Table 2. Detailed characteristics of the 10 women with breast cancer, who were found to be heterozygotes for one of the two ATM gene mutations 7271T>G or IVS10-6T>G.

				Family history of breast cancer (number of affected relatives)
				First-degree relative				Second-degree relative
ATM mutation	Laterality	Age at dxa	Follow-up after dxb (years)	Any	Mother	Sister	Daughter	Any	Maternal grandmother	Paternal grandmother	Maternal aunt	Paternal aunt
7271T>G	Unilateral	41–45	⩽10	0	0	0	0	0	0	0	0	0
IVS10-6T>G	Bilateral	⩽40	>10	1	1	0	0	1	0	0	0	1
	Unilateral	⩽40	>10	0	0	0	0	0	0	0	0	0
	Unilateral	41–45	⩽10	0	0	0	0	0	0	0	0	0
	Unilateral	41–45	>10	2	1	1	0	0	0	0	0	0
	Unilateral	46–50	⩽10	1	1	0	0	0	0	1	0	0
	Unilateral	46–50	⩽10	0	0	0	0	2	0	1	0	1
	Unilateral	46–50	⩽10	0	0	0	0	1	0	0	1	0
	Unilateral	46–50	>10	1	0	1	0	2	0	1	0	1
	Unilateral	46–50	>10	0	0	0	0	0	0	0	0	0

^aAge at diagnosis. For a subject with bilateral breast cancer, this is the age at first diagnosis; the second diagnosis was between 46 and 50 years of age.

^bTime between first primary diagnosis and interview date, range 5.1–16.7 years.