Merlin can only phase loci where at least one pedigree member is homozygous. We found that 50.16% of heterozygote sites could be phased for duos, 77.79% for trios and sites for pedigrees of size (Figure S2). Running times for Merlin increase exponentially as pedigree size increases (see Figure S3) but in general were not excessive on these data sets ( hour per cohort).