Despite the successes, GWAS have so far yielded sequence variants that only explain a small fraction of the estimated heritability of most of the human traits studied. Obvious contributors to the unexplained heritability, or Dark Matter, include rare variants not well tagged by common SNPs and common variants that have very small effects individually. Results presented here demonstrate that a portion of the heritability of some common/complex traits is hidden in more complex relations between sequence variants and the risks of these variants.
