PURPOSE: Several common genetic variants (single-nucleotide polymorphisms, SNPs) have been shown to be associated with breast cancer (BC) risk in the general population, and to modify BC risk for BRCA1 and BRCA2 mutation carriers. Co-localization of variable number of tandem repeats (VNTRs) with these BC-associated SNPS has not been comprehensively studied.

METHODS: Cross referencing of genome-wide VNTRs with the known BC genome-wide association studies (GWAS) SNPs significantly associated with increased risk for developing breast cancer was carried out. Analysis was based on the overlap between the VNTRs and 10-kb windows around these BC-susceptibility SNPs.

RESULTS: Cross referencing of the 1.2 million TR with the 161 known BC-associated SNPs in the general population led to 690 matches. Of those, in 17 VNTRs, the SNP was within the VNTR. Analysis restricted to loci known to modify BC penetrance in BRCA1 (n = 31) and BRCA2 (n = 33) mutation carriers led to 139 and 170 co-localization matches, respectively. For these, none of the SNPs were within the VNTR. The distances between the SNPs and the VNTRs were not significantly different from what was expected to occur by chance alone (p = 0.61; p = 0.44; p = 0.25, respectively).

CONCLUSION: There is no evidence that VNTRs co-localize with currently reported SNP tagged BC GWAS loci.