title: BRAF polymorphisms and risk of melanocytic neoplasia.
abstract: Somatic mutations of the BRAF gene are common in melanomas and nevi but the contribution of polymorphisms in this gene to melanoma or nevus susceptibility remains unclear. An Australian melanoma case-control sample was typed for 16 single nucleotide polymorphisms (SNP) within the BRAF gene, and five SNP in three neighboring genes. The sample comprised 755 melanoma cases from 740 families stratified by family history of melanoma and controls from 635 unselected twin families (2,239 individuals). Ancestry of the cases and controls was recorded, and the twins had undergone skin examination to assess total body nevus count, degree of freckling, and pigmentation phenotype. Genotyping was carried out via primer extension followed by matrix-assisted laser desorption ionization-time of flight mass spectrometry. SNP in the BRAF gene were found to be weakly associated with melanoma status but not with development of nevi or freckles. The estimated proportion of attributable risk of melanoma due to variants in BRAF is 1.6%. This study shows that BRAF polymorphisms predispose to melanoma but the causal variant has yet to be determined. The burden of disease associated with this variant is greater than that associated with the major melanoma susceptibility locus CDKN2A, which has an estimated attributable risk of 0.2%.
authors.affiliation: Queensland Institute of Medical Research, Brisbane, Australia. michaelJ@qimr.edu.au
authors.forename: Michael R
authors.initials: MR
authors.lastname: James
authors.forename: Richard B
authors.initials: RB
authors.lastname: Roth
authors.forename: Michael M
authors.initials: MM
authors.lastname: Shi
authors.forename: Stefan
authors.initials: S
authors.lastname: Kammerer
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Nelson
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Stark
authors.forename: Troy
authors.initials: T
authors.lastname: Dumenil
authors.forename: Grant W
authors.initials: GW
authors.lastname: Montgomery
authors.forename: Nicholas K
authors.initials: NK
authors.lastname: Hayward
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.forename: Andreas
authors.initials: A
authors.lastname: Braun
authors.forename: David L
authors.initials: DL
authors.lastname: Duffy
mesh_terms: D004200:Diseases in Twins / Q000235:genetics; D005091:Exons; D005260:Female; D005787:Gene Frequency; D019942:Genes, p16; D006801:Humans; D007438:Introns; D008297:Male; D008544:Melanocytes / Q000473:pathology*; D008545:Melanoma / Q000453:epidemiology / Q000235:genetics*; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D048493:Proto-Oncogene Proteins B-raf; D012306:Risk; D012727:Sex Characteristics; D012878:Skin Neoplasms / Q000453:epidemiology / Q000235:genetics*
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf