Rs7158782

rs7158782 is one of 4 SNPs found on chromosome 14 near a gene known as T-cell leukemia/lymphoma 1A (TCL1A). This gene appears to be estrogen dependent.

In a study of ~300 patients with early-stage estrogen receptor–positive (ER+) breast cancer who were treated with the aromatase inhibitor (AI) anastrozole or exemestane and who developed musculoskeletal toxicity severe enough to prompt discontinuation, rs7158782(G) allele carriers were at ~2x higher risk for toxicity (CI: 1.5 - 2.9, p < 10e-6). The population attributable risk (i.e., the fraction of such adverse events that could be due to this allele) was estimated to be 11%.

An editorial accompanying this article downplays the clinical utility of this finding, since testing for this allele, given its frequency and (mere) doubling of risk, has about equal odds of yielding a true positive and a false positive.