THE FREQUENCY OF POLYMORPHISMSOF THE GENE 5382insC BRCA1 IN PATIENTSWITH FAMILIAL BREAST CANCERS ARE EXPOSEDTO IONIZING RADIATION AS A RESULTOF SEMIPALATINSK NUCLEAR TEST SITEAND THEIR DESCENDANTS

Abstract

Genetic changes play an important role among the risk factors for breast cancer, but their
mechanisms of and contribution to the development of the disease is not finalized.
Purpose of the study: determining the frequency of the BRCA1 gene polymorphism 5382insC in
patients with familial breast cancers in the region radiological trouble Semipalatinsk nuclear test site in
the first and second generations of irradiated.
Materials and methods: The study included 250 women aged 40 to 79 years, Kazakh nationality,
including 190 breast cancer patients, distributed in groups. The first group included 60 patients with a
family history, exposed to direct radiation and their descendants. The second group included 65 patients
with a family history without radiological, in the third - 65 patients without a family history and
radiological. Patients and women in the control group were assigned depending on the availability of
direct irradiation (the first group) and age (older and younger than 50 years old) - in the other. Studied
the frequency of BRCA1 gene polymorphism 5382insC. For statistical analysis of the frequency
difference using one-sided Fisher's exact test. The boundary significance level to disprove the null
hypothesis accepted p <0,05.
Results: The frequency of the studied polymorphism was higher in the total group of breast cancer
patients with a family history of radioecological and where it was 20%, whereas in the absence of
radiological history - 7.7%, family history and radiological - 6.2%, while in the control group - 3.3% (p =
0.038, p = 0.019, p = 0.004, respectively). The allocation to the directly irradiated and children, and by
age, statistically significant differences were not obtained.
Conclusions:
There are differences in the frequency of the BRCA1 gene polymorphism 5382insC in women with
breast cancer in indigenous population of East Kazakhstan, due to the presence of family history and
radiological.
Registered significant excess frequency of this polymorphism in patients with the presence of family
and radiological history of the control group and female patients with breast cancer with a family history
without radiological and without family and radiological history, indicating that the leading role of the
radiation factor in the accumulation of 5382insC BRCA1 gene mutations in the population.