Table 1.

Association of pathogenic variants with early onset of breast cancer

	Total	BRCA1	BRCA2	TP53*	CHEK2†	PALB2	ATM	BRIP1	RAD50	RECQL
PROCAS controls	1567	2	9	0	6	3	6	2	6	5
%		0.13%	0.57%	0.00%	0.38%	0.19%	0.38%	0.13%	0.38%	0.32%
Breast cancer ≤30 study overall	379/184‡	75	35	22	2	4	2	1	1	1
%		19.79%	9.23%	5.80%	0.53%	2.17%	1.09%	0.54%	0.54%	0.54%
P value		<0.0001	<0.0001	<0.0001	0.6576	0.0032	0.1844	0.2847	0.5409	0.4868
Population based cohort	125/46	23	11	5	0	0	0	1	0	0
%		18.4%	8.8%	4.0%				2.17%
P value		<0.0001	<0.0001	<0.0001				0.0832
Referral to MCGM	254/138	52	24	17	2	4	2	0	1	1
%		20.47%	9.45%	6.69%	0.78%	2.90%	1.45%		0.72%	0.72%
P value		<0.0001	<0.0001	<0.0001	0.1320	0.0012	0.1320		0.4467	0.3978
POSH study	287	32	17	5	3
%		11.15%	5.92%	1.74%	1.05%
P value		<0.0001	<0.0001	<0.0001	0.1508

*TP53 p value is based on population frequency of 1/5000.

†CHEK2 p value is calculated for c.1100delC only.

‡Total of women tested for BRCA1/2, TP53 variants and CHEK2 c.1100delC is 379, total number of women tested for an extended panel of genes is 184.

MCGM, Manchester Centre for Genomic Medicine.