- A metabolic disorder characterized by speech defects, growth deficiency, and mild mental retardation in some patients; associated with elevation of blood histidine level and excretion of histidine and related imidazole metabolites in urine due to deficiency of histidine ammonia lyase or histidinase; autosomal recessive inheritance, caused by mutation in the histidinase gene (HIS) on chromosome 12q. [histidine + G. haima, blood, + -ia]
* * *his·ti·di·ne·mia or Brit his·ti·di·nae·mia .his-tə-də-'nē-mē-ə n a recessive autosomal metabolic defect that results in an excess amount of histidine in the blood and urine due to a deficiency of histidasehis·ti·di·ne·mic or Brit his·ti·di·nae·mic -mik adj
* * *his·ti·din·emia (his″tĭ-dĭ-neґme-ə) an autosomal recessive aminoacidopathy caused by mutation in the histidine ammonia-lyase gene (HAL, locus: 12q22-q23), resulting in deficiency of the enzyme; it is characterized by accumulation of histidine in serum and urinary excretion of histidine and metabolites, but is usually benign. In some cases it may cause mild central nervous system dysfunction.
Medical dictionary. 2011.