Histidinemia

Overview
Histidinemia is a rare autosomal recessive metabolic disorder caused by a deficiency of the enzyme histidase. Histidase is needed for the metabolism of the amino acid histidine. Histidenemia is characterized by increased levels of histidine in blood, urine and cerebrospinal fluid, and decreased levels of the metabolite urocanic acid in blood, urine, and skin cells.