We utilized the Birdseed algorithm for genotype calling at both genotyping centers26,27. As 324 individuals were genotyped at both centers, we performed a concordance check. One sample showed substantial differences between the two centers, but no excess of Mendelian errors, indicating that a sample mix-up occurred in which each center genotyped a different sibling that was identified as the same sample. Excluding this sample, overall genotype concordance between the two centers was 99.72%.
