Homocystinuria in Adult Siblings

Homocystinuria, an inborn error of amino acid metabolism, is a rare disorder. Here, we are reporting homocystinuria in two adult siblings. The elder brother had seizures, mental retardation, marfanoid habitus and osteoporosis with multiple pathological fractures of the bones and he was operated for a dislocated lens; the younger sister had mental retardation, osteoporosis and untreated dislocated lens in both the eyes. Homocystinuria was diagnosed in both the siblings and they were started on treatment with vitamin B 6 , vitamin B 12 and folic acid. A decrease in the urine and plasma homocysteine levels with a good response was noted after treatment.