DNA repair defects are seen in: (A) Xeroderma pigmentosa, (B) Bloom's syndrome, (C) Ataxia telangiectasia, (D) Li-Fraumani syndrome
Answer is A. 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