All procedures were performed using the R program (http://www.r-project.org/) and the software package PLINK v1.07 {Purcell, 2007 #46}. Deviations from Hardy-Weinberg equilibrium (HWE) were tested using the exact test {Wigginton, 2005 #45} implemented in PLINK software. For each SNP, a DFAM (family-based association for disease traits) analysis was performed. This procedure implements the sib-TDT and also allows for unrelated individuals to be included (via a clustered-analysis using the Cochran-Mantel-Haesnzel); asymptotic p-values were provided for minor alleles, and presented as non-corrected. The level of statistical significance was set at 5%. Statistical power analysis was examined using software using the genetic power calculator (Purcell et al., 2003) (http://pngu.mgh.harvard.edu/~purcell/gpc/).
