Classical homocystinuria: at the crossroads of specialties

Abstract

Classical homocystinuria is the second metabolic encephalopathy after phenylketonuria. Its prevalence in Tunisia is estimated at 1/32,679. This autosomal recessive disease is caused by a deficiency in cystathionine synthase on the sulfur amino acid metabolism pathway. Its clinical manifestations are heterogeneous explaining its delayed diagnosis often in adulthood. They include ophthalmological, neuropsychiatric, vascular and skeletal signs of variable intensity, isolated or associated with one another. Ophthalmologic involvement is the most frequent mode of revelation. Thromboembolic events can be life-threatening, especially stroke. Monitoring of treated patients should be carried out by a multidisciplinary team.