. . . . . . . . . . . . "[Prior studies have implicated serotonin genes in the etiology of ADHD but have not examined tryptophan hydroxylase (TPH), which is a rate-limiting enzyme in serotonin biosynthesis.]. Sentence from MEDLINE/PubMed, a database of the U.S. National Library of Medicine."@en . . . . . "2014-02-25"^^ . . "Gene-disease associations inferred from text-mining the literature."@en . "DisGeNET evidence - LITERATURE"@en . "2014-10-02T12:34:59+02:00"^^ . . . . . . . . . . . "v2.1.0.0" . "v2.1.0" .