Mutations that disable the DNA repair gene XPG in a xeroderma pigmentosum group G patient

The human XPG (ERCC5) gene encodes a large acidic protein thatcorrects the ultraviolet light sensitivity of cells from bothxeroderma pigmentosum complementation group G and rodent ERCCgroup 5. Here we characterize five XPG sequence alterationsand a minor splicing defect in XP-G patient XP125LO. Three ofthese changes are polymorphic variants whereas the remainingtwo, one in each XPG allele, inactivate complementation in vivo.These single point mutations provide formal proof that defectsin XPG give rise to the group G form of xeroderma pigmentosum,and their locations suggest ways in which this may occur.