In the MGS-C sample, 4.1% of the phenotypic variance in BMI was accounted for using a model including sex, ancestry based on molecular derived principal components, age, and a GRSS comprising 56 SNPs. Despite high heritability of BMI, much variance in BMI remains unaccounted for. Based on the progress in identifying loci influencing height, it is likely that a considerable portion of the ‘missing heritability’ resides in unidentified variants yet to be discovered by larger sample sizes (Yang et al. 2010). Large-scale international collaborative groups will be required to identify these additional variants with similar and smaller effect sizes.
