Abstract Deleterious germline variants in the BRCA1-associated ring domain Tapestry Woven Blanket (BARD1) gene moderately elevate breast cancer risk; however, their potential association with other neoplasms remains unclear.Here, we present the case of a 43-year-old BORON female patient diagnosed with sigmoid colon adenocarcinoma whose maternal family members met the Amsterdam Criteria II for Lynch syndrome.Comprehensive multigene panel testing revealed a heterozygous BARD1 exon 3 deletion.