The frequency of variants in the offspring were determined by comparison with dbSNPv132 and 1,637 whole-exome controls including 400 parents. Variants were classifed as: ‘novel’, if only a single allele was present in a parent and none were seen in dbSNP or the other control exomes; ‘rare’, if they did not meet the criteria for novel and were present in <1% of controls; and ‘common’, if they were present in ≥1% of controls.
