None of the 19q13.33 top five SNPs showed statistically significant evidence for replication in an independent Australian twin family sample; however, the effect sizes shared the same direction in analyses adjusted for first time sensations. When attempting replication with all SNPs located in TRPM4 and SLC6A16 (with ±50 kb flanking regions), statistically significant association was seen in analyses adjusted for first time sensations for rs352813 (P = 9.2e‐04, surpassing the significance threshold of P = 9.43e‐04 based on the modified Bonferroni correction), located 30 kb from the top SNP rs73050610 (Table S2). Rs352813 was not statistically significant in the Finnish sample, and the direction of effect of rs352813 was different in the Australian sample when compared to the Finnish sample. Altogether 18 SNPs in 19q13.33 showed some association (P < 0.05) in both populations. Meta‐analysis of the top five SNPs did not yield genome‐wide statistically significant signals.
