Homocystinuria is a rare autosomal recessive disorder with multiple systemic manifestations and is classified into three types(1-3).Classical(type 1)homocystinuria occurs due to deficiency of cystathionine beta- synthase(CBS),an enzyme which converts homocysteine to cystathionine in the trans-sulphuration pathway in the methionine cycle which requires pyridoxal-5-phosphate as a cofactor. The other two cofactors invoved in the remethylation pathway of methionine includes folate and vitamin B12.The four major organ systems involved are the eye, central nervous system, vascular system and skeletal system. The common neurological manifestations include mental retardation, psychiatric disturbances, extrapyramidal signs and less frequently seizures. Here we report a case of homocystinuria in a child with cerebral palsy who presented with focal seizures.
