In addition to quality control (QC) performed on each cohort by their respective research groups, we applied stringent filters to remove genotypes inconsistent with pedigree structure. Firstly, we ran Pedstats [33] to detect any genotypes that violated Mendelian constraints, and these loci were marked as missing for all individuals in a pedigree where violations were found. Loci that produced Mendel violations for of samples were filtered for all individuals in a cohort. Secondly, Merlin's error detection algorithm was used on all pedigrees, and genotypes which were unlikely were also flagged as missing. This final set of genotypes were used as input in all subsequent analyses.
