<unk>  is caused by the abnormal and excessive accumulation of lipids in certain bodily tissues, including the liver, the heart, and muscle. Normally, these lipids are stored as lipid droplets and are normally used for metabolism, cell signaling and trafficking of vesicles.<unk>  is a disease that is diagnosed with the simultaneous occurrence of myopathy and/or ichthyosis. Myopathy is defined as a disease of the muscle tissue. Ichthyosis is a skin related disease in which the skin becomes very scaly, thick, and dry. Genetics<unk>  (NLSD) occurs in one of two genetic and clinical subtypes. Both subtypes are autosomal recessive disorders, meaning that a mutant allele must be inherited from both parents in order to cause disease. Subtype I:<unk>  with Myopathy (NLSD-M), is caused by a mutation in the PNPLA2 gene, which reduces the normal expression orfunction of the ATGL protein. PNPLA2 is located on chromosome 11. ATGL is an enzyme involved in catabolism of triglycerides (long-term fat storage) into fatty acids (short-term fat storage) within the body In the absence of fully functional ATGL, triglycerides accumulate in the bloodstream and bodily tissues. Interestingly, individuals with NLSD are not typically obese. It has been proposed that the assimilation, rather than degradation of triglycerides is the main factor in fat accumulation in adipose cells. In the absence of functional ATGL, triglycerides accumulate in the bloodstream and bodily tissues. Interestingly, individuals with NLSD are not typically obese. It has been proposed that the assimilation, rather than degradation of triglycerides is the main factor in fat accumulation in adipose cells. Patients with NLSD-M display progressive skeletal myopathy and severe cardiomyopathy in ~40% of cases. The pathophysiology and mechanistic basis of myopathy arising from deficits is lipid metabolism is not yet known. Subtype II:<unk>  with Ichthyosis (NLSD-I), or Chanarin-Dorfman syndrome, is caused by a mutation in the CGI-58 protein. CGI-58 is a coactivator of ATGL, and together these proteins sustain blood lipid levels between meals. Disruption of CGI-58 gives rise to the symptoms of ichthyosis, a dermatological condition in which skin becomes very scaly, thick and dry. Ichthyosis is an inherited disorder, like NLSD, and has been found to be genetically linked in some situations with the PNPLA2 gene. Therefore, sometimes when there is a mutation in the PNPLA2 gene, the linked allele of CG-58 is mutated as well. This specific gene, however, does not produce ichthyosis on its own. Ichthyosis can be diagnosed individually in a patient and the genetic cause for unlinked icthyosis is different from the gene linked with PNPLA2. Keep in mind these disorders may occur individually within a patient as well.
Neutral lipid storage disease
Glycogen storage disease
Inborn error of lipid metabolism
Glycogen storage disease type III
Glycogen storage disease type IV
Phospholipidosis
Glycogen storage disease type II
Glycogen storage disease type I