MC1R: Red Hair / Fair Skin

rs1805007 · Pigmentation & Traits

MC1R is the 'red hair gene' — it also determines skin pigmentation, UV sensitivity, and affects pain perception and anesthesia requirements.

What This SNP Does

MC1R (melanocortin 1 receptor) controls the switch between eumelanin (dark pigment) and pheomelanin (red/yellow pigment). Loss-of-function variants like rs1805007 (Arg151Cys) shift production toward pheomelanin, resulting in red hair, fair skin, and freckling. Interestingly, MC1R variants also affect pain sensitivity — redheads require ~20% more anesthesia on average and are more sensitive to thermal pain.

Genotype Meanings

Genotype	Status	What It Means
CC	Non-carrier	No MC1R impact on pigmentation from this variant.
CT	Carrier	One copy. May have fair skin, light hair, freckling tendency. Slightly increased UV sensitivity.
TT	Homozygous	Strong association with red hair, very fair skin, freckling. Increased melanoma risk. Higher anesthesia requirement (~20%).

What You Can Do

Carriers should use higher SPF sunscreen, get regular skin checks, and inform anesthesiologists about MC1R status before procedures. The increased anesthesia requirement is clinically significant.

This information is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider before making health decisions based on genetic data. Genome Decoder does not diagnose, treat, or prevent any disease.