This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': "Complete deficiency of UDP glucuronyl transferase is seen in - \nSelect and explain. \nA. Criggler - Najjar type - 1, B. Criggler - Najjar type - 2, C. Gilbe's syndrome, D. Dubin-Jhonson syndrome", 'role': 'user'}, {'content': "Answer: A \nExplanation: 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.", 'role': 'assistant'}]