Uterine Fibroid Susceptibility and Your Genetics

Written by Scott Peeples, BS Biomedical Sciences · ExomeDNA Founder Reviewed by ExomeDNA Editorial Process | exomedna.com/methodology/editorial-process Last reviewed: 2026-05-29

This page contains general information only. For personal health decisions, consult a qualified clinician.

Uterine fibroid susceptibility is a measure of inherited genetic variation that influences the likelihood of developing benign smooth muscle tumors of the uterus — a condition affecting an estimated 70–80% of women by age 50, though most cases cause no noticeable symptoms.^[1] ExomeDNA's score for this trait draws on a genome-wide study that examined two biologically linked phenotypes — age at first menstrual period and uterine leiomyomata — simultaneously, revealing shared genetic architecture that shapes the hormonal environment of the female reproductive system across the lifecycle. Below: how these variants influence fibroid risk, the genes most consistently implicated, and what current research suggests about modifiable factors.

What is uterine fibroid susceptibility?

Uterine fibroids (also called leiomyomata or uterine leiomyomas) are non-cancerous growths that arise from the smooth muscle cells lining the uterine wall. They range from microscopic seedlings to tumors large enough to distort the uterus. Most people who have them never know — fibroids are often discovered incidentally during a routine pelvic ultrasound. When symptoms do occur, they include heavy menstrual bleeding, pelvic pressure or fullness, frequent urination, lower back pain, and, rarely, difficulties with fertility or pregnancy.

Fibroids are among the most common benign tumors in people with a uterus. They are strongly estrogen-dependent: they grow during the reproductive years (when estrogen is highest), shrink after menopause (when estrogen falls), and are more prevalent in those with earlier age at first menstrual period — because earlier menarche means more cumulative years of estrogen exposure. This hormonal connection is central to understanding why genetics plays such a meaningful role.

The ExomeDNA uterine fibroid susceptibility score reflects a higher polygenic tendency toward the hormonal and cellular conditions associated with fibroid development. A higher score indicates that the pattern of common genetic variants you carry is, on balance, more often seen in people who develop fibroids — it does not indicate that fibroids are present or inevitable.

The genetics behind uterine fibroid susceptibility

The GWAS underlying this trait used a pleiotropic design — meaning it studied two related phenotypes together: age at menarche and uterine leiomyomata (Xiao et al., 2024).^[1] This is a deliberate methodological choice. Variants that simultaneously shift the timing of puberty and increase myometrial cell proliferation are more likely to be genuine drivers of fibroid biology than variants flagged in either phenotype alone. Analyzing both traits together in the same model captures genetic factors that shape the hormonal environment of the female reproductive system across the entire reproductive lifespan.

Five genes emerge from this analysis as contributors to fibroid susceptibility: FOXO3, GCKR, PML, RIC8A, and RNLS. Each reaches the trait through a distinct biological pathway.

FOXO3 (forkhead box O3) is a transcription factor that regulates cell cycle arrest, apoptosis, DNA repair, and oxidative stress response. In the female reproductive system, FOXO3 has a well-characterized role in controlling primordial follicle activation in the ovary — when FOXO3 activity is suppressed in oocytes, follicles activate prematurely, depleting ovarian reserve and altering the lifetime hormonal trajectory. In the uterine context, FOXO3 is estrogen-regulated: rising estrogen suppresses FOXO3, removing its growth-inhibiting influence from myometrial smooth muscle cells. Genetic variants that reduce FOXO3 baseline activity may therefore leave myometrial cells with less growth restraint — a plausible mechanism for fibroid development. Because FOXO3 is also connected to menarcheal timing (earlier menarche = more estrogen-suppression years = more cumulative FOXO3 attenuation over a lifetime), it is the strongest conceptual link across both phenotypes in the pleiotropic design.^[1]

GCKR (glucokinase regulatory protein) is one of the most pleiotropic common variant loci in the human genome, with established associations with fasting glucose, triglycerides, and insulin sensitivity. GCKR regulates hepatic glucokinase activity, controlling how efficiently the liver phosphorylates glucose. Variants that reduce GCKR's inhibitory function raise post-meal glucose and promote hepatic triglyceride synthesis. The connection to uterine fibroids operates through the insulin and IGF-1 signaling pathway: uterine fibroid cells express high levels of insulin receptors and IGF-1 receptors, and hyperinsulinemia promotes myometrial cell proliferation. Observational data consistently link obesity, metabolic syndrome, and insulin resistance to higher fibroid prevalence — GCKR's role in fibroid genetics offers a plausible molecular explanation for that epidemiological pattern.^[1]

PML (promyelocytic leukemia protein) organizes PML nuclear bodies — membrane-less nuclear compartments that coordinate tumor suppression, DNA damage response, and cell senescence. PML is required for full activation of p53, the master guardian of cell cycle arrest. In myometrial tissue, functional PML nuclear bodies appear to enforce the cellular senescence programs that restrain smooth muscle cell proliferation. Loss or disruption of PML nuclear body integrity — which can result from certain variant-driven changes in PML expression — may allow myometrial cells to escape growth arrest, contributing to the benign but uncontrolled proliferation that defines fibroids.^[1]

RIC8A (resistance to inhibitors of cholinesterase 8A) is a guanine nucleotide exchange factor (GEF) for Gα protein subunits — proteins that initiate intracellular signaling cascades downstream of G-protein-coupled receptors. Sex hormone receptors, including those for luteinizing hormone (LH) and follicle-stimulating hormone (FSH), signal through G-proteins to regulate uterine smooth muscle function. RIC8A's role in priming Gα subunits for receptor activation makes it a modulator of how efficiently these hormonal signals propagate in uterine tissue.^[1]

RNLS (renalase) encodes a secreted amine oxidase that metabolizes catecholamines — epinephrine, norepinephrine, and dopamine — in circulating blood. Renalase is expressed in kidney, heart, and uterine tissue. Catecholamine levels interact with estrogen signaling in uterine smooth muscle, and variation in renalase activity may modulate the hormonal microenvironment relevant to fibroid growth. The mechanistic detail is less well-characterized than for FOXO3 or GCKR, but the signal from the pleiotropic GWAS places it in the genetic architecture of this trait.^[1]

Earlier age at menarche is a consistently replicated fibroid risk factor. The pleiotropic GWAS design (Xiao et al., 2024) exploits this biological link — genetic variants that simultaneously shift menarcheal timing and promote myometrial proliferation appear in both phenotypes, strengthening confidence that these loci genuinely shape fibroid biology rather than reflecting statistical noise in either trait alone.^[1]

What the research says

Research base: Moderate.

The GWAS informing this trait (Xiao et al., 2024) used a pleiotropic framework that is methodologically stronger than single-phenotype fibroid studies alone, because shared genetic architecture across related phenotypes is harder to generate by chance than a signal in a single outcome.^[1] However, the literature for uterine fibroid GWAS is notably less mature than for cardiovascular or metabolic trait GWAS — the authorized evidence base here rests on a single study, and the confidence tier is appropriately rated moderate.

What the broader fibroid literature confirms, independent of this specific GWAS, is consistent with the genetic signals identified here. Estrogen dependence is among the most replicated findings in fibroid biology: fibroids express estrogen receptors at high levels, grow in response to estrogen, and regress after estrogen withdrawal at menopause. Insulin and IGF-1 signaling are established growth promoters for fibroid cells, aligning with GCKR's metabolic role. PML's tumor-suppressive function in smooth muscle cells has mechanistic support from molecular studies of fibroid tissue. The pleiotropic design adds an additional layer of biological credibility by grounding fibroid risk in reproductive hormonal biology across the lifecycle.

Uterine fibroids affect an estimated 70–80% of women by age 50 — making them one of the most common benign tumors in people with a uterus — yet most cases are asymptomatic and discovered only incidentally during imaging for other reasons (Xiao et al., 2024).^[1]

The pleiotropic GWAS methodology captures a broader swath of the shared hormonal architecture underlying both earlier puberty and fibroid susceptibility. Genetic variants reaching genome-wide significance in a joint model for two related phenotypes are considered more robust than single-phenotype associations, particularly when the two phenotypes share a known biological mechanism (estrogen exposure duration). This distinction matters for interpreting polygenic scores: the ExomeDNA score for this trait incorporates variants that passed a higher biological-plausibility threshold than a single-phenotype fibroid scan alone would provide.

How uterine fibroid susceptibility affects you

The ExomeDNA score for this trait reflects the cumulative direction of common genetic variants associated with fibroid susceptibility and earlier menarcheal timing. A higher score indicates that your genetic pattern is more consistently seen in people who develop fibroids; a lower score indicates the opposite pattern. Neither extreme is a certainty — fibroids are common, and people at lower genetic scores develop them; people at higher genetic scores never do.

Several contextual factors shape how genetic susceptibility translates into actual fibroids. Age matters: fibroid prevalence rises steeply through the reproductive years and declines after menopause. Estrogen exposure duration is the key mediating factor — earlier menarche, fewer pregnancies, obesity (because adipose tissue converts androgens to estrogen) — all extend the growth-promoting environment. Conversely, factors that reduce estrogen or improve insulin sensitivity create a less favorable environment for fibroid cell proliferation.

The metabolic pathway highlighted by GCKR deserves particular emphasis. Insulin resistance and hyperinsulinemia — shaped partly by GCKR variants — directly stimulate fibroid cell proliferation through IGF-1 receptor activation, which is the biological mechanism behind the well-documented association between obesity, metabolic syndrome, and fibroid risk.

For people who already know they have fibroids, the ExomeDNA score provides context for why fibroids developed. For those who have not been evaluated, awareness of a higher genetic susceptibility is a reason to stay current on gynecological monitoring.

Working with your uterine fibroid susceptibility result

If your score is in the higher range for this trait, the following evidence-informed actions are relevant. These are not guarantees, and none substitute for clinical evaluation.

1. Maintain a healthy body weight. Adipose tissue is an active site of estrogen production — it converts androgens to estrogen through aromatase activity. Excess adipose tissue raises circulating estrogen, extending the growth-promoting environment for fibroid cells. Weight loss in those with overweight or obesity consistently reduces circulating estrogen and, in several cohort studies, associates with lower fibroid incidence and slower fibroid growth (Xiao et al., 2024).^[1]

2. Prioritize regular aerobic exercise. Physical activity reduces circulating estrogen, improves insulin sensitivity, and lowers IGF-1 levels — directly targeting the GCKR/insulin-IGF-1 pathway that promotes myometrial cell proliferation. Cohort data associate higher physical activity with reduced fibroid prevalence, independent of body weight.

3. Reduce high-glycemic dietary load. GCKR variants influence glucose-insulin dynamics, and insulin/IGF-1 receptors on fibroid cells are growth-promoting. Diets that limit rapid glucose spikes — fewer refined carbohydrates, more fiber, lower glycemic-index foods — reduce the insulin signaling burden on myometrial tissue (Xiao et al., 2024).^[1]

4. Increase cruciferous vegetable intake. Broccoli, Brussels sprouts, cabbage, and kale are rich in indole-3-carbinol and DIM, compounds that shift estrogen breakdown toward less proliferative metabolites and support estrogen clearance.

5. Screen for vitamin D deficiency and correct if present. Vitamin D deficiency has been associated with higher fibroid incidence in some study populations. Vitamin D receptors are expressed in myometrial tissue; testing and supplementing if deficient is a low-burden intervention with plausible mechanistic relevance.

6. Maintain regular gynecological monitoring. Pelvic ultrasound is the standard imaging tool for fibroid detection. For those with a family history of fibroids or a higher genetic susceptibility score, ultrasound every one to two years during the reproductive years is reasonable to preserve the widest range of management options.

7. Know the symptoms. Heavy menstrual bleeding, pelvic pressure, a sensation of fullness in the lower abdomen, frequent urination, constipation, or lower back pain are all potential fibroid symptoms warranting gynecological evaluation — especially for those with higher susceptibility.

Related traits and genes

Uterine fibroid susceptibility shares biological territory with several other ExomeDNA trait categories. The hormonal and metabolic pathways highlighted by FOXO3, GCKR, and PML overlap with traits in Metabolic Health and Women's Health.

FOXO3 intersects with cellular aging, ovarian reserve, and reproductive lifespan traits in adjacent categories. GCKR is among the most pleiotropic loci in the human genome, contributing to ExomeDNA's fasting glucose, triglycerides, and insulin resistance results — directly relevant reading for anyone whose fibroid susceptibility reflects a GCKR component. PML's tumor-suppressive role creates links to cell proliferation regulation across multiple growth-related traits in the catalog.

For users with higher fibroid susceptibility scores, reviewing Metabolic Health results — particularly insulin resistance and fasting glucose — provides a complementary view of the GCKR pathway relevant to fibroid growth promotion.

Frequently asked questions

Does a higher ExomeDNA score mean I have or will develop uterine fibroids? No. A higher score means your genetic pattern, across common variants, is more frequently seen in people who develop fibroids. Fibroids are extremely common — affecting the majority of people with a uterus by age 50 — and many with lower scores develop them while many with higher scores never do. The score is probabilistic context, not a diagnostic finding.

Why does the research study menstrual timing and fibroids together? The two phenotypes share a direct biological mechanism: earlier age at menarche means more cumulative years of estrogen exposure during the reproductive lifespan, which increases the duration of the growth-promoting environment for uterine fibroid cells. Genetic variants that simultaneously shift menarcheal timing and promote myometrial cell proliferation appear in both traits. Studying them jointly identifies shared genetic architecture more reliably than either alone (Xiao et al., 2024).^[1]

Which gene in this result is most connected to estrogen? FOXO3 is the most direct estrogen-fibroid link among the five genes in this result. Estrogen suppresses FOXO3 activity in myometrial cells, removing its growth-inhibitory effect. Variants that reduce FOXO3 baseline activity may compound this suppression, leaving myometrial cells with reduced growth restraint during the estrogen-dominant reproductive years.

Why does metabolic health matter for fibroid susceptibility? Two reasons. First, adipose tissue produces estrogen via aromatase activity, so excess body fat raises circulating estrogen levels and extends the growth-promoting environment for fibroid cells. Second, the GCKR gene in this result influences insulin-glucose dynamics — and fibroid cells express high levels of insulin and IGF-1 receptors. Hyperinsulinemia (elevated fasting insulin) directly stimulates fibroid cell proliferation through these receptors. Improving metabolic health addresses both mechanisms simultaneously.

Are uterine fibroids dangerous? Uterine fibroids are benign (non-cancerous) tumors. They do not transform into uterine cancer and do not increase cancer risk. Their significance lies in symptom burden: heavy periods, pelvic pain, pressure on the bladder or bowel, and occasionally complications during pregnancy. Most fibroids cause no symptoms and require no treatment beyond periodic monitoring.

When should someone with a higher score seek gynecological evaluation? Anyone experiencing heavy menstrual bleeding, pelvic pressure, frequent urination, back pain, or abdominal fullness should discuss these symptoms with a clinician, regardless of genetic score. For those with a family history of fibroids or a higher ExomeDNA susceptibility score, raising the topic proactively with a gynecologist — including whether routine pelvic ultrasound monitoring is appropriate — is reasonable preventive practice.

References

1. Xiao C, et al. Genetic contribution of reproductive traits to risk of uterine leiomyomata: a latent causal analysis. [Journal not specified in metadata]. 2024. PMID: 38191017.

Data sources:

• GWAS Catalog (NHGRI-EBI, accessed 2026-05-29)
• Open Targets Platform (CC0 1.0, accessed 2026-05-29)
• ClinVar (NCBI, accessed 2026-05-29) — entries at ≥2-star review status
• ClinGen Gene-Disease Validity (CC0 1.0, accessed 2026-05-29)

ExomeDNA genetic results are for wellness and educational purposes only. Consult a clinician for personalized health guidance.