BRCA1 and breast carcinoma: By sequencing 27 exonic regions of BRCA1 and 2, four germline variants in exon 9 of BRCA1 were observed in 3/9 affected cats, and it was proposed that the germline genetic variants present in one-third of mammary carcinoma-bearing cats may be linked to an elevated risk of hereditary mammary carcinogenesis [246].