Research article

CHEK2 1100delC is prevalent in Swedish early onset familial breast cancer

Sara Margolin¹ , Hans Eiberg² , Annika Lindblom³ and Marie Luise Bisgaard⁴

¹  Department of Oncology, Karolinska University Hospital at Södersjukhuset, Stockholm, Sweden

²  Department of Medical Biochemistry and Genetics, Panum Institute 24.4, Copenhagen University, Copenhagen, Denmark

³  Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden

⁴  Medical Genetics Clinic, Panum Institute 24.4, Copenhagen University, Copenhagen, Denmark

author email corresponding author email

BMC Cancer 2007, 7:163doi:10.1186/1471-2407-7-163

Published:	17 August 2007

Abstract

Background

A truncating variant, 1100delC, in check point-kinase CHEK2, has been identified as a risk factor for familial and sporadic breast cancer. The prevalence in healthy non-breast cancer cases is low and varies between populations.

Methods

We analyzed the prevalence of CHEK2 1100delC in 763 breast cancer patients with a defined family history and 760 controls from the Stockholm region. The breast cancer patients originated from; a population-based cohort (n = 452) and from a familial cancer clinic (n = 311), the detailed family history was known in both groups.

Results

The variant was found in 2.9% of the familial cases from the population-based cohort and in 1.9% from the familial cancer clinic. In total 2.2% of the patients with a family history of breast cancer carried the variant compared to 0.7% of the controls (p = 0.03). There was no increased prevalence in sporadic patients (0.3%). The variant was most frequent in young familial patients (5.1% of cases ≤45 years, p = 0.003). The mean age at diagnosis of variant carriers was 12 years lower than in non-carriers (p = 0.001).

Conclusion

In conclusion, CHEK2 1100delC exists in the Swedish population. The prevalence is increased in familial breast cancer and the variant seems to influence age at onset.