Table 1.- Variants (SNPs) included in the PRS calculation
(Disease/Trait: Breast_cancer_estrogen-receptor_negative)
rsID	Risk allele	Effect size
rs10069690	T	0.166
rs3757322	G	0.140
rs7297051	C	0.139
rs74911261	G	0.198
Effect size: LN(OR)

Table 2.- PRS Score distribution among populations and regions
(Disease/Trait: Breast_cancer_estrogen-receptor_negative)
	count	mean	sd	se	lower.ci	upper.ci
Pyrenean regions
WEST	103	0.098	0.021	0.002	0.094	0.102
SOUTH	45	0.095	0.022	0.003	0.088	0.101
EAST	57	0.093	0.023	0.003	0.087	0.100
Populations
IBS	53	0.099	0.023	0.003	0.093	0.105
PIR	205	0.096	0.022	0.002	0.093	0.099

Table 3.- Pairwise t-test for PRS score among populations and regions
(Disease/Trait: Breast_cancer_estrogen-receptor_negative)
group1	group2	n1	n2	p	p.signif	p.adj	p.adj.signif
IBS	PIR	53	205	0.370	ns	1	ns
IBS	WEST	53	103	0.794	ns	1	ns
IBS	SOUTH	53	45	0.324	ns	1	ns
IBS	EAST	53	57	0.174	ns	1	ns
WEST	SOUTH	103	45	0.384	ns	1	ns
WEST	EAST	103	57	0.193	ns	1	ns
SOUTH	EAST	45	57	0.765	ns	1	ns
* p < .05, ** p < .01, *** p < .001

Table 4.- Chi-square test comparison of percentile counts on Pyrenean regions compared to Iberian peninsula population
(Disease/Trait: Breast_cancer_estrogen-receptor_negative)
Percentile rank	PIR				WEST				SOUTH				EAST
	adj.std.val	p.value	sig.val		adj.std.val	p.value	sig.val		adj.std.val	p.value	sig.val		adj.std.val	p.value	sig.val
pct95	−0.640	0.522	.	white	−0.420	0.674	.	white	−0.640	0.522	.	white	−1.460	0.144	.	white
pct75.95	0.380	0.704	.	white	0.370	0.711	.	white	0.380	0.704	.	white	0.080	0.936	.	white
pct50.75	−1.500	0.134	.	white	−0.470	0.638	.	white	−1.500	0.134	.	white	−0.430	0.667	.	white
pct25.50	0.440	0.660	.	white	0.620	0.535	.	white	0.440	0.660	.	white	1.090	0.276	.	white
pct25	0.820	0.412	.	white	−0.250	0.803	.	white	0.820	0.412	.	white	−0.060	0.952	.	white
adj.std.val: Adjusted standardized residuals value; p.value: P value; sig.val: statistical significance, * p < .05, ** p < .01, *** p < .001; red dash to bottom: lower counts than reference; green dash to up: upper counts than reference