Hirachan, Suzita

Objective Breast cancer (BC) is the most common form of cancer among Asian females. Mutations in the BRCA1/ BRCA2 genes are often observed in BC cases and largely increase 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 these mutations among South Asian countries. Methods A systematic literature search was performed for the BRCA1 and BRCA2 gene mutation spectrum using electronic databases such as PubMed, EMBASE, and Google Scholar. Twenty studies were selected based on specific inclusion and exclusion criteria. Results The 185delAG (c.68_69del) mutation in exon 2 of BRCA1 was the most common recurrent mutation and founder mutation found. Various intronic variants, variants of unknown significance, large genomic rearrangements, and polymorphisms were also described in some studies. Conclusions The South Asian population has a wide variety of genetic mutations of BRCA1 and BRCA2 that differ according to countries and ethnicities. A stronger knowledge of various population-specific mutations in these cancer susceptibility genes can help provide efficient strategies for genetic testing.

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.