This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enzymes, Subject name: Biochemistry
[{'content': 'Which of the following enzymes is deficient in Criggler Najer syndrome? \nSelect and explain. \nA. UDP glucoronyl transferase 1, B. UDP glucoronyl transferase 2, C. Bilirubin synthase, D. Heme synthase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: a (UDP-Glucronyl trans....) Ref: Vasudevan, 4th ed, 256; 5th ed,p. 268; Harper, 23th ed,p. 371In Crigler Najar syndrome there is severe deficiency of UDP-Glucronyl transferase-1.UBG: UrobilinogenUB: UrobilinSB: StercobilinTests for bile pigments:Bilirubin: Fouchets, gmelins, van den berg.Bilinogens: (UBG) Ehrlich test.Bilins: (UB + SB) Schlesingers testFew points about jaundice in children:Physiological jaundice:Occurs 24 hrs after birth. Two phases:Phase I - lasts 3-5 days. Bilirubin level will not exceed 15 mg / dl., Phase II - lasts for 2 weeks, upto 1 month in pre term infantsMost important point in physiological jaundice:Total S. bilirubin level < 15 mg / dl.Rise not more than 0.5 mg/ hr or 5 mg / dl per day.Onset after 24 hrs.Direct S. bilirubin < 2 mg / dl.Breast feeding jaundice:Rise in serum bilirubin for the first few days only.Breast milk jaundice:Due to inhibition of conjugation by substances like FFAand pregnanediol.Rise of bilirubin occurs by 7th day.Reaches maximum concentration of 10-30 mg /dl by 2-3 weeks.Temporary interruption improves condition.', 'role': 'assistant'}]