Background: Germine mutations in BRCA1 and BRCA2 genes account for only 20-40% of familial breast cancer cases. The CHEK2 gene encodes a checkpoint kinase, involved in response to DNA damage, and hence is a candidate gene for breast cancer susceptibility. Indeed, the CHEK21100delC truncating mutation was reported in a subset of mostly North European breast cancer families. The rate of the CHEK21100deiC variant in the Ashkenazi Jewish population was reported to be 0.3%. Objectives: To evaluate whether CHEK2 germline mutations contribute to a breast cancer predisposition in Ashkenazi** Jewish high risk families. Methods: High risk Ashkenazi Jewish women, none of whom was a carrier of the predominant Jewish mutations in BRCA1/BRCA2, were genotyped for germline mutations in the CHEK2 gene by exon-specific polymerase chain reaction followed by denaturing gradient gel electrophoresis and sequencing of abnormally migrating fragments. Results: Overall, 172 high risk women were genotyped: 75 (43.6%) with breast cancer (average age at diagnosis 49.6 ± 9.6 years, mean SD) and 97 asymptornatic individuals (age at counseling 48.3 8.2 years). No truncating mutations were noted and four previously described missense mutations were detected (R3W 1.2%, 1157T 1.2%, R180C 0.6% and S428F 5%), one silent polymorphism (E84E 20.5%) and one novel missense mutation (Y424 1.2%). Segregation analysis of the 1157T and S428F mutations (shown to affect protein function) with the cancer phenotype showed concordance for the CHK2Ι157T mutation, as did two of three families with the CHK2S428F mutation. Conclusions: CHEK2 missense mutations may contribute to breast cancer susceptibility in Ashkenazi Jews.
|Number of pages||6|
|Journal||Israel Medical Association Journal|
|State||Published - Nov 2007|
- Ashkenazi lews
- Denaturing gradient gel electrophoresis
- Germline mutations