TABLE 1.

Genetic variance, interaction variance and their covariance component estimates for six phenotypes across POP1 + POP2 with the covariates PC1 and PC2.

UKBBdata field	Phenotype	Covariate	var(g0) (SE)	var(g1) (SE)	cov(g0,g1) (SE)	var(e0) (SE)	P-value by LRT comparing with baseline model (DF = 2)
78	Heel bone mineral density	PC1	0.3151(0.0459)	0.0124(0.0110)	0.0013(0.0120)	0.6739(0.0456)	0.1586
	(BMD) T-score, automated	PC2	0.3187(0.0460)	−0.0008(0.0047)	−0.0037(0.0110)	0.6838(0.0450)	Excluded
3144	Heel Broadband ultrasound	PC1	0.2754(0.0454)	0.0094(0.0110)	0.0087(0.0120)	0.7161(0.0454)	0.0789
	attenuation, direct entry	PC2	0.2774(0.0454)	0.0006(0.0048)	−0.0024(0.0111)	0.7232(0.0450)	0.8987
3147	Heel quantitative ultrasound	PC1	0.3151(0.0459)	0.0124(0.0110)	0.0013(0.0120)	0.6739(0.0456)	0.1597
	index (QUI), direct entry	PC2	0.3187(0.0460)	−0.0009(0.0047)	−0.0037(0.0110)	0.6839(0.0450)	Excluded
3148	Heel bone mineral density	PC1	0.3070(0.0458)	0.0107(0.0109)	0.0046(0.0120)	0.6836(0.0455)	0.1315
	(BMD)	PC2	0.3106(0.0459)	−0.0016(0.0046)	−0.0069(0.0110)	0.6926(0.0450)	Excluded
2139	Age first had sexual	PC1	0.1006(0.0266)	0.0080(0.0078)	0.0203(0.0087)	0.8909(0.0290)	5.16E−05
	intercourse	PC2	0.1012(0.0266)	0.0110(0.0057)	−0.0015(0.0087)	0.8880(0.0286)	0.0097
6138	Qualifications	PC1	0.1194(0.0235)	0.0706(0.0103)	−0.0791(0.0090)	0.8124(0.0261)	9.21E−18
		PC2	0.1778(0.0214)	0.0360(0.0059)	0.0833(0.0081)	0.7885(0.0233)	2.22E−24

The phenotypes were adjusted by basic plus additional confounders of fixed effects and transformed by rank-based INT. The G × P interaction signals of age first had sexual intercourse and qualifications were remained significant even after applying rank-based INT phenotypes, however, the other traits were not significant anymore. The estimates which were not within the valid parameter space are marked as “Excluded.” SE denotes standard error. DF denotes degree of freedom.