EDAR rs2618428: Hair and Facial Trait Genetics
The rs2618428 variant is a single-nucleotide polymorphism located within the regulatory region of the EDAR gene on chromosome 2. Genome-wide association studies have tentatively linked this variant to physical appearance traits, including scalp hair thickness, facial structure, and beard density. Because scientific evidence linking this specific regulatory marker directly to visible differences remains limited, it serves primarily as a window into complex trait genetics rather than a definitive predictor of individual features.
What each genotype means
Typical hair and facial traits
You carry two copies of the common ancestral C allele for this non-coding regulatory variant in the EDAR region. Research links this background genotype to standard baseline hair fiber thickness, typical beard density, and typical facial feature morphology observed in broad populations. Because evidence for this specific variant is limited and hair morphology is influenced by many genes, this variant alone does not determine your visible traits.
Carried by approximately 50% to 70% of individuals across most global populations in gnomAD, representing the most common genotype worldwide.
Intermediate hair morphology profile
You carry one copy of the T allele alongside one ancestral C allele at this regulatory position near EDAR. Statistical studies indicate an additive association between the T allele and subtle variations in hair fiber cross-sectional area, beard density, or subtle facial dimensions. However, current published scientific evidence is limited, and environmental factors alongside other major EDAR variants contribute substantially to these physical characteristics.
Found in approximately 25% to 45% of individuals across diverse continental populations in gnomAD.
Varied hair thickness association
You carry two copies of the minor T allele in the EDAR regulatory region. In genome-wide association studies, this genotype has shown limited statistical correlation with variations in hair thickness, beard fullness, and specific facial proportions. Because hair and facial traits are highly polygenic and findings for this non-coding marker remain preliminary, your physical appearance may vary widely from statistical averages.
Carried by roughly 2% to 12% of individuals globally, depending on specific continental ancestry.
Understanding rs2618428 and the EDAR Region
The single-nucleotide polymorphism rs2618428 is mapped to chromosome 2 within the genomic neighborhood of the ectodysplasin A receptor (EDAR) gene. In human genetics, the EDAR locus is famous for hosting variations that alter physical traits derived from the ectoderm, such as hair follicles, teeth, and sweat glands. Unlike missense coding variants that directly substitute amino acids in the protein structure—such as the well-known EDAR V370A variant—rs2618428 resides in a non-coding, regulatory region. Regulatory variants typically influence traits by modifying the rate, timing, or tissue-specific abundance of gene transcription rather than altering the functional blueprint of the receptor itself. Because rs2618428 sits within an intricate non-coding landscape, it is often analyzed in population genetic studies alongside neighboring markers to evaluate how subtle shifts in EDAR pathway expression contribute to natural diversity in visible human morphology.
The Biological Role of the EDAR Pathway
The EDAR gene encodes a transmembrane protein known as the ectodysplasin A receptor, which belongs to the tumor necrosis factor receptor superfamily. This receptor is activated by its ligand, ectodysplasin A, triggering downstream intracellular signaling through the NF-kappaB pathway. During embryonic development, this signaling cascade is essential for the proper formation and spatial patterning of ectodermal appendages, including hair shafts, sebaceous glands, eccrine sweat glands, and teeth. Disruption or total loss of EDAR signaling in humans causes developmental conditions like hypohidrotic ectodermal dysplasia, characterized by sparse hair and missing teeth. Conversely, subtle shifts in signaling strength or expression levels govern normal morphological variation. By moderating the density and size of developing hair follicles and facial structures during morphogenesis, the EDAR pathway serves as one of the primary evolutionary engines shaping visible human diversity across different ancestral lineages.
Research Findings and Strength of Evidence
Genome-wide association studies (GWAS) and morphological scans have examined rs2618428 and nearby EDAR markers for potential links to scalp hair diameter, beard hair fullness, and subtle variations in facial profile. However, the scientific evidence specifically attributing independent functional consequences to rs2618428 remains limited. Much of the strong physical variation historically credited to the EDAR gene is driven by major coding variants such as rs3827760, which display extensive positive selection and direct biochemical changes in NF-kappaB activation. Non-coding markers like rs2618428 frequently show statistical associations simply because they are co-inherited on common ancestral haplotypes—a phenomenon called linkage disequilibrium. While statistical correlation exists between this regulatory region and ectodermal features, researchers emphasize that hair thickness, beard density, and facial structure are polygenic, shaped by dozens of collaborating genetic loci alongside lifestyle and environmental factors.
Population Frequency and Ancestral Distribution
According to reference datasets such as gnomAD and dbSNP, the minor allele at rs2618428 occurs at an estimated frequency between 0.15 and 0.35 across global populations. Unlike certain Asian-specific EDAR coding alleles that rose to near-fixation in specific geographic areas due to strong selective sweeps, rs2618428 exhibits moderate polymorphism across diverse ancestral groups, including European, African, and Asian lineages. This broader global distribution indicates that rs2618428 likely arose much earlier in human evolutionary history. Because allele frequencies and underlying haplotype structures fluctuate considerably between continental groups, any statistical association observed between this variant and traits like hair texture or facial landmarks may differ markedly depending on a person's ancestral background, underscoring the importance of multi-ancestry genomic studies.
What Consumers Can and Cannot Conclude
Discovering your rs2618428 genotype provides an engaging perspective on how non-coding genomic variation is cataloged in modern genetics, but it cannot accurately predict your personal appearance. Visible characteristics such as hair thickness, curliness, facial bone structure, and beard fullness are complex polygenic traits influenced by many genes, hormonal levels, age, and nutritional status. Carrying a particular allele at rs2618428 does not guarantee a dense beard or thick hair, nor does it imply any adverse medical condition. Because this marker is not a clinical diagnostic test or a pharmacogenomic target, it holds no actionable health or treatment utility. Consumers should view rs2618428 data strictly as educational context on human diversity and polygenic complexity, rather than a definitive personal blueprint.
How common is this variant?
Across global populations in gnomAD, the minor allele frequency of rs2618428 ranges between approximately 0.15 and 0.35. The variant is present as a common polymorphism across multiple ancestral lineages, with genotype proportions distributed across CC, CT, and TT classes according to standard population genetics models.
Frequently asked questions
Can rs2618428 predict whether I can grow a thick beard?
No. While the EDAR pathway is involved in hair follicle biology, beard growth is heavily dependent on circulating androgen levels, age, and dozens of other genetic factors. Your genotype at rs2618428 cannot reliably predict your actual beard density.
Does rs2618428 cause any ectodermal or skin diseases?
No, rs2618428 is a common non-coding variant associated only with subtle, benign population-level traits. Severe ectodermal disorders, such as hypohidrotic ectodermal dysplasia, are caused by rare, deleterious coding mutations in the EDAR gene rather than common regulatory variants like rs2618428.
How is rs2618428 different from the famous EDAR V370A variant?
The famous EDAR variant rs3827760 (V370A) directly alters an amino acid in the receptor protein, significantly increasing NF-kappaB activation and showing massive evolutionary selection in East Asian and Indigenous American populations. In contrast, rs2618428 is a non-coding regulatory variant with broader global distribution and much more limited, indirect scientific evidence.
Is rs2618428 relevant to hair loss or male pattern baldness?
Current scientific literature does not support rs2618428 as a primary driver or predictor of pattern hair loss. Androgenetic alopecia is primarily regulated by androgen receptor signaling and other distinct genomic loci rather than this specific EDAR regulatory marker.
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.
Functional variant in EDAR associated with hair fiber diameter and dental morphology.