A child with pellagra like symptoms, amino acids in urine, family history of one siblings affected and three normal. Parents are normal. What is the diagnosis?: (A) Phenylketonuria, (B) Alkaptonuria, (C) Maple syrup urine disease, (D) Hanup's disease
Answer is D. Diagnosis is Hanup's disease. autosomal recessive (normal carrier parents with 25% of their children are affected) There is failure to reabsorb tryptophan from urine.So, tryptophan comes in urine (Aminoaciduria) . Patient has Pellagra like symptoms (as Tryptophan forms Niacin - Vitamin B3 in body). Fig:-NORMAL AND ABNORMAL ROUTES OF TRYPTOPHAN Treatment: 1. Niacin 2. High protein diet