A 2018 meta-analysis of nearly 300,000 people found 124 loci shaping hair color, explaining more than a quarter of the heritability of red, blond, and black hair.
Hair color is one of the most visually obvious traits genetics shapes, and one of the most heritable — identical twins almost always match, and hair color runs predictably in families. It is determined largely by the amount and type of melanin pigment produced in hair follicles, the same pigment system that shapes skin and eye color.
Hysi et al. 2018 meta-analysed almost 300,000 people of European descent and found 124 loci associated with hair color — 123 on the autosomes and one on the X chromosome — with all but 13 of them newly identified. Together, these loci explained 34.6% of red hair heritability, 24.8% of blond hair heritability, and 26.1% of black hair heritability in the study populations — a substantial share for a single wave of genetic discovery. This page's own variants include nine loci tagged directly to that study: rs6440008 in ZBTB38, rs10960765 in TYRP1 — a gene already well known for its role in melanin production — and seven more spanning LHX2, PPFIBP2, TPCN2, GAB2, EDNRB, SP2, and BCAS1.
The tenth variant on this page, rs12931267 in MC1R, comes from an earlier study: Eriksson et al. 2010, a 23andMe study built around a novel design — gathering genotype and self-reported trait data entirely over the web, then testing 22 traits at once. It replicated known pigmentation genes including MC1R, one of the most consistently identified hair- and skin-color genes in human genetics, alongside new findings for traits as varied as hair morphology, freckling, and the ability to smell a distinctive compound in urine after eating asparagus.
Hair color is observed directly, not diagnosed or estimated from genotype for any medical purpose. The variants here describe population-level genetic contributions to a visible trait — they carry no clinical significance on their own.
Hair color genetics is studied partly because the same melanin pathway shapes skin pigmentation, which does carry medical relevance (for example, skin cancer risk). Nothing on this page substitutes for a dedicated look at those clinically relevant pigmentation traits, which this site covers on separate pages.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Hair Color comes down to these specific, well-studied positions — not a diagnosis.
Databases, guidelines and references
Hair color is determined largely by the amount and type of melanin pigment produced in hair follicles — the same pigment system that shapes skin and eye color. It is one of the most heritable visible human traits.
A meta-analysis of almost 300,000 people found 124 loci associated with hair color, together explaining 34.6% of red hair heritability, 24.8% of blond hair heritability, and 26.1% of black hair heritability.
It was an early 23andMe study that gathered genotype and self-reported trait data entirely over the web, testing 22 traits at once — including hair color, freckling, and the well-known finding about smelling a compound in urine after eating asparagus.
No individual variant does. These are population-level statistical associations, and hair color is observed directly rather than estimated from genotype.
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