SLC24A5 and ASIP as phenotypic predictors in Brazilian population for forensic purposes

Abstract

Pigmentation is a variable and complex trait in humans and it is determined by the interaction of environmental factors, age, disease, hormones, exposure to ultraviolet radiation and genetic factors, including pigmentation genes. Many polymorphisms of these genes have been associated with phenotypic diversity of skin, eyes and hair color in homogeneous populations. Phenotype prediction from biological samples using genetic information has benefited forensic area in some countries, leading some criminal investigations. Herein, we evaluated the association between polymorphisms in the genes SLC24A5 (rs1426654) and ASIP (rs6058017) with skin, eyes and hair colors, in 483 healthy individuals from Brazilian population for attainable use in forensic practice. The volunteers answered a questionnaire where they self-reported their skin, eye and hair colors. The polymorphic homozygous genotype of rs1426654(*)A and rs6058017(*)A in SLC24A5 and ASIP respectively, showed strongest association with fairer skin (OR 47.8; CI 14.1-161.6 and OR 8.6; CI 2.5-29.8); SLC24A5 alone showed associations with blue eyes (OR 20.7; CI 1.2-346.3) and blond hair (OR 26.6; CI 1.5-460.9). Our data showed that polymorphic genotypes (AA), in both genes, are correlated with characteristics of light pigmentation, while the ancestral genotype (GG) is related to darker traits, corroborating with previous studies in European and African populations. These associations show that specific molecular information of an individual may be useful to access some phenotypic features in an attempt to help forensic investigations, not only on crime scene samples but also in cases of face reconstructions in unknown bodies.