Disorders of tyrosine metabolism

Abstract

Five inherited disorders of tyrosine metabolism are known, which are depicted in ◘ Fig. 18.1. Hereditary tyrosinaemia type I is characterised by progressive liver disease and renal tubular dysfunction with rickets. Hereditary tyrosinaemia type II (Richner-Hanhart syndrome) presents with keratitis and blistering lesions of the palms and soles. Tyrosinaemia type III may be asymptomatic or associated with mental retardation. Hawkinsinuria may be asymptomatic or present with failure to thrive and metabolic acidosis in infancy. In alkaptonuria symptoms of osteoarthritis usually appear in adulthood.