EDAR rs3788336: Understanding Genetic Influences on Hair and Teeth
The rs3788336 variant is a genetic marker located within the EDAR gene, which plays a critical role in the development of ectodermal structures like hair, teeth, and sweat glands. Research indicates this variant is associated with variations in hair shaft thickness and specific dental morphology, particularly in East Asian and Indigenous American populations.
What each genotype means
Ancestral hair thickness profile
This genotype represents the ancestral state of the EDAR gene. Research indicates this version is associated with thinner hair shafts compared to the derived C allele. This is a common genetic variation and is not considered a disease-causing mutation.
This genotype is common in many global populations but is less frequent in East Asian and Indigenous American lineages where the C allele is highly prevalent.
Intermediate hair thickness profile
Carrying one copy of the derived C allele is associated with an intermediate effect on hair shaft thickness. This variant has been subject to positive selection in certain populations, influencing hair morphology and tooth shape. It is a normal variation and does not require medical intervention.
This heterozygous genotype is frequently observed in populations where both the ancestral and derived alleles are present.
Derived hair thickness profile
This genotype is associated with increased hair shaft thickness and specific dental traits like incisor shoveling. The C allele is a well-documented functional variant that has spread through specific populations due to evolutionary selection. This is a normal human variation and is not a medical condition.
This genotype is very common in northern East Asian and Indigenous American populations, where it can reach high frequencies.
What is the rs3788336 Variant?
The rs3788336 variant is a single nucleotide polymorphism (SNP) situated within the EDAR gene on chromosome 2. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is often studied alongside other functional markers in the same gene, such as the well-documented V370A mutation (rs3827760). While rs3788336 is a distinct marker, it sits within a genomic region that has been subject to significant evolutionary pressure. Scientists use such markers to track how specific traits have been selected for or maintained within human populations over thousands of years. Because this region of the genome is highly active in regulating how our bodies build external features, even small changes in the DNA sequence can lead to observable differences in physical characteristics.
The Role of the EDAR Gene
The EDAR gene provides instructions for creating the ectodysplasin A receptor, a protein that acts as a signaling hub for the development of ectodermal tissues. These tissues include the skin, hair follicles, teeth, and sweat glands. By activating pathways such as NF-κB, the EDAR protein helps coordinate the complex process of how these structures grow and mature during embryonic development. When the EDAR pathway functions normally, it ensures the proper formation of these features. Variations in this gene can alter the signaling intensity, which may lead to differences in the physical properties of hair or the shape of teeth. Because of its fundamental role in development, the EDAR gene is a primary focus for researchers studying the genetic basis of human physical diversity and the evolutionary history of different ancestral groups.
Research Associations and Evidence
Scientific research has linked variants in the EDAR gene to specific physical traits, most notably hair thickness and the presence of 'shoveling' in the upper incisors. Studies have observed that certain alleles in this gene are highly prevalent in East Asian and Indigenous American populations, suggesting that these traits may have been favored by natural selection in the past. It is important to note that while the evidence for the gene's role in these traits is strong, the specific contribution of rs3788336 compared to other nearby variants is still being refined by the scientific community. The evidence strength for this specific SNP is considered limited in isolation, as it is often analyzed as part of a larger haplotype block. Researchers continue to investigate how these genetic markers interact with other environmental and biological factors to produce the diversity of human physical appearance observed globally.
What This Information Means for You
Understanding your genotype for rs3788336 provides a glimpse into the genetic factors that contribute to your physical traits, such as hair texture or dental structure. However, it is essential to recognize that these associations are statistical in nature and do not provide a complete picture of your health or physical development. Genetics is only one piece of a much larger puzzle that includes environmental influences, nutrition, and other complex genetic interactions. This information is for educational purposes and should not be used for medical diagnosis or to make health-related decisions. If you have concerns about your dental health, hair growth, or any other physical characteristics, the best course of action is to consult with a qualified healthcare professional or a dermatologist who can provide personalized guidance based on your individual clinical history.
How common is this variant?
The rs3788336 variant and its associated alleles are common across East Asian and Indigenous American lineages, reflecting a history of positive selection in these populations.
Frequently asked questions
Is rs3788336 linked to any medical conditions?
While the EDAR gene is involved in the development of hair and teeth, rs3788336 is primarily associated with normal physical variation. It is not typically linked to clinical disorders, though other rare mutations in the EDAR gene can cause ectodermal dysplasia.
Can I change my hair thickness based on my genotype?
No, your genotype is fixed at birth. While you can use cosmetic products to alter the appearance or texture of your hair, your underlying genetic predisposition for hair thickness remains unchanged.
Why is this variant common in some populations but not others?
This is likely due to a process called positive selection, where certain genetic traits provided an evolutionary advantage in specific environments. Over time, these traits became more frequent in those populations.
Should I get a genetic test for this variant?
Genetic testing for this variant is generally not medically necessary. It is typically only encountered as part of broader ancestry or trait-based genetic reports provided by consumer genomics companies.
Sources & further reading
Educational information only, last refreshed 10/13/2026. 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.
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.
Functional variant in EDAR associated with hair fiber diameter and dental morphology.