A newborn baby refuses breast milk since the 2nd day of bih but accepts glucose-water, develops vomiting and severe jaundice by the 5th day. Benedict's test was positive for urine and blood glucose was low. The most likely cause is due to the deficiency of: (A) Galactokinase, (B) Aldose reductase, (C) UDP galactose 4 epimerase, (D) Galactose 1 phosphate uridyl transferase
Answer is D. The above clinical features suggest a disorder of galactose metabolism. Galactose-1-phosphate uridyl transferase deficiency leads to classical galactosemia. It is an autosomal recessive disorder. Clinical features : Accumulation of galactose-1-phosphate in the liver causes liver damage & leads to hepatomegaly, vomiting, convulsions. Accumulation of galactose-1-phosphate depletes the liver of inorganic phosphate leading to diminished ATP synthesis which affects gluconeogenesis resulting in hypoglycemia. Accumulation of galactose-1-phosphate in the nerves causes intellectual disability. Accumulation of galactitol in the lens causes oil-drop cataract. Urinary reducing sugar (Benedict's test) and Mucic acid test is positive. Treatment is galactose-free diet. Reference: Lippincott's Illustrated biochemisty 6th Edition Pg 141