[Free plasma and cerebral amino acids in children with Down's syndrome].

In 25 children with Down's syndrome, the content of free amino acids in the blood plasma, was examined chromatographically. The content of free phenylalanine, thyrosine, lysine, histidine, tryptophan, leucine and isoleucine was found to be lowered. In the brain cortex of newborn infants with Down's syndrome and increased content of cystine, alanine, phenylalanine, threonine, leucine, isoleucine, as well as double excess of gamma-aminobutyric acid were revealed.