Mutational analysis of the BRAF gene in human congenital and dysplastic melanocytic naevi.

Eighteen congenital melanocytic naevi (CMN) from 17 patients and 18 dysplastic melanocytic naevi (DMN) from 18 patients were screened for mutations in the BRAF oncogene (present study) and the N-ras oncogene (in the course of two foregoing studies) by single-strand conformational polymorphism (SSCP)/sequencing analysis. BRAF mutations were demonstrated in both types of lesion. As a whole, 17 of 18 CMN (94.4%) and five of 18 DMN (27.7%) harboured either BRAF or N-ras mutations. As the BRAF oncogene is frequently found to be mutated in human cutaneous melanomas, it may constitute a risk factor for melanoma formation within CMN and DMN.