations and retrievals are used as truth for validation against model results. Additional hidden biases in cloud radiation effects are possibly influencing the climate feedbacks. Note also that if a coupled model is used, the impacts of ice cloud optical property parameterization over ocean could be intensified by the air-sea interaction and further induce greater changes in the surface temperature. Further studies about unifying the ice cloud scattering properties used in remote sensing and modeling communities are eagerly needed. There is still much work to be done to obtain full unification between climate models and remote sensing although some early attempts have been made55.In summary, we conclude that ice habit mixture models which are developed to be analogous to real ice clouds found at different regions of the globe could induce SWCRE difference within 1 Wm26 namely, General Habit Mixture (GHM), Midlatitude habit mixture (MLC), and Tropical Deep Convection (TDC), as well as two single-habit ice cloud particle models, namely, Aggregate of Severely roughened column (ASC) and Single Column (SCN)  could reveal different implications of the influences of ice cloud complexities on simulated climate.There are ample discussions of what kinds of ice cloud particle models should be used for remote sensing retrieval and climate model simulations in the previous research studies. The selections of ice particle models here enable detailed examination of the impacts of various ice particle models with different complexities under a same framework. Specifically, the GHM can be regarded as the overall ice cloud model suitable for general and global use. The MLC and TDC, however, can be treated as the subsets of the GHM as they only focus on the midlatitude and the tropical deep convective ice clouds, respectively. The ASC is the same ice cloud model as that is used in the MODIS collection 6 ice cloud satellite retrieval. The SCN is an ice cloud model analogous to that of the Fu parameterization scheme57 to develop the five ice optical property parameterization schemes and to implement them in the model experiments. Single scattering properties of ice crystals are derived from a comprehensive database developed by Yang et al.58 and Bi and Yang59 using the latest light-scattering computation techniques of Invariant Imbedding T-matrix Method and Improved Geometric Optics Method60 in which a same set of ice refractive indices are used in the calculations. The bulk ice scattering properties used in CAM5 including the mass extinction and absorption coefficients, single-scattering albedo, and asymmetry factor, are parameterized as functions of the ice cloud particle effective diameter in the range of 10–120 μm. The effective diameter61 is defined as:D is the single ice particle maximum dimension, Dmin and Dmax are the lower and upper limits of the ice particle dimension, Ai and Vi are the projected area and volume of the single ice particle with the ice shape i, fi is the fraction of ice shape i which varies with the size of ice particle  cloud diagnostics62 are enabled in the simulations to provide suitable simulation results for comparison with satellite retrievals of cloud properties. Only the last 10 years of simulation results are analyzed with the Atmosphere Model Working Group diagnostics package for diagnostic purposes. The GHM simulation case is treated as the controlled experiment and the other cases are compared with the controlled experiment to discern the various features associated with the optical property changes. Also note that the longwave cloud scattering effect is not considered in the radiative transfer modeling in CESM which may induce some biases in the longwave cloud radiative effect65.The CAM5.3 model is the atmospheric component of the CESM (Community Earth System Model) version 1.2.2 developed by NCAR . In this study, we carry out five numerical experiments with CAM5.3 implementing five different ice cloud optical property parameterization schemes respectively to replace the default schemeSupplementary Information.


Advancements in our knowledge base surrounding the type 2 immune response, production of IgE and maintenance of immunological memory has led the field to explore targeted intervention of allergic pathways using monoclonal antibodies (mAbs). Intervention at various stages of the allergic cascade offers the opportunity to prevent initiation and/or maintenance of the type 2 immune response and effectively provide therapeutic benefit to patients. Furthermore, a better understanding of the protective mechanisms involved in allergen specific immunotherapy (AIT) has led us to appreciate the interplay of immunoglobulins in the allergic response, specifically the benefit in shifting the IgG:IgE ratio in favor of functionally relevant blocking IgG. Thus, treatments that lower IgE or boost IgG with the ability to outcompete IgE binding to allergen also present a favorable approach in the treatment of allergy. In this short review we discuss and highlight recent advances in the use of biologics to treat severe allergy, highlighting the key challenges but also the significant opportunities and advances to date.Over the last 4 decades there has been a significant global increase in the incidence and prevalence of IgE-mediated allergy. Although much progress has been made in the management of allergy  Over the last 4 decades there has been a significant increase in the incidence and prevalence of allergy across the globe creating a significant burden on patients, healthcare providers and society. It was recently estimated that allergic rhinitis (AR) alone affects 10%–30% of the population worldwide, with rates as high as 50% in some countries . Althoug+ T helper type 2 cells (Th2) results in recruitment of inflammatory effector cells , goblet cell hyperplasia, mucus secretion and antibody class switch in favor of IgE production -25, thymic stromal lymphopoietin (TSLP), and IL-33 that are released at sites of initial allergen exposure as well as downstream production of IL-4, IL-13, IL-5 and IL-9. Subsequent differentiation of CD4oduction , 9. Acutoduction , 11.via pharmacotherapeutics targeting symptom control  and humoral response . In a sePassive immunotherapy with antibodies against antigens is a treatment approach that has long been utilized in various settings. Its utility has extended to targeted treatment and prevention of viral infection using purified monoclonal antibodies (mAbs) with the advent of Palivizumab, a single mAb treatment for respiratory syncytial virus  and, morThe concept of passive administration of allergen specific blocking mAbs for the treatment of allergy was first validated in a small proof of mechanism study in cat allergic individuals and extended to a study in birch allergic individuals shortly thereafter , 18. SpeNotably, vaccines for the treatment of allergy also rely largely on the induction of blocking IgG, as do emerging AIT approaches aiming to achieve protective effects whilst limiting the risk of IgE-mediated side effects through the use of allergen components or allergoids modified to reduce allergenicity yet maintain an ability to mount humoral responses towards functional blocking IgG –60. AlthFundamental to this is approach is a robust understanding of the structural basis of allergens and allergen antibody interactions. Multiple epitopes of an allergen likely need to be blocked to achieve robust inhibition of allergic effector cell activation. Although it has been shown that maximal coverage of an allergen is not necessary to achieve blockade of the IgE mediated response , 55 defiOther approaches target cytokines involved in the development and/or maintenance of allergy. Of particular interest are type 2 cytokines, such as IL-4, IL-13 and IL-5 and the epithelial cell-derived cytokines IL-25, TSLP, and IL-33 that are released at sites of initial allergen exposure .α) inhibits signaling of both IL-4 and IL-13 and is approved for the treatment of atopic dermatitis, asthma, chronic sinusitis with nasal polyps and eosinophilic esophagitis , patients received 52 weeks of treatment followed by 52 weeks of observation off therapy. As tolerance induction was the goal, the primary endpoint of the study was defined as a significant reduction in TNSS in response to NAC in the cat-SCIT with tezepelumab group as compared to cat-SCIT alone at week 104 following completion of 52 weeks on therapy and 52 weeks with no treatment. Although those who received cat SCIT with tezepelumab did achieve a significant reduction in TNSS in response to NAC as compared to cat SCIT alone during treatment week 25 and 52), the effect was not sustained following completion of therapy (week 104) and thus the study did not meet its primary endpoint , short study duration, high dropout rate and an imbalance in baseline characteristics warrants a more comprehensive interrogation to determine a role for IL-33 in food allergy. Itepekimab is an additional fully human IL-33 neutralizing monoclonal antibody under clinical development. Although not yet evaluated for the treatment of allergy, it was shown to affect a lower incidence of loss of asthma control vs. placebo and improved lung function in a ph2 study for moderate to severe asthma  in comparison to placebo (0% at day 15 and 45). Reported differences in select biomarkers further suggest etokimab may interfere with downstream allergic pathways  . While pe asthma , 66 as we asthma  patientsWe have more to learn about the role of type 2 and epithelial cytokines as the drivers of established disease especially in the context of AIT. These studies have only begun to scratch the surface of our understanding with several additional clinical trials actively ongoing, evaluating various treatment regimens as well as interventions at the point of prevention in high-risk individuals (AD patients/genetic risk factors).IgE is the immunoglobulin subclass that plays the central role in acute allergic hypersensitivity therefore presenting as an overt target for the treatment of allergy . OmalizuMore recently, studies have focused on using omalizumab in combination with immunotherapy to enhance efficacy and safety of such tolerizing approaches. AIT in combination with omalizumab for the treatment of AR was first evaluated in 2002 in a randomized double blind placebo controlled (DBPC) study of 221 children with birch and/or grass pollen allergy. Omalizumab in combination with SCIT reduced symptoms by 48% over 2 pollen seasons when compared with SCIT alone . AdditioClinical trials evaluating Omalizumab as an add on to oral immunotherapy (OIT) for food allergy have also been conducted with a primary focus on milk, peanut and more recently multifood OIT . Early sThe next generation anti-IgE molecule, ligelizumab, a humanized monoclonal IgG1 mAb recognizing an IgE-epitope distinct from that of omalizumab, is also in clinical development for the treatment of allergic disease . Ligelizα, inhibits IL-4 and IL-13 signalling and inhibits class switching to IgE shows approximately a 70 percent reduction in IgE after one year (While anti-IgE therapy shows promise as a potential treatment option for patients with severe food allergies, identifying and targeting the source of IgE also offers promise. Clinical observations support the concept that such a source exists that maintains levels of circulating allergen specific IgE. For example, allergy can be transferred during a bone marrow transplant and persists long term , 78. It one year . These fone year . This fiTargeted intervention in the prevention, initiation, or maintenance of the type 2 immune response holds the potential to effectively provide therapeutic benefit to patients. Understanding the interplay of immunoglobulins in the allergic response and effectively shifting the IgG:IgE ratio in favor of functionally relevant blocking IgG with the ability to outcompete IgE binding to allergen presents one favorable approach to provide protection. To treat allergy more broadly, directly targeting IgE or allergic pathways and cytokines involved in its production and maintenance offers promise. Overall, these studies highlight key mechanistic similarities and differences driving the allergic response and collectively emphasize the need for more studies in this space.


Over the last 2 decades, omalizumab is the only anti-IgE antibody that has been approved for asthma and chronic spontaneous urticaria (CSU). Ligelizumab, a higher-affinity anti-IgE mAb and the only rival viable candidate in late-stage clinical trials, showed anti-CSU efficacy superior to that of omalizumab in phase IIb but not in phase III. This report features the antigenic-functional characteristics of UB-221, an anti-IgE mAb of a newer class that is distinct from omalizumab and ligelizumab. UB-221, in free form, bound abundantly to CD23-occupied IgE and, in oligomeric mAb-IgE complex forms, freely engaged CD23, while ligelizumab reacted limitedly and omalizumab stayed inert toward CD23; these observations are consistent with UB-221 outperforming ligelizumab and omalizumab in CD23-mediated downregulation of IgE production. UB-221 bound IgE with a strong affinity to prevent FcԑRI-mediated basophil activation and degranulation, exhibiting superior IgE-neutralizing activity to that of omalizumab. UB-221 and ligelizumab bound cellular IgE and effectively neutralized IgE in sera of patients with atopic dermatitis with equal strength, while omalizumab lagged behind. A single UB-221 dose administered to cynomolgus macaques and human IgE –knockin mice could induce rapid, pronounced serum-IgE reduction. A single UB-221 dose administered to patients with CSU in a first-in-human trial exhibited durable disease symptom relief in parallel with a rapid reduction in serum free-IgE level. There remains an unmet medical need for a diverse array of allergic diseases, of which the combined disease prevalence has substantially increased to affect more than 30% of the world’s population, causing global health threats and mounting economic burden , 2. AlleDK, ~10–10–10–11 M) to FcԑRI  to a single chain (monomeric)  approaching that of the IgE-FcԑRI interaction  , 14 of tnomeric) –17. Sincnomeric) , 16–18. eraction , 20.Given its limited effects against worms and cancer , 22, IgEhttps://www.hcplive.com/view/phase-3-ligelizumab-not-superior-omalizumab).Omalizumab is the only anti-IgE antibody approved to date and is restricted to serve as a third-line add-on therapeutic for moderate-to-severe persistent allergic asthma (approved 2003), chronic spontaneous urticaria (CSU) (approved 2014), and nasal polyps (approved 2020) . New antA new class of anti-IgE mAb, 8D6 (the murine mAb of the humanized UB-221), was found not to interfere with IgE binding to CD23 , 37, forMoreover, UB-221 binds IgE with a higher affinity than omalizumab and is superior in IgE neutralization and prevention of basophil degranulation. UB-221 and ligelizumab neutralize high serum IgE of patients with AD with equal strength, while omalizumab is less effective. In cynomolgus macaques and human IgE –transgenic (hIGHE-knockin) mice, a single dose of UB-221 can induce a rapid, pronounced reduction in serum IgE. In addition, UB-221 in a phase I single-dose clinical trial involving patients with CSU has demonstrated durable disease symptom relief  that associates with a rapid reduction in serum free-IgE level.1 mAb, was previously reported to neutralize IgE and bind to CD23-bound IgE (https://doi.org/10.1172/JCI157765DS1). The humanized 8D6 was designated as UB-221. As with the prerequisite for omalizumab to be safe for therapeutic use, UB-221 does not bind to the FcεRI-bound IgE on ELISA  allergen and OVA-specific IgE, we observed that, as compared with omalizumab, UB-221 competed favorably to inhibit the IgE-OVA allergen complex–induced RBL SX-38 degranulation with 7-fold greater efficiency , as indi14 ng/mL , and a 306 ng/mL .+ SKW6.4 B lymphoma cells  can interact unrestrictedly with the IgE-CD23 complex (or CD23). Free ligelizumab can react with the IgE-CD23 complex only limitedly, while in the IgE-mAb complex form it loses its capability to bind CD23. Omalizumab in either free or complexed form is completely inert toward CD23.Of note, the UB-221–IgE complex could bind to CD23  with dif3(IgE)3 detected at approximately 21.5 S (1(IgE)2. When mAb was in excess, smaller complexes and a large peak at approximately 7 S corresponding to the monomeric IgE were detected; a major mAb-IgE complex was detected at approximately 13 S and likely represents the heterotrimer (UB-221)2(IgE)1.In PBS and serum, at a 1:1 molar ratio, the most abundant complex probably corresponds to the 3:3 heterohexamer (UB-221)y 21.5 S . A 3-fol1(IgE)1 when the UB-221/IgE molar ratio is 10:1, 50:1, or higher. Pharmacokinetically, a single UB-221 dose would result in a dynamic range of mAb/IgE ratios spanning well over 10:1, with which the 1:1 heterodimer would predominate, in particular under a repeat-dose regimen in which most of IgE the human body produces would be rapidly mopped up by UB-221.Overall, a molar excess of either UB-221 or IgE would result in the formation of smaller complexes, while the largest complexes are formed at an equimolar ratio. The complex form would thus predominantly exist as the 1:1 heterodimer (UB-221)We investigated how the binding to CD23 would influence IgE synthesis in PBMCs of healthy donors under costimulation with IL-4 and an anti-CD40 antibody, which are known not only to trigger class switching of IgE-positive B cells but also to induce expression of CD23 , 45. UsiThe validity of the PBMC IgE method was tested in the UB-221-versus-omalizumab study at concentrations of 1, 3, and 10 μg/mL, showing UB-221’s superiority over omalizumab on days 7 and 11, with IgE reduction of 87%–94% for UB-221 and 7.9%–53.3% for omalizumab . HoweverWe then defined the effects of the 3 anti-IgE mAbs on the PBMC IgE production at protein and mRNA levels simultaneously in the presence of UB-221, ligelizumab, or omalizumab at a wider concentration range  and focused on day 11, which marked the total IgE accumulated for a time period of 11 days. The results confirm that UB-221 is superior to both omalizumab and ligelizumab in suppression of IgE protein production, relative to the PBMCs “untreated” with mAbs . UB-221 At the lower 1 and 3 μg/mL dose levels, none of the mAbs showed a statistically significant lowering effect on IgE synthesis, although UB-221 exhibited a trend of 20% to 50% reduction. Ligelizumab appeared to induce a greater IgE reduction than omalizumab, although none of the dose settings showed statistically significant differences . ExceptiThe isotype-specific suppression of IgE synthesis was observed at the mRNA level as well in PBMCs from a different set of 5 individuals. The effect of mAbs on IgE mRNA expression at doses of 1 and 20 μg/mL was investigated, with a focus on day 11. Unlike the accumulated total IgE protein produced over time, this represents the level of mRNA at a specific single time point. The result reveals that, in parallel with the reduction in fresh IgE protein production, UB-221 significantly suppressed IgE mRNA expression by 70%–75% , which i50 values at 7.9, 8.8, and 55.3 ng/mL for UB-221, ligelizumab, and omalizumab, respectively.The IgE synthesis reduction events  may be pHowever, all 3 mAbs cause the same degree of apoptosis , as show50) and omalizumab with lower affinity  that was approximately 4-fold stronger than that of omalizumab , and a dissociation rate  that was approximately 5-fold lower than that of omalizumab .In addition to the cellular IgE targeting on Ramos B cells where UB-221 and ligelizumab were observed to bind with an equal affinity , which was approximately 4-fold and approximately 14-fold greater than that of UB-221 and omalizumab, attributable to a dissociation rate  that was approximately 5-fold and 10-fold lower than that of UB-221 and omalizumab, respectively. No significant differences were apparent in the association rates  among the 3 antibodies.Ligelizumab exhibits the strongest affinity  of the ligelizumab used in the present SPR analysis   and association rates   . The lat M–1s–1) , do not Unlike the case of UB-221 versus omalizumab where their differential IgE binding affinities on SPR  translatAs IgE levels are often very high in patients with AD, we investigated the efficacy of the mAbs in lowering the high IgE in sera of patients with AD. Of 30 patients with AD, their basal serum IgE levels were grouped into 3 different ranges: low , medium , and high  . The ser90)   may requ90) . The folThe overall ex vivo data exemplified with sera of patients with AD implies that, given a potent IgE neutralizer for treatment of IgE-sensitive allergic diseases, it remains a high-hurdle task to bring down the high serum-free IgE  close to a baseline, single-digit level if the steady, high IgE supply from neosynthesis could not be kept under effective control with measures in addition to simple neutralization of IgE.n = 3) receiving a single intravascular dose of UB-221 at 5.0 mg/kg, the serum antibody concentration declined, with a mean elimination half-life of 6.3 days (UB-221 can bind to cynomolgus macaque IgE (cIgE)  and enga6.3 days , in whic6.3 days .1 class-switching B cells that can produce chimeric IgE. In these mice (n = 6) receiving a single i.p. dose  . The study participants in 5 dose cohorts   were moncipants) .A single UB-221 dose, which decreased dose dependently in circulation with a half-life estimated to be 16 to 22 days at doses of 0.6 to 10 mg/kg , inducedFrom the perspective of individual study participants, in all 13 participants with moderate to severe CSU (UAS7 score ≥ 16) at baseline, a rapid reduction in UAS7 occurred in the first week ; relief The finding that FcεRI and CD23 function mutually exclusively due to reciprocal allosteric conflict , 16–18 sWhile the consequences of interaction between IgE-specific antigens  and IgE-FcεRI have been well known, precisely how a free-IgE–targeting mAb would engage CD23-bound IgE and how an IgE-complexed mAb would bind to CD23 in an unrestricted fashion have been relatively unexplored. UB-221 represents such an unprecedented, unique anti-IgE mAb of a newer class that presents 4 major preclinical findings. In addition, UB-221 in the phase I single-dose clinical trial with CSU patients has shown durable disease symptom relief along with rapid reduction in serum free IgE.First, UB-221 is superior to omalizumab over a host of IgE-neutralization studies. Without causing activation of human basophils , UB-221 DK) measured by SPR (50) to the IgE-bearing Ramos B cells  involves both allosteric and orthosteric hindrances, as previously reported  binds to IgE through a mixed protein-carbohydrate epitope , which ireported . These oreported  and in sreported  with a pThird, UB-221 in free form (or IgE-complexed form) can interact unrestrictedly with IgE-CD23 complex (or CD23) , a uniqu3) of the overlapping sites have been estimated to be 100-fold different, approximately 28 Å3 for ligelizumab versus 2773 Å3 for omalizumab  suggests that, as an IgE neutralizer, a sole factor of greater than 10-fold stronger IgE-binding affinity may not necessarily confer a better clinical outcome. In fact, omalizumab has already been operating as a striking high-affinity IgE binder, with a DK of 2.3 × 10–10 M  or complement-dependent cytotoxicity (CDC) activities, as shown in CD23-overexpressing SKW6.4 B lymphoma cells preloaded with IgE . This suWe have demonstrated that UB-221 induced a rapid, pronounced reduction in serum IgE after only a single i.v. dose in cynomolgus macaques and hIGHE-knockin mice , where UAltogether, the unique characteristics of UB-221, a combined potent IgE neutralizer and a significant CD23-mediated IgE synthesis downregulator, has translated into favorable clinical outcome in the phase I single-dose trial with CSU patients  that has demonstrated durable disease symptom relief . That UBhttps://drugs.ncats.io/drug/L8LE0L691T), was obtained from Creative Biolabs , or produced in-house at UBP in stably transfected CHO-S cells.UB-221 derived from the parental 8D6 murine mAb was generated by CDR grafting as described in the The proteins used in key bioassays, human FcεRIα-Fcγ and trimeric CD23 (ectodomain), were obtained from Academia Sinica, Taiwan. Expi293 cells were from Thermo Fisher Scientific. Human full-length IgE was purified from the culture medium of U266 myeloma cells. Cynomolgus macaque IgE Fc fragment (cIgE) and trimeric CD23 ectodomain (cCD23) were constructed in-house and expressed in Expi293 cells.L (the Fc portion of a membrane-bound long form of human IgE) was obtained from Academia Sinica, Taiwan. The B cell lymphoma SKW6.4 cell line was from ATCC.The RBL SX-38 cell line, engineered to express human FcεRI on rat basophilic leukemia cell membranes, was licensed from Harvard University. The B cell lymphoma Ramos cells stably expressing mIgE FcCynomolgus monkeys used to evaluate the effect of UB-221 (a single i.v. dose at 5 mg/kg) on serum IgE reduction was conducted in JOINN Laboratories. The hGHE-knockin mouse strain was licensed from Academia Sinica, Taiwan. The original hIGHE mouse strain F0  was crossbred with female BALB/c mice to generate the F1 hybrid mice. The human IgE levels were evaluated in 108 F1 hybrid mice between 8 and 16 week old, and mice with higher human IgE levels were selected for further studies. The mice were administered i.p. with 0.3 or 3.0 mg/kg UB-221 to test the potency of serum IgE neutralization. ELISAs of serum IgE concentrations in monkeys and mice are detailed in the The study of UB-221–IgE complexes formed in PBS solution and human serum was conducted at U-Medico, using FDS-AUC that enables the analysis of crowded solutions where absorbing molecules other than target protein are present, for which UB-221 mAb was labeled with Alexa Fluor 488 dye . The experimental procedures are detailed in The comparative PBMC IgE study was conducted for UB-221, ligelizumab (UBP lot), and omalizumab. PBMCs from fresh whole blood of 3–5 healthy donors were isolated and cultured with procedures as described above. The cells were stimulated with the anti-CD40 antibody (G28-5) (LifeSpan BioSciences) and IL-4 (R&D Systems) at a final concentration of 100 ng/mL for 11 days in the presence of 1, 3, 10, 20, or 80 μg/mL anti-IgE antibodies. Unstimulated, untreated, and human IgG antibody–treated cells served as controls. The supernatants were assayed for total IgE, IgM, and IgA by ELISA as detailed in the 6 cells/mL/well) and anti-IgE antibody concentrations (1 and 20 μg/mL). Total mRNA was isolated using a Direct-zol RNA Miniprep Plus Kit (Zymo Research). Isolated mRNA was reverse transcribed using SuperScript IV VILO Master Mix (Invitrogen). The qPCR analysis was performed using Fast SYBR Green Master Mix (Applied Biosystems) on a QuantStudio 5 Real-Time PCR System (Applied Biosystems). Expression was normalized to the endogenous control β2-microglobulin, and the relative expression was determined on QuantStudio Design & Analysis Software (Applied Biosystems). The sequences of the PCR primers for β2-microglobulin and IgE purchased from Integrated DNA Technologies were 5′-CACCCCCACTGAAAAAGATGAG-3′ (β2-microglobulin forward), 5′-CCTCCATGATGCTGCTTACATG-3′ (β2-microglobulin reverse), 5′-CCGTGTGGCACACACTC-3′ (IgE forward), and 5′-GTCGCAGGACGACTGTAAG-3′ (IgE reverse).The PBMCs from 5 healthy donors were used for the study of effects on IgE mRNA expression by UB-221, ligelizumab (UBP lot), and omalizumab. The procedures were identical to the methods described above except the cell numbers of PBMCs  were incubated for 1 hour at room temperature with UB-221, ligelizumab , or omalizumab at 1 of 3 increasing concentration ranges: 0–4,000 ng/mL for the low IgE range, 0–20,000 ng/mL for the medium IgE range, and 0–75,000 ng/mL for the high IgE range. The remaining free IgE concentrations in sera were quantitated on 96-well ELISA plates coated with FcεRIα-Fcγ. Serially diluted IgE calibration standards at 3.13 to 200 ng/mL prepared in IgE-depleted pool human serum and AD serum samples at appropriate dilution were added to the plate wells. After incubation, the plates were washed and incubated with biotin-conjugated mouse anti–human IgE mAb (BD Biosciences), followed by detection with streptavidin-poly HRP (Thermo Fisher Scientific/Pierce). The color developed with TMB substrate solution was measured at 450 nm.+ SKW6.4 cells (2 × 105 cells/well) were suspended in 100 μL of PBS containing 15 μg/mL human IgE and incubated for 30 minutes at 4°C, followed by washing twice with PBS to remove unbound IgE, and then resuspended in 100 μL PBS containing UB-221, ligelizumab (UBP lot), or omalizumab at the range of 0–10 μg/mL, and incubated for 30 minutes at 4°C. The cells were washed and incubated with 100 μL PBS containing Brilliant Violet 421–conjugated anti–human IgG Fc  for 30 minutes at 4°C. The cells were then washed twice and resuspended in a 400 μL fixation buffer at 4°C. The samples were analyzed on a BD FACSVerse instrument.The binding of anti-IgE mAbs in free form to the CD23-bound IgE on SKW6.4 cells was investigated by flow cytometry. CD235 cells/well) and incubated for 30 minutes at 4°C. The cells were then washed twice and resuspended in a 400 μL fixation buffer at 4°C. The next day, samples were analyzed on the BD FACSVerse.The binding of anti-IgE mAbs in IgE-complexed form to SKW6.4 cells was analyzed by flow cytometry. First, UB-221, ligelizumab (UBP lot), or omalizumab was conjugated with Alexa Fluor 647 using an Alexa Fluor 647 antibody labeling kit (Life Technologies). An equal volume of 15 μg/mL human IgE and anti-IgE drugs at 0 to 10 μg/mL were mixed in PBS and incubated for 1 hour at room temperature. The mixtures were added to SKW6.4 cells  were monitored for 14 weeks after dosing. Full details of the trial design, inclusion and exclusion criteria, conduct, oversight, and statistical analyses are available in the Study Protocol in the Supplemental Appendix. Laboratory assay of serum concentrations of UB-221, free IgE, and FcεRI are provided in the A phase I, open-label, dose-escalation trial to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of a single i.v. infusion dose of UB-221 as an add-on therapy was conducted in patients with CSU under the first-line H1-antihistamine treatment . The study participants in 5 dose cohorts  of the basal IgE levels between treated groups . The statistical tests were conducted using SAS software (version 9.3) and were 2-sided with a significance level of 0.05. The tests were not adjusted for multiplicity since the statistical analysis plan did not include correcting for multiplicity in this trial.The intent-to-treat population, defined as all subjects who received any amount of UB-221, was used for safety, pharmacokinetics, pharmacodynamics, and efficacy analyses. IgE levels and UAS7/HSS7 scores were summarized using descriptive statistics. UAS7 score changes from baseline were estimated by the paired The monkey study was conducted in JOINN Laboratories , which was fully accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC). The certificate number of the animal facility is SYXK (Su) 2011-0029, and the IACUC number for this study is ACU15-542. The mouse study was conducted in United BioMedical, Inc., Asia . The IACUC number for this study is AT1502.This trial was designed and sponsored by UBP and was conducted according to Good Clinical Practice at 2 sites in Taiwan. The Institutional Review Board at National Taiwan University Hospital in Taipei (IRB number 201806085MSD) and Kaohsiung Chang Gung Memorial Hospital in Kaohsiung (IRB number 201901519A0) reviewed and approved the protocol. All participants provided written informed consent before receiving any of the trial procedures.BSK, CH Li, and JBC designed and managed the preclinical research and IND-enabling studies. BSK, CH Li, and JBC contributed equally to this article. BSK, JBC, MJL, and CYW cowrote the manuscript. YYS managed the FDS-AUC based study of UB-221–IgE complex formation and conducted SPR assays and ELISAs. YJL oversaw production of UB-221 and research tool proteins. YJL and JHK were responsible for the workup of 3D structure illustrations for the mAb-IgE, FcεR1α-IgE, and mAb-IgE-CD23 molecular interfacing. YFH and MSW were responsible for method development and quantitative assay of free IgE in buffer solution and serum-associated IgE-neutralization studies. JBC, YNC, and PHT contributed to PBMC studies of de novo IgE protein and mRNA syntheses. HXH and MCL contributed to apoptosis, ELISA-, and FACS-based IgE-CD23 binding studies. JBC, YYS, HKC, and YJW contributed to the basophil activation and degranulation studies. TC performed ADCC and CDC experiments. For the clinical phase I trial, CYC and CH Lee as the clinical Principal Investigators and CH, HWS, YFL, AL, JY, and CYL from the Medical and Clinical Affairs teams contributed to the implementation of the clinical studies, and acquired and interpreted the clinical data; and FHY, CH Lin, and WT were responsible for assay development and validation, laboratory testing and data collection, and preparation of respective reports. SL, MJL, and CYW were responsible for the anti-IgE mAb clinical development plan for IgE-mediated allergic diseases. All other authors contributed to the implementation of the study and data collection. All authors critically reviewed and approved the final version. CYW had final responsibility for the decision to submit the manuscript for publication.


MYH7 gene have been associated with a number of primary cardiac conditions, including left ventricular noncompaction cardiomyopathy (LVNC). Most cases of MYH7-related diseases are associated with such variant types as missense substitutions and in-frame indels. Thus, truncating variants in MYH7 (MYH7tv) and associated mechanism of haploinsufficiency are usually considered not pathogenic in these disorders. However, recent large-scale studies demonstrated evidence of the significance of MYH7tv for LVNC and gave rise to an assumption that haploinsufficiency may be the causal mechanism for LVNC. In this article, we present a family with isolated LVNC and a heterozygous splice variant of the MYH7 gene, analyze possible consequences of this variant and conclude that not all variants that are predicted truncating really act through haploinsufficiency. This study can highlight the importance of a precise assessment of MYH7 splicing variants and their participation in the development of LVNC.Variants of the  Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by the presence of a “spongy” hypertrabeculated endocardial layer of the heart wall. During recent years, along with the improvement of instrumental diagnostics, the detectability of LVNC has been growing. First by discovering the high variability of its clinical presentation, and second by highlighting the need for genetic testing in order to avoid excessive diagnostics. It is now recognized that genetic diagnostics is necessary for correct clinical management and risk stratification in patients with LVNC . At the MYH7 (OMIM #160760), is responsible for hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), left ventricular noncompaction (LVNC), Laing distal myopathy, and myosin storage myopathy [Many genes have been reported in connection with LVNC , but onlmyopathy ,4,5. MYH7 gene (MYH7tv), which include nonsense substitutions, frameshifts, and splice donor/acceptor variants [During recent years, growing efforts are being made to distinguish the LVNC-causing genetic variants from those responsible for other types of cardiomyopathies. Recent results in this area of genetic research draw attention to predicted truncating variants in the variants .MYH7 [MYH7-related myopathic conditions [MYH7tv in LVNC pathogenesis may be underestimated. Some splice variants do not lead to a premature stop codon and, therefore, do not result in haploinsufficiency. These splice variants cause exon skipping without frame shift  and leadMYH7 ,9. In-frnditions , but notMYH7 gene. Bioinformatics analysis showed that the most likely outcome of the canonical donor splice site variant, skipping of exon 10, would result in translation of an aberrant protein product missing 33 amino acid residues, rather than premature truncation. This study presents an example of this pathogenetic mechanism in LVNC and will highlight the importance of correct estimation of genetic variants that are predicted truncation.In this article, we present a family of two generations with isolated LVNC and a heterozygous variant altering a canonical splice site in the Two generations of a family with LVNC were admitted at the National Medical Research Center for Therapy and Preventive Medicine . Family members underwent clinical examination, which included blood sample collection, biochemical and general examination, electrocardiography using 24-h Holter monitoring electrocardiogram (HM-ECG), cardiac magnetic resonance imaging (cMRI), and echocardiography (ECHO) with contrast. ECHO and cMRI imaging criteria of LVNC were applied, as previously suggested by Jenni et al.  and PetecMRI was performed with a 1.5-T imager  using a standard protocol. Breath-hold cine MRI was performed using ECG-gated segmented true fast imaging with steady-state free-precession (SSFP). Cine MRI was acquired in long-axis and short-axis planes covering the whole LV and right ventricle (RV). Late gadolinium enhancement (LGE) images were acquired in the same planes 15 min after IV injection of the gadolinium contrast agent  in a dose of 0.15 mmol/kg using inversion-recovery turbo fast low-angle shot (FLASH) pulse sequence.Molecular genetic analysis was performed in the Centre for Strategic Planning and Management of Biomedical Health Risks  as detailed by Meshkov et al. . We extrThe clinical features of the investigated patients are summarized in the 2. In blood tests, all parameters were within normal values. B-type natriuretic peptide (BNP) level was 100 pg/mL. ECG showed sinus rhythm. According to the Holter ECG, he had a sinus rhythm with the heart rate between 45–69–130 per min without arrhythmia. The patient undergoes dynamic examination, constantly takes bisoprolol 2.5 mg/day, spironolactone 25 mg/day, and torasemide 10 mg/day.In the proband III-4  mitral vThe proband‘s father (II-5), 53 y.o., underwent a cardiological examination. According to the ECHO, the heart chambers were not expanded, with an EDD of 5.4 cm, an EF of 52%, and signs of non-compact myocardium (Jenni and Chin criteria) in the area of the apex and lateral wall. According to the HM-ECG, there were no data that suggested life-threatening cardiac arrhythmias. According to the cMRI, the heart chambers were not dilated. Signs of non-compact myocardium were present.The proband’s 52-year-old mother (II-6) and 17-year-old brother (III-5) underwent a cardiological examination. According to the ECHO, the heart chambers were not dilated and there were no signs of non-compact myocardium.MYH7 gene  in the proband’s and his father’s genome, but not in the genomes of other examined relatives . We found the canonical splice site variant in the elatives . This vaelatives . A functMYH7 gene.Currently, the prognosis of the disease in patients with LVNC varies from favorable to fulminant course requiring heart transplantation . Here weMYH7 is generally considered to be tolerated. ClinGen Expert Panel recommendations discourage the use of PVS1 (“very strong”) criterion of pathogenicity for predicted truncating variants in MYH7 because such variants are thought to have only moderate impact. Thus, heterozygous predicted MYH7tvs, per se, are generally understood as non-causative [To date, haploinsufficiency of ausative .The discovered variant c.895+1G>A leads to the disruption of the canonical donor splice site after exon 10 . The analysis of the gene sequence by Mutalyzer software  showed tMYH7 variants in the cohorts of patients with LVNC. The authors compared frequencies of rare variants in six LVNC cohorts  with population control frequencies derived from gnomAD and revealed a 20-fold enrichment of predicted MYH7tv in the LVNC cases versus controls. Mazzarotto et al. also found that the predicted MYH7tv were enriched specifically in the LVNC cases, and not enriched in the HCM or DCM cohorts. Furthermore, in ostensibly healthy controls harboring predicted MYH7tv, myocardial hypertrabeculation was observed. These findings suggest haploinsufficiency to be the causative mechanism for isolated noncompaction, and attract attention of clinicians to such variants. Nevertheless, it should be noted that the conclusion about the prevalence of MYH7 haploinsufficiency in the mentioned study implied the assignment of all splicing variants to MYH7tv. Variation of the donor splicing region after exon 8 (c.732 splice region) was repeatedly revealed in different LVNC cohorts [MYH7-dependent LVNC with haploinsufficiency as a supposed pathogenetic mechanism. However, exon 8 is in-frame , and 14 of these  to LVNC, accumulation of new and existing observations in open-source databases seems essential.The of these  can be s to ExAC ), which MYH7-associated LVNC is characterized by a relatively benign clinical course in comparison to other genetic forms of the disease. The 2018 study by Waning et al. that included 327 patients with LVNC [p = 0.024), but patients with variants in MYH7 had lower probability of major adverse cardiac events compared to those with variants in other genes (p = 0.03). This conclusion was confirmed in the previously published work of Sedaghat-Hamedani et al., who revealed the relationship between poor prognosis in patients and variants in the LMNA and RBM20 genes [TTN and MYH7 genes, such a correlation was not observed [MYH7 missense variant, had moderate signs of systolic dysfunction and remodeling of the left ventricle, in the absence of intramyocardial fibrosis, which allowed us to classify those patients with a relatively good prognosis [MYH7 dominant negative variants, and the phenotypes of affected family members in the present study are consistent with it. Although in absence of the functional study we cannot confidently confirm that in our case splicing variant in MYH7 definitely leads to dominant negative effect, the concordance of clinical features with previous observations testifies to this. Co-segregation of the variant and the LVNC phenotype in two generations of the family serves as an important additional source of evidence for pathogenicity and causality of our finding.The ith LVNC  showed t20 genes . In patiobserved . In our MYH7 variants and attract attention to functional diversity of splicing alterations that now appear to be underestimated. Currently, the clinical assessment of the variants in the positions corresponding to the canonical splice sites seems to be predominantly based on the widespread presumption that splicing interruption always leads to loss of one allele. Since this mechanism is not proven to date to be significant in the MYH7-related disorders, splicing variants tend to be interpreted as VUSes without going deep into clinical features, role of the affected exons, etc. This can be seen from the majority of the existing ClinVar entries which often contain only the postulate of non-pathogenicity of MYH7tv. Moreover, recent study still defines the mechanism of pathogenicity of the alterations in c.732 splice region, adjacent to the in-frame exon of MYH7, as “unclear” [MYH7, both known and novel, need to be systematically evaluated in terms of possible consequences of exon skipping and/or other alternative splicing events. This approach could help distinguish the truly non-causative variants from previously ignored ones.Our clinical observations support the previously reported genotype–phenotype correlations of the unclear” . We propMYH7 gene should not be ignored, although their role is still not entirely clear. Continuing this theme, our finding emphasizes the importance of the distinction between truncation and frame-preserving splice site variations. We believe that accurate analysis of possible molecular consequences in the patients with splicing variants in MYH7 will expand the spectrum of known genotype-phenotype correlations and improve our knowledge of LVNC pathogenesis.Precise genetic differentiation of mechanisms underlying LVNC and its overlapping conditions is still challenging and, at the same time, important for the clinical management of affected families. Recent results suggest that truncating variants in the The main limitation of the study was that the presented genetic data were based only on DNA-level experiments and in silico analysis. We were not able to validate our predictions with RNA sequencing or to conduct any functional study of alternative splicing consequences. Furthermore, we were not able to examine all relatives and could not make cMRI to the proband’s father because of his refusal.