EDAR rs2300465: Hair and Ectodermal Trait Genetics
rs2300465 is a single nucleotide polymorphism situated within the EDAR gene on chromosome 2. This gene encodes the ectodysplasin A receptor, a key signaling molecule that guides the prenatal development of ectodermal structures like hair follicles, teeth, and sweat glands. Research links variation at this locus to subtle differences in hair fiber thickness and related physical traits, though its individual clinical impact remains limited.
What each genotype means
Typical hair fiber diameter
You carry two copies of the C allele for this EDAR gene marker. Research links this background genotype to standard hair fiber thickness and typical dental morphology commonly seen in global reference populations. It is not associated with the increased hair shaft diameter observed with the alternative T allele.
This is the predominant genotype across European and African ancestries, but it is less common in East Asian and Indigenous American populations.
Intermediate hair strand thickness
You carry one copy of the T allele and one copy of the C allele in the EDAR gene. In genetic studies, carrying a single derived allele is associated with intermediate hair strand diameter and subtle differences in dental and ectodermal features. Because hair traits are polygenic, your individual hair texture will also depend on other contributing genes.
Carried by a significant proportion of individuals of East Asian, Central Asian, and Indigenous American descent, while relatively rare in individuals of European and African descent.
Increased hair fiber diameter
You carry two copies of the T allele for this EDAR variant. Population studies strongly correlate this genotype with noticeably thicker hair fiber diameter, straighter hair shaft geometry, and characteristic incisor shoveling. These variations reflect normal human physical diversity and do not represent a medical disorder.
Common in East Asian and Indigenous American populations, where it reaches high frequencies, but rarely found in populations of European or African ancestry.
Genomic Location and Variant Characteristics
The single nucleotide polymorphism rs2300465 is located on human chromosome 2 within the EDAR gene, as cataloged in public genomic databases such as dbSNP and Ensembl. The primary functional alleles observed at this position involve a single base transition between guanine (G) and adenine (A). Unlike severe mutations that ablate receptor function, rs2300465 represents a common polymorphic site. In the broader genome, it resides in an extensively studied genomic region that reflects substantial evolutionary adaptation in human populations. Although frequently tracked on consumer genotyping microarrays and population sequencing projects, its specific molecular impact is modest when evaluated in isolation compared to classic gain-of-function variants in the same locus.
Biological Role of the EDAR Gene
The EDAR gene provides instructions for producing the ectodysplasin A receptor, a transmembrane protein belonging to the tumor necrosis factor receptor superfamily ([EDAR gene: MedlinePlus Genetics](https://medlineplus.gov/genetics/gene/edar)). EDAR operates within a tightly regulated embryonic signaling cascade that activates the NF-kappaB transcription factor pathway during early tissue formation. This signaling pathway is essential for the morphogenesis of ectodermal derivatives, determining the number, size, and patterning of hair follicles, eccrine sweat glands, sebaceous glands, and teeth ([EDAR Gene - GeneCards](https://www.genecards.org/card/EDAR)). While loss-of-function mutations in EDAR lead to hypohidrotic ectodermal dysplasia, benign regulatory and missense variations shape ordinary variation in human physical morphology.
Research Associations and Strength of Evidence
Genome-wide and candidate gene association studies have linked polymorphisms across the EDAR locus to differences in hair strand thickness, cross-sectional area, dental characteristics such as incisor shoveling, and facial appendage structures ([Entry - *604095 - ECTODYSPLASIN A RECEPTOR; EDAR - OMIM](https://omim.org/entry/604095)). However, the scientific evidence directly tying rs2300465 to these traits is categorized as limited. Much of the strong biological effect observed in East Asian cohorts is driven by neighboring functional variants in strong linkage disequilibrium, such as the well-characterized EDAR 1540T>C (Val370Ala; rs3827760) variant ([NM_022336.3(EDAR):c.1109T>C (p.Val370Ala) AND Hair morphology 1, hair thickness - ClinVar - NCBI](https://www.ncbi.nlm.nih.gov/clinvar/RCV000006216.2)). Consequently, statistical signals at rs2300465 may reflect regional haplotype structures rather than an independent causative driver of hair or dental architecture.
Global Allele Distribution and Ancestral Shifts
Data from large population resources like the Genome Aggregation Database (gnomAD) and the 1000 Genomes Project show that rs2300465 is present globally but displays notable frequency differences across major continental ancestries. While common across African, European, and South Asian groups, frequency shifts at this and linked EDAR loci are pronounced in East Asian and Indigenous American populations due to historic positive selection on the surrounding chromosomal region ([bioRxiv](https://www.biorxiv.org/content/10.1101/813063v1.full-text)). Because the local genomic architecture differs significantly among diverse demographic groups, an association identified in one population cannot be automatically generalized to individuals of different ancestral backgrounds.
Interpretation and What You Can Do
Discovering your rs2300465 genotype offers an intriguing glimpse into human evolutionary genetics, but it cannot diagnose any medical condition or accurately predict your exact hair texture on its own. Physical traits like hair fiber diameter and dental shape are complex and polygenic, shaped by dozens of independent genetic loci alongside nutrition, environmental factors, and aging. This variant does not carry medical pathogenicity or alter pharmaceutical drug metabolism. Readers should view rs2300465 purely as an educational marker of normal human phenotypic diversity, and any concerns regarding hair loss or dental anomalies should be discussed with a qualified medical professional.
How common is this variant?
rs2300465 is common across global populations in gnomAD, displaying distinct ancestral frequency shifts between African, European, and Asian lineages due to regional evolutionary history.
Frequently asked questions
Does having the rs2300465 variant cause hair loss or baldness?
No, rs2300465 is not associated with androgenetic alopecia or pathological hair loss. The EDAR gene family influences the physical characteristics of hair development, such as fiber diameter and straightness, rather than premature follicle miniaturization or pattern baldness.
Can rs2300465 predict whether my hair will be thick or thin?
Not reliably on its own. While the EDAR locus is linked to variations in hair cross-sectional area, hair thickness is a complex trait influenced by many genes and environmental factors. rs2300465 alone provides only limited predictive value.
Is rs2300465 related to hypohidrotic ectodermal dysplasia?
No, rs2300465 is a benign common single nucleotide polymorphism, not a disease-causing mutation. Severe clinical disorders like hypohidrotic ectodermal dysplasia are caused by rare, pathogenic loss-of-function mutations within EDAR or its signaling partners.
Why do allele frequencies at this locus differ so much between ancestries?
The genomic region surrounding EDAR underwent strong positive natural selection thousands of years ago, particularly in ancestral East Asian populations. These evolutionary sweeps altered the frequencies of many common variants across the locus, creating distinct ancestral frequency differences today.
Sources & further reading
Educational information only, last refreshed 9/11/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Functional variant tightly linked to hair shaft thickness, sweat gland density, and distinct East Asian dental morphology traits.
Functional variant (V370A) in the EDAR gene influencing hair thickness and sweat gland density.
Non-coding regulatory variant in EDAR associated with variations in hair fiber thickness, crown morphology, and dental traits.
Intronic regulatory variant tightly linked to hair follicle density, incisor shoveling morphology, and sweat gland branching in continental Asian populations.
The 370A (Val370Ala) variant is a classic example of positive selection in East Asian and Native American populations, affecting hair thickness and sweat gland density.
Common regulatory variant in the EDAR region associated with variation in human hair thickness, beard density, and facial shape.