_:vb50956424 . _:vb50956424 . _:vb50956424 . _:vb50956424 . _:vb50956424 . _:vb50956424 "An amino acid metabolic disorder that involves deficiency in histidine."^^ . _:vb50956424 "url:http://en.wikipedia.org/wiki/Histidine#Metabolism"^^ .