Follow-up to genome-wide linkage and admixture mapping studies implicates components of the extracellular matrix in susceptibility to and size of uterine fibroids

The Effect of Race/Ethnicity and MED12 Mutation on the Expression of Long Non-Coding RNAs in Uterine Leiomyoma and Myometrium

The objective of this study was to elucidate the expression of long non-coding RNA (lncRNA) in leiomyomas (Lyo) and paired myometrium (Myo) and explore the impact of race and MED12 mutation. Fold change analysis (Lyo/paired Myo) indicated the expression of 63 lncRNAs was significantly altered in the mutated group but not in the non-mutated Lyo. Additionally, 65 lncRNAs exhibited an over 1.5-fold change in the Black but not the White group. Fifteen differentially expressed lncRNAs identified with next-generation sequencing underwent qRT-PCR confirmation. Compared with Myo, the expression of TPTEP1, PART1, RPS10P7, MSC-AS1, SNHG12, CA3-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was significantly higher, while the expression of ZEB2-AS1, LINC00957, and LINC01186 was significantly lower. Comparison of normal Myo with diseased Myo showed significant differences in the expression of several lncRNAs. Analysis based on race and Lyo MED12 mutation status indicated a significantly higher expression of RPS10P7, SNHG12, LINC01449, LINC02433, and LINC02624 in Lyo from Black patients. The expression of TPTEP1, PART1, RPS10P7, MSC-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was higher, while LINC01186 was significantly lower in the MED12-mutated group. These results indicate that Lyo are characterized by aberrant lncRNA expression, which is further impacted by race and Lyo MED12 mutation status.

The role of long non-coding RNA H19 in infertility

Infertility is defined as the failure to conceive after at least one year of unprotected intercourse. Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides but do not convert into proteins. LncRNAs, particularly lncRNA H19, have been linked to the emergence and progression of various diseases. This review focuses on the role of H19 in infertility caused by polycystic ovary syndrome, endometriosis, uterine fibroids, diminished ovarian reserve, male factor, and assisted reproductive technology-related pathology, highlighting the potential of H19 as a molecular target for the future treatment of infertility.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

Exploring Potential Causal Genes for Uterine Leiomyomas: A Summary Data-Based Mendelian Randomization and FUMA Analysis

Objective: To explore potential causal genetic variants and genes underlying the pathogenesis of uterine leiomyomas (ULs).

Methods: We conducted the summary data-based Mendelian randomization (SMR) analyses and performed functional mapping and annotation using FUMA to examine genetic variants and genes that are potentially involved in the pathogenies of ULs. Both analyses used summarized data of a recent genome-wide association study (GWAS) on ULs, which has a total sample size of 244,324 (20,406 cases and 223,918 controls). We performed separate SMR analysis using CAGE and GTEx eQTL data.

Results: Using the CAGE eQTL data, our SMR analysis identified 13 probes tagging 10 unique genes that were pleiotropically/potentially causally associated with ULs, with the top three probes being ILMN_1675156 (tagging CDC42, PSMR = 8.03 × 10⁻⁹), ILMN_1705330 (tagging CDC42, PSMR = 1.02 × 10⁻⁷) and ILMN_2343048 (tagging ABCB9, PSMR = 9.37 × 10⁻⁷). Using GTEx eQTL data, our SMR analysis did not identify any significant genes after correction for multiple testing. FUMA analysis identified 106 independent SNPs, 24 genomic loci and 137 genes that are potentially involved in the pathogenesis of ULs, seven of which were also identified by the SMR analysis.

Conclusions: We identified many genetic variants, genes, and genomic loci that are potentially involved in the pathogenesis of ULs. More studies are needed to explore the exact underlying mechanisms in the etiology of ULs.

GRAF2, WDR44, and MICAL1 mediate Rab8/10/11-dependent export of E-cadherin, MMP14, and CFTR ΔF508

In addition to the classical pathway of secretion, some transmembrane proteins reach the plasma membrane through alternative routes. Several proteins transit through endosomes and are exported in a Rab8-, Rab10-, and/or Rab11-dependent manner. GRAFs are membrane-binding proteins associated with tubules and vesicles. We found extensive colocalization of GRAF1b/2 with Rab8a/b and partial with Rab10. We identified MICAL1 and WDR44 as direct GRAF-binding partners. MICAL1 links GRAF1b/2 to Rab8a/b and Rab10, and WDR44 binds Rab11. Endogenous WDR44 labels a subset of tubular endosomes, which are closely aligned with the ER via binding to VAPA/B. With its BAR domain, GRAF2 can tubulate membranes, and in its absence WDR44 tubules are not observed. We show that GRAF2 and WDR44 are essential for the export of neosynthesized E-cadherin, MMP14, and CFTR ΔF508, three proteins whose exocytosis is sensitive to ER stress. Overexpression of dominant negative mutants of GRAF1/2, WDR44, and MICAL1 also interferes with it, facilitating future studies of Rab8/10/11-dependent exocytic pathways of central importance in biology.

A Trans-Ethnic Genome-Wide Association Study of Uterine Fibroids

Uterine fibroids affect up to 77% of women by menopause and account for up to $34 billion in healthcare costs each year. Although fibroid risk is heritable, genetic risk for fibroids is not well understood. We conducted a two-stage case-control meta-analysis of genetic variants in European and African ancestry women with and without fibroids classified by a previously published algorithm requiring pelvic imaging or confirmed diagnosis. Women from seven electronic Medical Records and Genomics (eMERGE) network sites (3,704 imaging-confirmed cases and 5,591 imaging-confirmed controls) and women of African and European ancestry from UK Biobank (UKB, 5,772 cases and 61,457 controls) were included in the discovery genome-wide association study (GWAS) meta-analysis. Variants showing evidence of association in Stage I GWAS (P < 1 × 10^-5) were targeted in an independent replication sample of African and European ancestry individuals from the UKB (Stage II) (12,358 cases and 138,477 controls). Logistic regression models were fit with genetic markers imputed to a 1000 Genomes reference and adjusted for principal components for each race- and site-specific dataset, followed by fixed-effects meta-analysis. Final analysis with 21,804 cases and 205,525 controls identified 326 genome-wide significant variants in 11 loci, with three novel loci at chromosome 1q24 (sentinel-SNP rs14361789; P = 4.7 × 10^-8), chromosome 16q12.1 (sentinel-SNP rs4785384; P = 1.5 × 10^-9) and chromosome 20q13.1 (sentinel-SNP rs6094982; P = 2.6 × 10^-8). Our statistically significant findings further support previously reported loci including SNPs near WT1, TNRC6B, SYNE1, BET1L, and CDC42/WNT4. We report evidence of ancestry-specific findings for sentinel-SNP rs10917151 in the CDC42/WNT4 locus (P = 1.76 × 10^-24). Ancestry-specific effect-estimates for rs10917151 were in opposite directions (P-Het-between-groups = 0.04) for predominantly African (OR = 0.84) and predominantly European women (OR = 1.16). Genetically-predicted gene expression of several genes including LUZP1 in vagina (P = 4.6 × 10^-8), OBFC1 in esophageal mucosa (P = 8.7 × 10^-8), NUDT13 in multiple tissues including subcutaneous adipose tissue (P = 3.3 × 10^-6), and HEATR3 in skeletal muscle tissue (P = 5.8 × 10^-6) were associated with fibroids. The finding for HEATR3 was supported by SNP-based summary Mendelian randomization analysis. Our study suggests that fibroid risk variants act through regulatory mechanisms affecting gene expression and are comprised of alleles that are both ancestry-specific and shared across continental ancestries.

H19 lncRNA identified as a master regulator of genes that drive uterine leiomyomas

Uterine leiomyomas or fibroids (UFs) are benign tumors characterized by hyperplastic smooth muscle cells and excessive deposition of extracellular matrix (ECM). Afflicting ~80% of women, and symptomatic in 25%, UFs bring tremendous suffering and are an economic burden worldwide; they cause severe pain and bleeding, and are the leading cause of hysterectomy. Yet, UFs are severely understudied with few effective treatment options available; those that are available frequently have significant side effects such as menopausal symptoms. Recently, integrated genome-scale studies have revealed mutations and fibroid subtype-specific expression changes in key driver genes, with MED12 and HMGA2 together contributing to nearly 90% of all UFs, but their regulation of expression is poorly characterized. Here we report that the expression of H19 long noncoding RNA (lncRNA) is aberrantly increased in UFs. Using cell culture and genome-wide transcriptome and methylation profiling analyses, we demonstrate that H19 promotes expression of MED12, HMGA2, and key ECM-remodeling genes via multiple mechanisms including a new class of epigenetic modification by TET3. Our results mark the first example of an evolutionarily conserved lncRNA in pathogenesis of UFs and regulation of TET expression. Given the link between a H19 single-nucleotide polymorphism (SNP) and increased risk and tumor size of UFs, and the existence of multiple fibroid subtypes driven by key pathway genes regulated by H19, we propose a unifying mechanism for pathogenesis of uterine fibroids mediated by H19 and identify a pathway for future exploration of novel target therapies for uterine leiomyomas.

α-1,2-Mannosidase MAN1C1 Inhibits Proliferation and Invasion of Clear Cell Renal Cell Carcinoma

Background: This study investigated the biological function of the gene MAN1C1 α-mannosidase in renal cell carcinoma. It has been reported that MAN1C1 is probably a potential tumor suppressor gene in Wilms. However, the role of MAN1C1 in human clear cell renal cell carcinoma (ccRCC) has not been reported.

Methods: In this study, MAN1C1 gene over-expression was used to transfect human renal cancer cell lines 786-O and OS-RC-2 to study apoptosis and the underlying mechanisms which influence epithelial-mesenchymal transition.

Results: MAN1C1 was down-regulated in ccRCC and related to the clinicopathological factors and prognosis of ccRCC. We revealed that over-expression MAN1C1 showed anti-tumor effect by inducing apoptosis, as determined by Cell Counting Kit-8 (CCK-8) assay, cell cycle analysis, and western blot analysis. What's more, MAN1C1 over-expression remarkably increased the ratio of Bax/Bcl-2 and inhibited epithelial-mesenchymal transition by increasing the expression of E-CA. In addition, the ratio of Bax/Bcl-2 and E-CA were also increased in MAN1C1 gene over-expression renal cancer cells compared with the control cells.

Conclusion: We find that re-expression of silenced MAN1C1 in ccRCC cell lines inhibited cell viability, colony formation, induced apoptosis, suppressed cell invasion and migration. In conclusion, MAN1C1 is a novel functional tumor suppressor in renal carcinogenesis. This is the first time that the function of MAN1C1 gene has been verified in the renal tumor tissue so far.

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.

Factors affecting the loss of MED12-mutated leiomyoma cells during in vitro growth

Uterine leiomyomas (UL) are the most prevalent symptomatic human tumors at all and somatic mutations of the gene encoding mediator subcomplex 12 (MED12) constitute the most frequent driver mutations in UL. Recently, a rapid loss of mutated cells during in vitro growth of UL-derived cell cultures was reported, resulting in doubts about the benefits of UL-derived cell cultures. To evaluate if the rapid loss of MED12-mutated cells in UL cell cultures depends on in vitro passaging, we set up cell cultures from nine UL from 40–50 year old Caucasian patients with at least one UL. Cultured UL cells were investigated for loss of MED12-mutated cells. Genetic characterization of native tumor samples and adjacent myometrium was done by array analysis. “Aged” primary cultures without passaging were compared to cells of three subsequent passages. Comparative analyses of the mutated/non-mutated ratios between native tissue, primary cells, and cultured tumor cells revealed a clear decrease of MED12-mutated cells. None of the tumors showed gross alterations of the array profiles, excluding the presence of gross genomic imbalances besides the MED12 mutations as a reason for the intertumoral variation in the loss of MED12-mutated cells. Albeit at a lesser rate, loss of MED12-mutated cells from cell cultures of UL occurs even without passaging thus indicating the requirement of soluble factors or matrix components lacking in vitro. Identification of these factors can help to understand the mechanisms of the growth of the most frequent type of uterine leiomyomas and to decipher novel drug targets.

Admixture mapping of uterine fibroid size and number in African American women

OBJECTIVE

To evaluate the relationship between genetic ancestry and uterine fibroid characteristics.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

A total of 609 African American participants with image- or surgery-confirmed fibroids in a biorepository at Vanderbilt University electronic health record biorepository and the Coronary Artery Risk Development in Young Adults studies were included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Outcome measures include fibroid number (single vs. multiple), volume of largest fibroid, and largest fibroid dimension of all fibroid measurements.

RESULT(S)

Global ancestry meta-analyses revealed a significant inverse association between percentage of European ancestry and risk of multiple fibroids (odds ratio: 0.78; 95% confidence interval 0.66, 0.93; P=6.05 × 10-3). Local ancestry meta-analyses revealed five suggestive (P<4.80 × 10-3) admixture mapping peaks in 2q14.3-2q21.1, 3p14.2-3p14.1, 7q32.2-7q33, 10q21.1, 14q24.2-14q24.3, for number of fibroids and one suggestive admixture mapping peak (P<1.97 × 10-3) in 10q24.1-10q24.32 for volume of largest fibroid. Single variant association meta-analyses of the strongest associated region from admixture mapping of fibroid number (10q21.1) revealed a strong association at single nucleotide polymorphism variant rs12219990 (odds ratio: 0.41; 95% confidence interval 0.28, 0.60; P=3.82 × 10-6) that was significant after correction for multiple testing.

CONCLUSION(S)

Increasing African ancestry is associated with multiple fibroids but not with fibroid size. Local ancestry analyses identified several novel genomic regions not previously associated with fibroid number and increasing volume. Future studies are needed to explore the genetic impact that ancestry plays into the development of fibroid characteristics.

A multi-stage genome-wide association study of uterine fibroids in African Americans

Uterine fibroids are benign tumors of the uterus affecting up to 77% of women by menopause. They are the leading indication for hysterectomy, and account for $34 billion annually in the United States. Race/ethnicity and age are the strongest known risk factors. African American (AA) women have higher prevalence, earlier onset, and larger and more numerous fibroids than European American women. We conducted a multi-stage genome-wide association study (GWAS) of fibroid risk among AA women followed by in silico genetically predicted gene expression profiling of top hits. In Stage 1, cases and controls were confirmed by pelvic imaging, genotyped and imputed to 1000 Genomes. Stage 2 used self-reported fibroid and GWAS data from 23andMe, Inc. and the Black Women's Health Study. Associations with fibroid risk were modeled using logistic regression adjusted for principal components, followed by meta-analysis of results. We observed a significant association among 3399 AA cases and 4764 AA controls at rs739187 (risk-allele frequency = 0.27) in CYTH4 (OR (95% confidence interval) = 1.23 (1.16-1.30), p value = 7.82 × 10-9). Evaluation of the genetic association results with MetaXcan identified lower predicted gene expression of CYTH4 in thyroid tissue as significantly associated with fibroid risk (p value = 5.86 × 10-8). In this first multi-stage GWAS for fibroids among AA women, we identified a novel risk locus for fibroids within CYTH4 that impacts gene expression in thyroid and has potential biological relevance for fibroids.

G-protein-coupled estrogen receptor-30 gene polymorphisms are associated with uterine leiomyoma risk

The G-protein-coupled estrogen receptor (GPR30, GPER-1) is a member of the G-protein-coupled receptor 1 family and is expressed significantly in uterine leiomyomas. To understand the relationship between GPR30 single nucleotide polymorphisms and the risk of leiomyoma, we measured the follicle-stimulating hormone (FSH) and estradiol (E2) levels of 78 perimenopausal healthy women and 111 perimenopausal women with leiomyomas. The participants' leiomyoma number and volume were recorded. DNA was extracted from whole blood with a GeneJET Genomic DNA Purification Kit. An amplification-refractory mutation system polymerase chain reaction approach was used for genotyping of the GPR30 gene (rs3808350, rs3808351, and rs11544331). The differences in genotype and allele frequencies between the leiomyoma and control groups were calculated using the chi-square (χ2) and Fischer's exact test. The median FSH level was higher in controls (63 vs. 10 IU/L, p=0.000), whereas the median E2 level was higher in the leiomyoma group (84 vs. 9.1 pg/mL, p=0.000). The G allele of rs3808351 and the GG genotype of both the rs3808350 and rs3808351 polymorphisms and the GGC haplotype increased the risk of developing leiomyoma. There was no significant difference in genotype frequencies or leiomyoma volume. However, the GG genotype of the GPR30 rs3808351 polymorphism and G allele of the GPR30 rs3808351 polymorphism were associated with the risk of having a single leiomyoma. Our results suggest that the presence of the GG genotype of the GPR30 rs3808351 polymorphism and the G allele of the GPR30 rs3808351 polymorphism affect the characteristics and development of leiomyomas in the Turkish population.

Genetic determinants of uterine fibroid size in the multiethnic NIEHS uterine fibroid study

We conducted a follow-up association study across extended candidate chromosomal regions for uterine leiomyoma (UL), or fibroids, to search for loci influencing the size of UL in 916 premenopausal North American women participants to the NIEHS uterine fibroid study. Proportional odds models with adjustments for confounders were fitted to evaluate the association of a final set of 2,484 single nucleotide polymorphisms (SNPs) with the size of uterine fibroids measured by transabdominal and transvaginal ultrasounds. SNP association with UL size was tested in a case-only design comparing three categories of tumor size (small, medium and large tumors) and in a design that included UL-free controls as the lowest category of a four-level ordinal outcome to account for misclassifications due to small, undetected tumors. In the case-only design, rs2285789 in SORCS2 (sortilin-related VPS10 domain containing receptor 2) was the sole variant that remained significant after correction for multiple testing (Bonferroni-adjusted P=0.037). Several other SNPs, namely those located in MYT1L, TMCC1 and BRCA1, reached promising associations. In the design that included the controls, several genes of potential relevance to UL pathogenesis were associated (Bonferroni-unadjusted P < 0.01) with tumor size, particularly LIFR-AS1 (leukemia inhibitory factor receptor alpha-antisense RNA 1), which showed the strongest association (Bonferroni-unadjusted P=0.0006) among the genes with regulated expression in UL. In conclusion, SORCS2, a known GWAS candidate for circulating IGF-I and IGFBP-3, may act through IGF-I signaling to affect the size of fibroids. Through down-regulation of LIFR, LIFR-AS1 may mediate the inhibitory action of LIF (leukemia inhibitory factor), a cytokine involved in embryonic uterine development. Replication analyses are needed to substantiate our reported associations of SORCS2 and LIFR-AS1 with the size of fibroids.

Fine mapping of the uterine leiomyoma locus on 1q43 close to a lncRNA in the RGS7-FH interval

Mutations in fumarate hydratase (FH) on chromosome 1q43 cause a rare cancer syndrome, hereditary leiomyomatosis and renal cell cancer (HLRCC), but are rare in nonsyndromic and common uterine leiomyoma (UL) or fibroids. Studies suggested that variants in FH or in a linked gene may also predispose to UL. We re-sequenced 2.3 Mb of DNA spanning FH in 96 UL cases and controls from the multiethnic NIEHS-uterine fibroid study, and in 18 HLRCC-associated UL probands from European families then selected 221 informative SNPs for follow-up genotyping. We report promising susceptibility associations with UL peaking at rs78220092 (P=7.0×10(-5)) in the RGS7-FH interval in African Americans. In race-combined analyses and in meta-analyses (n=916), we identified promising associations with risk peaking upstream of a non-protein coding RNA (lncRNA) locus located in the RGS7-FH interval closer to RGS7, and associations with tumor size peaking in the distal phospholipase D family, member 5 (PLD5) gene at rs2654879 (P=1.7×10(-4)). We corroborated previously reported FH mutations in nine out of the 18 HLRCC-associated UL cases and identified two missense mutations in FH in only two nonsyndromic UL cases and one control. Our fine association mapping and integration of existing gene profiling data showing upregulated expression of the lncRNA and downregulation of PLD5 in fibroids, as compared to matched myometrium, suggest a potential role of this genomic region in UL pathogenesis. While the identified variations at 1q43 represent a potential risk locus for UL, future replication analyses are required to substantiate our observation.

Evaluation of GWAS candidate susceptibility loci for uterine leiomyoma in the multi-ethnic NIEHS uterine fibroid study

We evaluated the association of 56 candidate SNPs identified in two published genome-wide association studies (GWAS) of uterine leiomyoma (UL), or fibroids, with the risk and tumor size in the multi-ethnic uterine fibroid study (NIEHS-UFS). The selected SNPs were genotyped in 916 premenopausal women of African American (AA) and European American (EA) descents and their association with the outcomes was evaluated in race-stratified models and in meta-analysis of risk in NIEHS-UFS and discovery and replication GWAS in the Japanese population. We report moderate associations of variant rs4954368 in THSD7B (thrombospondin, type I, domain containing 7B) with tumor size in pooled analysis of AA and EA samples (P = 0.004), and at TNRC6B (trinucleotide repeat containing 6B) variants rs138039 and rs139909 in EA (P = 0.001 and 0.008, respectively). The most significant associations with risk in meta-analysis were observed at TNRC6B variants rs739182 (P = 3.7 × 10(-10)) and rs2072858 (P = 1.1 × 10(-9)) and were stronger than those reported in the discovery GWAS (P = 2.01 × 10(-8) and 2.58 × 10(-8), respectively). The present study failed to replicate the associations reported for CCDC57 and FASN in a discovery GWAS in populations of European descent. Consistent with previous replication studies in the Right From the Start Study (RFTS) and the BioVU DNA repository, we provide independent evidence for association of TNRC6B with both risk and size of UL. The present study is the first to report a replicated association of THSD7B with UL, albeit with tumor size and not with risk.

Admixture mapping of genetic variants for uterine fibroids

Uterine leiomyoma (UL) are benign neoplasms arising from the smooth muscle cells of the uterus. One of the established risk factors for UL is African American ethnicity. Studies have consistently shown that African Americans have 2-3 times higher risk compared with that of non-Hispanic Whites. However, there is still no adequate explanation for the higher risk among African Americans. To investigate the genetic contribution to the observed difference between the African American and European American populations, we conducted an admixture scan in 525 eligible African American women participants to the NIEHS uterine fibroid study (NIEHS-UFS). In models with no stratification, we found multiple genomic regions showing significant and suggestive evidence of association, with chromosomal band 2q32.2 at rs256552 showing the highest score (Z-score = 7.86, Bonferroni adjusted p-value = 5.5×10^-12) consistent with the suggestive evidence reported for this genomic region in the Black Women's Health Study. However, in models stratified by the body mass index (BMI) covariate, chromosomal 1q42.2 was the sole genomic region that consistently showed suggestive associations across the BMI categories tested (Z-scores ≤ -3.96, Bonferroni adjusted p-values ≤ 0.107). In age-stratified models, a significant association was observed in the older category (age > 40) reaching a Z-score of 6.44 (Bonferroni-adjusted p-value = 1.64 × 10^-7) at rs256552. The mean percentage of European ancestry among cases was lower than that among controls in the NIEHS-UFS study. However, our study did not show a significant association between mean percentage of European ancestry and UL.