The rs12975333 variant in the miR-125a and breast cancer risk in Germany, Italy, Australia and Spain

The rare variant rs12975333 is a G→T change located at the eighth nucleotide of the mature microRNA-125a (miR-125a). The T allele has been reported to block the processing of pri-miRNA to pre-miRNA precursor and to be extremely rare, being detected only once in a panel of 1200 individuals from diverse ethnic backgrounds assessed by the Centre d'Etude du Polymorphisme Humain.1 A study by Li et al 2 showed the T allele of rs12975333 to be strongly associated with breast cancer risk, with 6 of 72 (8.3%) breast cancer cases from two hospitals in Antwerp, Belgium, being carriers of the T allele and none of 282 controls collected from the general population in the Antwerp area or 587 Caucasian controls collected in the USA.2 The breast cancers were all lymph node negative and received only local treatment (mastectomy or lumpectomy followed by radiation treatment). Genotyping was performed by means of the TaqMan assay, as previously described,1 using whole-genome-amplified DNA obtained from …