This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': "DNA repair defects are seen in \nSelect and explain. \nA. Xeroderma pigmentosa, B. Bloom's syndrome, C. Ataxia telangiectasia, D. Li-Fraumani syndrome", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Xeroderma pigmentosa is autosomal recessive conditionMutation in any one of the gene XP leads to dis conditionUv light causes the formation of thymine dimers where covalent bonds are formed between thymine residues Ref: DM Vasudevan, 7th edition, page no: 584, 584', 'role': 'assistant'}]