NORD gratefully acknowledges Harvey L. Levy, MD, Senior Physician in Medicine, Children's Hospital Boston, Professor of Pediatrics, Harvard Medical School, for assistance in the preparation of this report.
Synonyms of Histidinemia
- HIS deficiency
- histidase deficiency
- histidine ammonia-lyase (HAL) deficiency
Histidinemia is a rare hereditary metabolic disorder characterized by a deficiency of the enzyme histidase, which is necessary for the metabolism of the amino acid histidine. The concentration of histidine is elevated in the blood. Excessive amounts of histidine, imidazole pyruvic acid, and other imidazole metabolism products are excreted in the urine. The majority of individuals with histidinemia have no obvious symptoms that would indicate that a person has this disorder (asymptomatic). Histidinemia is inherited as an autosomal recessive trait.
NORD Member Organizations
1988, 1989, 1996, 2003, 2007, 2009, 2012, 2015