Table 1. Molecular characteristics of breast carcinomas case by case.

	Sample ID	Predisposing germline variant	MMR protein IHC	MSI status	Second hit status*	Mutations/Mb
dMMR LS-BC	BC5_31814T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	negat	MSS	L	141
	BC6_31489T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	negat	MSI	L, s	725
	BC11_31501T	MLH1 ex 16, 3.5 KB genomic deletion (Mut I)	negat	MSI	L	24
	BC11_31533T	MLH1 ex 16, 3.5 Kb genomic deletion (Mut I)	negat	MSS	L	5
	BC12_31491T	MLH1 ex 16, 3,5 kb genomic deletion (Mut I)	negat	MSI	None	22
	BC14_33229T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	negat	MSS	s	662
	BC9_33225T	MLH1 c.454-1G>A (mutation II)	negat	MSI	L	29
	BC7_33223T	MSH2 c.187delG	negat	MSI	L	15
	BC37_33228T	MSH2 ex 1-7 genomic deletion/MLPA	negat	MSI	s	12
	BC1_33203T	MSH6 ex 1-2 genomic deletion/MLPA	negat	MSS	s	35
	BC1_31528T	MSH6 ex 1-2 genomic deletion/MLPA	negat	MSS	s	246
pMMR LS-BC	BC5_31495T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	posit	MSS	None	31
	BC13_31486T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	posit	MSS	s	85
	BC4_31514T	MLH1 ex 16, 3.5 kb genomic deletion (Mut I)	posit	MSS	L	4
	BC38_31510T	MLH1 c.454-1G>A (mutation II)	posit	MSS	s	53
	BC8_33226T	MSH2 ex 1-16 genomic deletion/MLPA	posit	MSS	None	8
	BC10_33221T	MSH2 c.1738insA	posit	MSS	L	2
	BC2_31518T	MSH6 ex 1-2 genomic deletion/MLPA	posit	MSS	s	108
	BC39_33217T	MSH6 ex 1-2 genomic deletion/MLPA	posit	MSS	ND	2
	BC40_31503T	MSH6 c.2983G>T (nonsense)	posit	MSS	None	5
NC-BC	BC24_31711T	Non-carrier	posit	MSS	N/A	1
	BC23_33198T	Non-carrier	posit	MSS	N/A	1
	BC21_31702T	Non-carrier	posit	MSS	N/A	5
	BC20_33207T	Non-carrier	posit	MSS	N/A (ds)	306
	BC19_31706T	Non-carrier	posit	MSS	N/A	2
	BC18_33215T	Non-carrier	posit	MSS	N/A	3
	BC16_33205T	Non-carrier	posit	MSS	N/A (ds)	393
	BC43_33196T	Non-carrier	posit	MSS	N/A	5
	BC15_31696T	Non-carrier	posit	MSS	N/A (ds)	161
	BC17_31692T	Non-carrier	posit	MSS	N/A	2

^*L, LOH; s, somatic mutation; ds, double somatic mutation.