A whole-genome investigation in Brazilian early-onset and FH(+) breast cancer patients detected rare germline CNVs [25]; one of the reported patients and her affected sister carried a 540 kb 1p31.1 microdeletion encompassing only 3 genes (ST6GALNAC3, ST6GALNAC5, PIGK); both patients were included in the present study. This evidence concerns the gene PIGK and breast cancer.