Transethnic and race-stratified genome-wide association study of fibroid characteristics in African American and European American women.

OBJECTIVE: To identify, through genome-wide association studies, genetic loci that associate with differences in fibroid size and number in a population of African American and European American women.
DESIGN: Cross-sectional study.
SETTING: Not applicable. PATIENT(S): Using BioVU, a clinical population from the Vanderbilt University Medical Center, and the Coronary Artery Risk Development in Young Adults cohort, a prospective cohort, we identified 1520 women (609 African American and 911 European American) with documented fibroid characteristics. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Outcome measurements include volume of largest fibroid, largest fibroid dimension, and number of fibroids (single vs. multiple). RESULT(S): In race-stratified analyses we achieved genome-wide significance at a variant located between MAT2B and TENM2 (rs57542984, β = 0.13; 95% confidence interval 0.09, 0.17) for analyses of largest fibroid dimension in African Americans. The strongest signal for transethnic analyses was at a variant on 1q31.1 located between PLA2G4A and BRINP3 (rs6605005, β = 0.24; 95% confidence interval 0.15, 0.33) for fibroid volume. Results from MetaXcan identified an association between predicted expression of the gene ER degradation enhancing alpha-mannosidase like protein 2 (EDEM2) in the thyroid and number of fibroids (Z score = -4.51). CONCLUSION(S): This study identified many novel associations between genetic loci and fibroid size and number in both race-stratified and transethnic analyses. Future studies are necessary to further validate our study findings and to better understand the mechanisms underlying these associations.