Epidemiological evidence points to an increased risk of breast cancer in at
axia telangiectasia (AT) heterozygote women. Previous attempts to screen ea
rly onset or familiar breast cancer patients failed to confirm an associati
on. The issue of AT and late onset sporadic breast cancer remained unresolv
ed. We screened 47 women who developed later onset, sporadic breast cancer
for ataxia telangiectasia mutated (ATM) mutations. No mutations were found.