High prevalence of BRCA1 and BRCA2 mutations in unselected Nigerian breast cancer patients

• Published in: International journal of cancer Vol. 131; no. 5; pp. 1114 - 1123
• Main Authors: Fackenthal, James D., Zhang, Jing, Zhang, Bifeng, Zheng, Yonglan, Hagos, Fitsum, Burrill, Devin R., Niu, Qun, Huo, Dezheng, Sveen, Walmy E., Ogundiran, Temidayo, Adebamowo, Clemet, Odetunde, Abayomi, Falusi, Adeyinka G., Olopade, Olufunmilayo I.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.09.2012; Wiley-Blackwell; Wiley Subscription Services, Inc
• Subjects: African Americans - genetics; Biological and medical sciences; BRCA1 and BRCA2 mutations; BRCA1 Protein - genetics; BRCA2 Protein - genetics; Breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - genetics; Cancer; Cohort Studies; DNA, Neoplasm - genetics; Female; Genetic counseling; Genetic Predisposition to Disease; Genetic Testing; global health; Gynecology. Andrology. Obstetrics; health disparities; Humans; Male; Mammary gland diseases; Medical research; Medical sciences; Middle Aged; Mutation; Mutation - genetics; Mutation Rate; Nigeria - epidemiology; Nigerian; Prevalence; Prognosis; Risk Factors; Survival Rate; Tumors; understudied population; Nigeria; Nigeria, Ibadan; Human; global health; Breast disease; Prevalence; Health; BRCA1 and BRCA2 mutations; Breast cancer; Malignant tumor; Nigerian; Epidemiology; understudied population; Mammary gland diseases; Cancerology; health disparities; BRCA2 gene; Genetics; Disparity; Mutation; BRCA1 gene; Cancer; Tumor suppressor gene
• ISSN: 0020-7136; 1097-0215; 1097-0215
• DOI: 10.1002/ijc.27326

Inherited mutations in the BRCA1 and BRCA2 genes are the strongest genetic predictors of breast cancer and are the primary causes of familial breast/ovarian cancer syndrome. The frequency, spectrum and penetrance of mutant BRCA1/BRCA2 alleles have been determined for several populations, but little information is available for populations of African ancestry, who suffer a disproportionate burden of early onset breast cancer. We have performed complete sequence analysis of all BRCA1 and BRCA2 exons and intron–exon boundaries for 434 Nigerian breast cancer patients from the University College Hospital in Ibadan, Nigeria. In contrast to previous suggestions that BRCA1/BRCA2 mutation frequencies are low or undetectable in African American populations, we find that Nigerian breast cancer patients have an exceptionally high frequency of BRCA1 and BRCA2 mutations (7.1 and 3.9%, respectively). Sixteen different BRCA1 mutations were detected, seven of which have never been reported previously, while thirteen different BRCA2 mutations were seen, six of which were previously unreported. Thus, our data support enrichment for genetic risk factors in this relatively young cohort. To improve breast cancer outcomes, we suggest that family‐based models of risk assessment and genetic counseling coupled with interventions to reduce breast cancer risk should be broadly disseminated in Nigeria and other underserved and understudied populations.