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
DNA repair defect is seen in 
Select and explain. 
A. Xeroderma pigmentosa, B. Bloom's syndrome, C. Ataxia telangiectasia, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Examples of DNA repair defects : (1) Xeroderma pigmentosa, (2) Ataxia telangiectasia, (3) Fanconi's anaemia, (4) Bloom's syndrome, (5) HNPCC.