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Learn · Variants · MC1R

rs1805007 MC1R

MC1R R151C homozygous. Red hair, fair skin, freckling. Increased melanoma and skin cancer risk.

Curated · human-reviewed Trait · Risk / effect allele: T · dbSNP

What is rs1805007?

rs1805007 is a single-nucleotide polymorphism (SNP) in the MC1R gene (Melanocortin 1 receptor). Each person carries two copies, one from each parent, so a result is reported as a pair of letters such as TT. The table below describes what studies associate with each genotype; the association is statistical, across populations, and is not a diagnosis.

What does each rs1805007 genotype mean?

GenotypeAssociationWhat the evidence saysConfidence
TTtypical / lowerMC1R R151C homozygous. Red hair, fair skin, freckling. Increased melanoma and skin cancer risk.88%
CT / TCtypical / lowerMC1R R151C carrier. May have reddish tones; increased sun sensitivity.82%
CCtypical / lowerNormal MC1R function.85%

How common is the T allele of rs1805007?

Minor-allele frequency by population (gnomAD / 1000 Genomes):

European10.0%
East Asian0.1%
African0.1%
South Asian0.5%
Admixed American4.0%
Global3.0%

Is rs1805007 on 23andMe and AncestryDNA chips?

Yes — it is genotyped directly on 23andMe V3, 23andMe V4, 23andMe V5, AncestryDNA V1, AncestryDNA V2. Orviva reads it from a raw-data export without imputation.

Sources

Genetic associations describe risk across populations, not a diagnosis for any one person. Most variants shift risk modestly and act alongside lifestyle, environment and other genes. Consumer DNA chips do not read every position and can be wrong at any single one. For general education only; talk to a clinician or genetic counsellor before acting on anything here, and never change a prescribed medicine without your prescriber.