Taller East Asians face higher genetic risk of atrial fibrillation and endometriosis

Height is one of the most heritable human traits, shaped by hundreds of genetic variants interacting with nutrition, health, and environment during growth. It is also, increasingly, turning out to be a window into disease risk - not because being tall directly causes illness, but because the same genetic architecture that builds a taller body also influences cardiovascular development, hormonal signaling, and other systems that determine susceptibility to specific conditions.

Most of what we know about the genetics of height comes from European populations. A study published in PLOS Genetics, led by Fuu-Jen Tsai of the China Medical University Hospital in Taiwan, begins to fill the gap for East Asian people - and its findings are both specific and clinically suggestive.

293 variants, 120,000 genomes

The research team performed two genome-wide association studies using data from more than 120,000 Han Taiwanese individuals. The first identified genetic variants associated with height itself. The second focused on familial short stature - a largely benign condition where people are short due to inherited genetics rather than disease.

They found 293 genetic variants linked to height and five linked to familial short stature. Those numbers alone are informative: they confirm that height in East Asian populations is, like height in European populations, a massively polygenic trait - influenced by hundreds of small genetic effects rather than a few large ones.

But the study did not stop at cataloging variants. The researchers used data from five additional East Asian biobanks to estimate the health risks associated with those height-linked genetic variants. This is where the findings become clinically interesting.

The atrial fibrillation connection

Atrial fibrillation - a condition where the heart's upper chambers quiver rapidly and erratically instead of beating regularly - showed a clear association with genetically predicted height. Taller individuals carried higher genetic risk.

This finding is consistent with observations in European populations, where height has been linked to atrial fibrillation in several large studies. The biological logic is plausible: taller people tend to have larger hearts, and a larger left atrium may be more susceptible to the electrical disorganization that characterizes atrial fibrillation. The new study extends this association to East Asian populations, where both the genetic background and the environmental context differ.

Atrial fibrillation is not a trivial condition. It is the most common cardiac arrhythmia worldwide, affecting tens of millions of people, and it substantially increases the risk of stroke, heart failure, and death. Any additional tool for identifying people at elevated risk - even one as simple as a height-based polygenic score - has potential clinical value.

Height, hormones, and endometriosis

The association with endometriosis is perhaps more surprising. Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus, causing pain, inflammation, and sometimes infertility. It affects an estimated 10% of women of reproductive age globally and is notoriously difficult to diagnose, often taking years from symptom onset to clinical confirmation.

The genetic link to height likely runs through shared hormonal pathways. Height is influenced by growth hormone, insulin-like growth factor 1 (IGF-1), and sex hormones - particularly estrogen, which plays a central role in both pubertal growth and the development of endometriosis. The study found that height-associated genetic variants were also linked to the age at which menstruation begins, reinforcing the connection to reproductive hormone signaling.

Conversely, people with shorter stature were less likely to develop endometriosis. The mirror-image association adds confidence that the relationship is genuine rather than a statistical artifact.

Beyond height: body size and lung function

The study also found that height-associated variants were linked to overall body size and lung function - associations that are biologically intuitive. Taller people have larger lung volumes, and the genes influencing skeletal growth also influence the growth of internal organs. These findings serve as positive controls, confirming that the genetic variants identified in the study behave as expected in relation to well-established height-body size relationships.

Cardiovascular traits more broadly showed associations with the height-linked variants, consistent with the known relationship between body size and cardiovascular physiology. Larger bodies make different demands on the circulatory system, and the genetic variants that influence one also influence the other.

Could height predict disease risk in clinical practice?

The researchers suggest that stature-related polygenic scores - composite measures of genetic risk calculated from hundreds of height-associated variants - could help improve early risk stratification in East Asian populations. A polygenic score is not a diagnosis. It is a probability estimate, and its usefulness depends on how much additional predictive power it adds beyond information clinicians already have.

For atrial fibrillation, where early detection can guide preventive anticoagulation and reduce stroke risk, even modest improvements in risk prediction have clinical value. For endometriosis, where the average diagnostic delay is seven to ten years, any tool that flags elevated risk earlier could accelerate diagnosis and treatment.

But the authors are appropriately cautious. Their findings demonstrate genetic associations, not clinical utility. A polygenic score built from height variants would need to be tested prospectively in clinical settings to determine whether it actually improves patient outcomes - a step that has not yet been taken.

Population specificity and what remains unknown

An important strength of this study is its focus on East Asian populations, which are underrepresented in genetics research. The vast majority of genome-wide association studies have been conducted in people of European descent, and genetic findings from one population do not always transfer to another. The 293 variants identified here may overlap partially with those found in European studies, but some will be population-specific - reflecting the distinct genetic history of East Asian populations.

The study's limitations are straightforward. It is a genetic association study, which establishes correlations but not causation. The biological mechanisms linking height variants to atrial fibrillation and endometriosis are inferred from known biology, not directly demonstrated. The data come primarily from Han Taiwanese individuals, and generalizability to other East Asian populations - Japanese, Korean, Chinese mainland - needs confirmation, though the use of five East Asian biobanks provides some breadth.

The sample size of 120,000 is large but not enormous by current standards for genetic studies; recent European height studies have used cohorts of hundreds of thousands. Larger East Asian studies may identify additional variants, refine the risk estimates, or reveal associations with conditions that were below the threshold of detection here. And the clinical implications, while biologically plausible, remain untested in practice. Whether knowing that a tall person has a genetically elevated risk of atrial fibrillation would change their clinical management - prompting earlier screening, more aggressive risk factor control, or prophylactic treatment - is a question for clinical trials, not genetic association studies.

The broader significance of this work lies in its contribution to diversifying the genetics knowledge base. Polygenic risk scores developed from European data perform poorly in non-European populations because allele frequencies, linkage disequilibrium patterns, and gene-environment interactions differ across ancestries. Building equivalent tools for East Asian populations requires exactly the kind of large-scale, population-specific genetic analysis that this study represents. The 293 height-associated variants identified here are not just an academic catalog. They are the building blocks for prediction tools that could eventually help clinicians identify East Asian patients at elevated risk for conditions linked to stature - if the association findings are validated and the clinical utility is demonstrated through prospective studies.