title: Blood-serotonin deficiency in Down's syndrome.
mesh_terms: D000293:Adolescent; D001769:Blood; D001921:Brain / Q000378:metabolism; D002648:Child; D004314:Down Syndrome / Q000378:metabolism*; D006801:Humans; D010396:Penicillamine / Q000494:pharmacology; D011736:Pyridoxine / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism
chemical_list: D012701:Serotonin; D014364:Tryptophan; D010396:Penicillamine; D011736:Pyridoxine