[Ochronosis: report of two familial cases]

Ochronosis of alkaptonuria is a rare hereditary autosomal recessive disease in which there is an absence of homogentisic acid oxidase resulting in accumulation of homogentisic acid in tissues.

To report a new case of alkaptonuria

A 49-year-old man had been followed for 4 years for chronic lombalgia and arthropaty of two knees. He is married to his cousin and father of 4 girls. His parents are also cousins. The clinical examination has found a cutaneuous pigmentation and a lumbar stiffness. At biological checking, creatininemia was at 190 μmol/L and there are not inflammatory indicators. The radiography have shown a discal dorsolumbar calcifications, anterior inter somatic bridges and bilateral arthritis of knees without articular chondrocalcinosis. The diagnosis of ochronosis have been suspected and confirmed by the blackness of urine and the dosage of alkaptonuria. The patient has been treated symptomatiquely. Familial investigation have revealed that his daughter suffered from the same disease with the notion of blackness of urine. She is 12 year old and she's asymptomatic on the osteoarticular level.

Alkaptonuria causes a degenerative arthropaty which can endanger functional prognosis. Early diagnosis and scanning of this innate error of metabolism by genetic study play a fundamental interest, especially for molecular and genetic advisement.