A general test of association (the two-degree-of-freedom test of genotypic association) was applied, and three individual contrasts, defined by a priori genetic models (additive, dominant, and recessive), were computed. In the dominant and recessive models, explanatory variables were binary. We employed logistic regression to adjust for age and sex. No statistical correction was made for multiple comparisons in the general test of association. The LD and the haplotype frequencies were estimated with the Haploview software, version 4.2. Haplotype blocks were identified using the solid spine of LD method in Haploview and correction for multiple testing was performed using permutation correction by the Haploview program [27]. Chi-square values, ORs, and 95% confidence intervals (95% CIs) were estimated using the Statistical Package for the Social Sciences, version 17.0 (SPSS Inc., Chicago, Illinois, USA).
