BRCA 1/2 Mutation Spectrum Analysis in South Asia: A Systematic Review

Abstract

Background: Breast cancer (BC) is the most common form of all cancers among Asian females. Mutations in BRCA1/BRCA2 gene are observed in BC cases and also largely increases the lifetime risk of having BC. Because of the paucity of high-quality data on the molecular spectrum of BRCA mutations in South Asian populations, we aimed to explore the spectrum of BRCA gene mutation among the South Asian Population.Methods: A systematic literature search of electronic databases like PubMed, EMBASE, and Google Scholar on BRCA1 and BRCA2 gene mutation spectrum was carried out for peer-reviewed articles providing information on the spectrum of either BRCA1 or BRCA2 gene mutation on South Asian women with any form of breast cancer.Results: Twenty studies were selected for review from four South Asian countries showing similar BRCA1/2 gene mutation patterns. 185delAG mutation in exon 2 in BRCA1 was the most common recurrent mutation and founder mutation found. Various intronic variants, variants of unknown significance, large genomic rearrangements (LGRs) and polymorphisms are also described in some studies. Conclusions: The prevalence of BRCA1 mutations is higher than BRCA2 mutations in the South Asian population with a wide variation among different countries and ethnicities. The knowledge of various population-specific mutations in these cancer susceptibility genes can help provide efficient strategies for genetic testing.