Nonketotic hyperglycinemia (NKH) is an autosomal recessive disorder that is characterized by rapidly progressing neurological symptoms, such as muscular hypotonia, seizures, apneic attacks, and lethargy or coma in early infancy, mostly in the neonatal period. Most patients die within a few weeks, whereas the survivors showing severe psychomotor retardation. Increased glycine concentrations in plasma, urine and, cerebrospinal fluid are biochemical features of the disorder. The primary lesion was found to be a defect in the glycine cleavage system (GCS). No specific treatment is available. Prenatal diagnosis is feasible by determining the activity of the glycine cleavage system in chorionic villi.
KeywordsGlycine Oxalate Choline Diazepam Porphyrin
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