Early-onset ocular ochronosis in a girl with alkaptonuria (aku) and a novel mutation in homogentisate 1,2-dioxygenase (HGD)

摘要

Alkaptonuria (AKU) is a disorder of phenylalanine/tyrosine metabolismuddue to a defect in the enzyme homogentisate 1,2-dioxygenase (HGD). This recessiveuddisease is caused by mutations in the HGD gene. We report a 14-year-old girludwho was referred after presenting black urine. Careful examination revealed ochronosisudof the conjunctiva. There was no affection of the cardiac valves. Elevated excretion ofudhomogentisic acid in urine was found. Sequence analysis of the HGD gene fromudgenomic DNA revealed that the patient is a compound heterozygote with a previouslyuddescribed mutation (c.473C > T, p.Pro158Leu), and a novel one (c.821C > T, p.Pro274Leu).udHer mother is heterozygous for the novel mutation, while the brother is heterozygousudfor the previously described mutation. In summary, we describe an alkaptonuric patientudwith ocular ochronosis and a novel HGD mutation, c.821C > T, p.Pro274Leu.ud