Atypical nonketotic hyperglycinemia confirmed by assay of the glycine cleavage system in lymphoblasts.
A 13-year-old girl with early-onset, mild, slowly progressive mental retardation caused by nonketotic hyperglycinemia is described. The plasma and cerebrospinal fluid glycine concentrations were elevated, but the cerebrospinal fluid/plasma glycine ratio was only mildly elevated. The diagnosis was confirmed by demonstration of a defect in the activity of the glycine cleavage system in cultured lymphoblasts.
Christodoulou
J
J
Division of Clinical Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.
Kure
S
S
Hayasaka
K
K
Clarke
J T
JT
D000293:Adolescent; D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood* / Q000134:cerebrospinal fluid / Q000175:diagnosis; D002478:Cells, Cultured / Q000378:metabolism; D005260:Female; D005998:Glycine / Q000097:blood* / Q000134:cerebrospinal fluid; D006801:Humans; D008607:Intellectual Disability / Q000097:blood / Q000175:diagnosis; D008214:Lymphocytes / Q000378:metabolism*
D005998:Glycine