Mutations of the BRAF Gene in Benign and Malignant Melanocytic Lesions

J Invest Dermatol. 2003 Nov;121(5):1160-2. doi: 10.1046/j.1523-1747.2003.12559.x.

Abstract

A single-point mutation in exon 15 of the BRAF gene has recently been reported in a high percentage in cultured melanoma cells and in 6 of 9 primary melanomas examined. To evaluate the impact of the T1796A BRAF mutation, we screened primary melanomas, various types of nevi and lesions where a melanoma developed in an underlying nevus. We could detect the mutation in 28 of 97 (29%) melanomas and in 39 of 187 (21%) nevi, including blue nevi (0/20) and Spitz nevi (0/69), which did not carry the mutation. In melanomas with an underlying nevus, either the mutation was present in both the laser-microdissected nevus cells and the laser-microdissected melanoma cells (3/14) or both lesions were negative for the BRAF mutation except one case. In conclusion, mutations in exon 15 of the BRAF gene are nonspecific for progression of a nevus to a melanoma. Other so far unknown cofactors seem to be of importance.

MeSH terms

  • Exons
  • Humans
  • Melanoma / genetics*
  • Melanoma / pathology
  • Nevus / genetics*
  • Nevus / pathology
  • Point Mutation*
  • Proto-Oncogene Proteins c-raf / genetics*
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / pathology

Substances

  • Proto-Oncogene Proteins c-raf