Çakar, Nafiye EmelSeyhan, Serhat2021-01-082021-01-082020Çakar, N. E. ve Seyhan, S. (2020). Variant nonketotic hyperglycinemia caused by a novel pathogenic mutation in the glrx5 gene. Neurology Asia, 25(4), 623-626.1823-6138https://hdl.handle.net/20.500.12511/6205Nonketotic hyperglycinemia (NKH) is caused by defects in the glycine cleavage system. Hyperglycinemia without biallelic mutations in one of the 4 genes that encode the constituents of the glycine cleavage system is classified as ‘variant NKH’. The defects in these cases are in the iron-sulphur cluster biogenesis and lipoate synthesis pathways. The GLRX5 gene is one of the genes in these new pathways. We report here an 8.5-year-old male patient presented with spasticity, ataxia and optic atrophy. He lost his ability to walk after a febrile infection at the age of 1.5 year. The patient’s cognitive functions were preserved. His plasma glycine level and cerebrospinal fluid/plasma glycine ratio were high. A novel homozygous mutation p.Gly116Asp (c.347G>A) in the GLRX5 gene was identified by whole exome sequencing. In conclusion, in a child, who have neurological regression, spasticity, ataxia, and whom cognitive functions are partially preserved, if plasma glycine level is high, variant NKH should be considered in the differential diagnosis.eninfo:eu-repo/semantics/embargoedAccessGLRX5 GeneIron-Sulphur ClusterNonketotic HyperglycinemiaArticle254623626Q4Q4