We used genome-wide complex trait analysis (GCTA26) to estimate the extent to which autosomal common genetic variation accounted for variance in AAB. GCTA estimates the genetic relationships among individuals in a sample from genome-wide SNP data, and then uses a mixed-linear modeling framework to estimate heritability. The Illumina 1M BeadChip provides sufficient coverage of variation across the genome for the purposes of estimating common SNP heritability using GCTA; accordingly, we used non-imputed genotypic data for this analysis.
