<unk>  can be confirmed genetically by the presence of any of the known mutations listed above. However, despite identification of 14 causative genes, the absence of a known mutation will not exclude the diagnosis, as more, as-yet-undiscovered genes can cause<unk> . Thus, the diagnosis of<unk>  is still based on clinical features. In other words, it is made when a physician feels that a person has enough of the features to warrant the label. The principal values of making a genetic diagnosis are that it guides additional medical and developmental evaluations, it excludes other possible explanations for the features, and it allows more accurate recurrence risk estimates. With more genotype-phenotype correlation studies being performed, a positive genetic diagnosis will help the clinician to be aware of possible anomalies specific to that certain gene mutation. For example, an increase in hypertrophic cardiomyopathy is seen in people with a mutation of KRAS and an increased risk of juvenile myelomonocytic leukemia exists for a mutation of PTPN11. In the future, studies may lead to a targeted management of<unk>  symptoms that depends on what genetic mutation a person has. Before birth Prenatal features that might lead physicians to consider a diagnosis of<unk>  include cystic hygroma, increased nuchal translucency, pleural effusion, and edema. Differential diagnosis While Turner syndrome has similarities with renal anomalies and developmental delay, Turner syndrome is only found in females and often expresses differently. In Turner syndrome, there is a lower incidence of developmental delays, left-sided heart defects are constant and the occurrence of renal abnormalities is much lower. Other RASopathies * Watson syndrome - Watson Syndrome has a number of similar characteristics with<unk> 's Syndrome such as short stature, pulmonary valve stenosis, variable intellectual development, and skin pigment changes. * Cardiofaciocutaneous (CFC) syndrome - CFC syndrome is very similar to<unk> 's Syndrome due to similar cardiac and lymphatic features. However, In CFC syndrome intellectual disability and gastrointestinal problems are often more severe and pronounced. * Costello syndrome - Like CFC syndrome, Costello syndrome has overlapping features with<unk> 's Syndrome. However, the conditions can be distinguished by their genetic cause. * Neurofibromatosis 1 (NF1) * Williams syndrome
Noonan syndrome
Growth hormone deficiency
Avellis syndrome
Williams syndrome
Muenke syndrome
Christianson syndrome
GRACILE syndrome
Sugarman syndrome