Table 1.- Variants (SNPs) included in the PRS calculation
(Disease/Trait: Breast_cancer)
rsID	Risk allele	Effect size
rs78540526	T	0.293
rs13387042	A	0.128
rs10995190	G	0.151
rs10771399	A	0.151
rs10941679	G	0.113
rs13281615	G	0.095
rs11249433	G	0.086
rs12662670	G	0.157
rs1292011	A	0.083
rs999737	C	0.083
rs17356907	A	0.094
rs16857609	T	0.077
rs13329835	G	0.077
rs11814448	C	0.239
rs2943559	G	0.122
rs1432679	C	0.068
rs6828523	C	0.105
rs4808801	A	0.073
rs17817449	T	0.073
rs3817198	C	0.068
rs2823093	G	0.073
rs7904519	G	0.049
rs2236007	G	0.073
rs6504950	G	0.062
rs6762644	G	0.068
rs616488	A	0.062
rs941764	G	0.068
rs3903072	G	0.051
rs17529111	C	0.058
rs720475	G	0.062
rs9790517	T	0.049
Effect size: LN(OR)

Table 2.- PRS Score distribution among populations and regions
(Disease/Trait: Breast_cancer)
	count	mean	sd	se	lower.ci	upper.ci
Pyrenean regions
WEST	103	0.042	0.005	0.000	0.041	0.043
SOUTH	45	0.041	0.005	0.001	0.040	0.043
EAST	57	0.042	0.004	0.001	0.041	0.043
Populations
IBS	53	0.042	0.005	0.001	0.041	0.044
PIR	205	0.042	0.005	0.000	0.041	0.043

Table 3.- Pairwise t-test for PRS score among populations and regions
(Disease/Trait: Breast_cancer)
group1	group2	n1	n2	p	p.signif	p.adj	p.adj.signif
IBS	PIR	53	205	0.669	ns	1	ns
IBS	WEST	53	103	0.935	ns	1	ns
IBS	SOUTH	53	45	0.295	ns	1	ns
IBS	EAST	53	57	0.817	ns	1	ns
WEST	SOUTH	103	45	0.266	ns	1	ns
WEST	EAST	103	57	0.854	ns	1	ns
SOUTH	EAST	45	57	0.399	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)
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	0.210	0.834	.	white	−0.220	0.826	.	white	0.210	0.834	.	white	−0.540	0.589	.	white
pct75.95	−1.100	0.271	.	white	−1.050	0.294	.	white	−1.100	0.271	.	white	0.000	1.000	.	white
pct50.75	−0.090	0.928	.	white	1.370	0.171	.	white	−0.090	0.928	.	white	0.040	0.968	.	white
pct25.50	−0.750	0.453	.	white	−0.290	0.772	.	white	−0.750	0.453	.	white	0.190	0.849	.	white
pct25	1.640	0.101	.	white	−0.040	0.968	.	white	1.640	0.101	.	white	0.020	0.984	.	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