LB1478 MC1R variants and cutaneous melanoma risk in the Southern Brazil population

Abstract

Background: Melanocortin 1 receptor (MC1R) gene variants have been associated to fair skin and may independently cause an increase risk for the development of cutaneous melanoma. Objectives: To analyze the coding region of the MC1R gene in patientswith cutaneous melanoma and controls from southern Brazil and the relationship of gene variants with melanoma risk factors. Methods: We evaluated 72 patients with melanoma and 66 controls. Genotyping of the MC1R coding region was performed by sequencing in all individuals. Results: Of the 138 patients studied, 63 (45.65%) carried at least one MC1R variant. Variantswere more common in the melanoma group, with 45 cases carrying at least one variant (62.5%), while only 18 controls (27.27%). Presence of MC1R variant conferred an increase of melanoma risk. The estimated OR for melanoma was 5.05 (95% CI: 1.68 - 15.21, P=0.004) and 11.55 (95% CI: 1.74 - 76.62, P=0.011) in individuals with one and two or more MC1R sequence variants, respectively. The risk of melanoma was not modified significantly by skin phototype and hair color. Conclusions: Being a carrier of one MC1R variant is associated with an increase melanoma risk, if the individual has two or more, the risk is even higher. This predisposition is independent of phenotypic characteristics.