Major Gene Effect Controls Resistance to Dental Decay in Brazil

Caries is a chronic, complex and one of the most common diseases affecting humans. Despite recent advances towards the demonstration of the existence of genetic factors influencing caries susceptibility, questions regarding the model of inheritance involved are yet to be addressed. Objectives: To describe the model of inheritance that better fits into the segregation pattern observed for Decayed Teeth (DT). Methods: A Complex Segregation Analysis (CSA) was conducted in a sample of extended multiplex families from a homogenous population recruited at the Brazilian Amazon. Prior to the CSA, impact of non-genetic covariates on DT was investigated by univariate and multivariate linear regression analysis. Results: A total of 451 individuals were enrolled in the study, distributed in 11 extended pedigrees. A major gene effect controlling resistance to phenotype was detected, with the best-fit model being dominant. The frequency of the resistance allele “A” was 0.63 and mean DT was 1.53 and 9.53 for genotypes AA/AB and BB respectively. Conclusions: The CSA is the first step towards a description of the exact nature of the genetic risk factors controlling human susceptibility to caries. Understanding of the genetic aspects of dental decay pathogenesis will lead to new strategies for prevention of such prevalent disease worldwide.