This patient came to clinic with this defect, it is in?
High-Yield Explanation
This patient present feature of Xeroderma Pigmentosum Nucleotide Excision Repair Exposure to UV rays damages DNA due to production of convalent linkages between adjacent pyrimidines. Normally the damaged DNA is repaired by excision and repair. In xeroderma pigmentosa the repair of UV damaged DNA is defective. Ref : Lippincott 5th ed