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: Biochemistry
[{'content': "A\xa03 month old baby refuses breast milk since the 2nd day of\xa0birth,\xa0but 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: \nSelect and explain. \nA. Galactose-1-phosphate uridyl transferase, B. Beta galactosidase, C. Glucose-6-phosphatase, D. Galactokinase", 'role': 'user'}, {'content': 'Answer: A \nExplanation: The newborn infant receives high amounts of lactose, which consists of equal parts of glucose and galactose. Without\xa0the\xa0galactose-1-phosphate\xa0uridyl transferase enzyme, the infant is unable to metabolize galactose-1- phosphate, the accumulation of which results in injury to kidney, liver\xa0and brain.\nClinical features:\n\nClassic galactosemia is a serious disease with onset of symptoms typically by the 2nd half of the 1st week of life.\nWith jaundice, vomiting, seizures, lethargy, irritability, feeding difficulties, poor weight gain or failure to regain birth weight.\nHepatomegaly Oil drop cataracts, Hepatic failure.\nMental retardation.\nPatients with galactosemia are at increased risk for Escherichia coli neonatal sepsis.\n\nDiagnosis:\n\nDemonstrating a reducing substance in several urine specimens collected while the patient is receiving human\xa0milk, cow’s\xa0milk\xa0or\xa0any\xa0other formula containing lactose.\nBenedict’s test positive.\n\n\u200bReference- Harper’s illustrated biochemistry. 30th edition page -203', 'role': 'assistant'}]