Patient present with skin bullae on sun exposure. There is a defect in which of the following?
Xeroderma pigmentosum Autosomal recessive disorder Defective DNA repair. Increased risk for skin cancers following exposure to the UV light UV radiation- Cross-linking of pyrimidine residues,-Preventing normal DNA replication. Such DNA damage is repaired by the nucleotide excision repair system. Deficiency of UV specific endonuclease (commonest), DNA polymerase and DNA ligase
Thymidine dimers
Trinucleotide repeats
Sugar changes
DNA methylation
Genetics