cerebrospinal fluid aminoacid analysis in a girl with severe psychomotor retardation , hypotonia , hyperreflexia and growth acceleration showed highly increased levels of free gamma-aminobutyric acid ( 4.8 mumol/l ; range in twenty controls 0.04-0.12 , median 0.08 ) , homocarnosine , a dipeptide of gamma-aminobutyric acid and histidine ( 23.4 mumol/l ; control range 4.0-8.7 , median 7.6 ) and of beta-alanine , an alternative substrate for gamma-aminobutyric acid-transaminase ( 0.48 mumol/l ; control range 0.02-0.06 , median 0.05 ) .
C0002520
aminoacid
C0000392
beta-alanine