The analysis was performed using the Illumina 550 SNP genotype data for 1000 families from the AGRE collection. The data was obtained with permission from the AGRE [42]. Runs of homozygosity were calculated using custom scripts, allowing for no more than 2 consecutive heterozygous SNPs in a run and 3 heterozygous calls in every 10 consecutive SNPs. Intervals homozygous for the same haplotype and shared by all affected individuals were used to narrow the locus in each family.