Weaker evidence of ancestry-correlated heterogeneity was observed at the CDKN2A-CDKN2B locus (PHET = 0.0022), where there were marked differences in the effects on GDM of the lead SNV between GWAS undertaken in different ancestry groups (Supplementary Material, Fig. S5, Table S4). Here, CDKN2B is linked to gestational diabetes.