Complete deficiency of UDP glucuronyl transferase is seen in -

Ans. is 'a' i.e.,Criggler - Najjar type - 1Crigler-Najjar syndrome type 1 (CNS1) is the most severe form of CNS (see this term), a hereditary disorder of hepatic bilirubin conjugation, characterized by severe neonatal unconjugated hyperbilirubinemia due to a complete absence of hepatic bilirubin glucuronosyltransferase (BGT).Mutations in the UGT1A1 gene that cause Crigler-Najjar syndrome result in reduced or absent function of the bilirubin-UGT (bilirubin uridine diphosphate glucuronosyl transferase)enzyme.People with CN1 have no enzyme function, while people with CN2 have less than 20 percent of normal function.The loss of bilirubin-UGT function decreases glucuronidation of unconjugated bilirubin.This toxic substance then builds up in the body, causing unconjugated hyperbilirubinemia and jaundice.