Replication of the 6 discovery SNPs in trios (or parent-offspring pairs).

For each target SNP, in each family we searched for trios (or parent-offspring pairs) with heterozygous offspring and determined the parent of origin of the alleles (whenever possible). From each family at most one heterozygous offspring with known parental origin was then collected and grouped according to the parental origin of the alleles. The equality of phenotypic means in the two groups was tested using a Student t-test (“P-value for beta difference column”). The difference between the phenotypic means were meta-analysed using inverse-variance weighting. Table notations: “beta meta” and “P meta”: meta-analysis estimate of beta (coded paternal) - beta (coded maternal) effect size differences and the corresponding P-value, “N meta”: total number of heterozygous offspring with (coded-maternal/other-paternal), (coded-paternal/other-maternal) genotypes, respectively.