Xeroderma pigmentosum is caused due to defect in: (Repeat)

Ref: Chapter 7. Neoplasia; page: 275; Robbins and Cot ran Pathologic Basis of Disease: 8t>? editionExplanation:* Defective DNA - repair syndromes are set of syndrome due to defect in DNA repair genes and resultant DNA instability.* These are autosomal recessive in inheritance and include:Xeroderma pigmentosumBloom syndromeAtaxia telangiectasia.* Whereas, HNPCC is associated with inactivation of DNA mismatch repair gene, resulting in increased susceptibility to colon cancer, and cancers of Endometrium, ovary etc.,* Example for Base pair defect is Sickle cell anemia; example for Translocation defect is Philadelphia chromosome in CML - t (9:22).