Expanding BRCA1/BRCA2 genomic diversity in the Caribbean: insights from the first national cohort in the Dominican Republic

Despite the rapid expansion of hereditary cancer testing worldwide, Caribbean populations remain underrepresented in BRCA reference datasets, limiting accurate variant interpretation and equitable implementation of precision medicine. This study expands genomic representation in the Caribbean by characterizing the germline BRCA1/BRCA2 variant spectrum in the first national cohort from the Dominican Republic. We retrospectively analyzed 648 consecutively referred individuals using next-generation sequencing. Variants were classified according to ACMG/AMP recommendations and findings were contextualized with published Caribbean, Latin American, and African-ancestry data. Twenty-seven individuals (4.2%) carried pathogenic or likely pathogenic BRCA variants representing 15 distinct variants. BRCA2 variants predominated. Comparison with published datasets showed partial overlap with neighboring populations while highlighting a distinctive Caribbean variant spectrum. Recurrent variants were identified; however, the available data are insufficient to infer a founder effect. This study expands BRCA1/BRCA2 genomic diversity data from the Caribbean by providing the first national reference dataset from the Dominican Republic. The findings support improved variant interpretation, genetic counseling, and precision medicine while contributing to better genomic representation of Caribbean populations.