title: Preliminary support for the oral administration of valine, isoleucine and leucine for phenylketonuria.
abstract: Recent behavioral data have demonstrated the importance of maintaining low phenylalanine concentrations beyond early childhood in patients with phenylketonuria, which can be a difficult task, particularly during adolescence. Administration of certain large neutral amino-acids (valine, isoleucine, leucine--VIL) appears to reduce phenylalanine concentrations in the cerebrospinal fluid of humans and in the brain of rats. The present study compared neuropsychological test-performance of six patients with phenylketonuria during periods of VIL administration and periods when this supplement was not given. Although individual responses to VIL were variable, there was an over-all improvement of about 1 1/2 SD in neuropsychological test performance during VIL treatment. Abstract reasoning and tactile motor problem-solving increased more than pure motor performance.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003071:Cognition / Q000187:drug effects; D004359:Drug Therapy, Combination; D004569:Electroencephalography; D006801:Humans; D007532:Isoleucine / Q000627:therapeutic use*; D007858:Learning / Q000187:drug effects; D007930:Leucine / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D010661:Phenylketonurias / Q000178:diet therapy / Q000188:drug therapy* / Q000523:psychology; D011597:Psychomotor Performance / Q000187:drug effects; D014633:Valine / Q000627:therapeutic use*
chemical_list: D007532:Isoleucine; D007930:Leucine; D014633:Valine