p53 mutations in basal cell carcinomas.

Genomic DNA from 14 basal cell carcinoma biopsies was screened for the presence of mutations in the p53 gene, using the polymerase chain reaction followed by direct DNA sequencing. Heterozygous mutations were detected in 7 of 14 (50%) samples investigated. All mutations were G:C-A:T transitions, and five (71%) of these mutations were transitions at hot spots with CpG sites, three at codon 248 and two at codon 273. The striking similarity of the type of mutations detected in this study and with the UV mutagenesis studies reported in literature suggest the hypothesis that UV may act on the p53 gene in a carcinogenic-specific fashion.