Polymorphisms in PTEN in breast cancer families.

Germline mutations in PTEN are the underlying genetic defect in Cowden disease, which is associated with a lifetime risk of 25-50% of developing breast cancer. To investigate the role of PTEN in inherited breast cancer in the absence of manifestations of Cowden disease, we screened 177 unrelated subjects with breast cancer who also had a family history of breast cancer in at least one relative. We found no disease associated PTEN mutations in this cohort, supporting previous studies suggesting that PTEN mutations do not contribute to inherited susceptibility to breast cancer without associated manifestations of Cowden disease. We did identify an association between a common polymorphism in intron 4 and lower mean age of diagnosis of breast cancer. While preliminary, these findings suggest that further study is warranted to determine whether this allelic variant of PTEN could function as a low penetrance breast cancer susceptibility allele.