Which one of the following is not a Pyridoxine Dependent disorder: (A) Homocystinuria, (B) Methyl-malonic-acidemia, (C) Cystathioninuria, (D) Xanthurenic aciduria
Answer is B. Methylmalonic acidemia is an autosomal recessive disorder of amino acid metabolism, involving a defect in the conversion of methylmalonyl-coenzyme A (CoA) to succinyl-CoA. Patients typically present at the age of 1 month to 1 year with neurologic manifestations, such as seizure, encephalopathy, and stroke. Reference: GHAI Essential pediatrics, 8th edition