Freckling / sun sensitivity

IRF4 influences the pigment cells of skin, hair and eyes. This variant is strongly linked to freckling and sun sensitivity in people of European descent.

Possible results

Less freckling. You don't carry the IRF4 freckling variant, so from what this gene shows you tend toward fewer freckles and a bit more sun tolerance. Pigmentation involves many genes, so this is one of several.

Some freckling. You carry one copy of the IRF4 variant linked to freckling and sun sensitivity. You may freckle somewhat and burn a little more easily, though the effect is stronger with two copies.

More freckling. You have two copies of the IRF4 variant strongly tied to freckling, lighter hair and sun-sensitive skin. You likely freckle and burn easily, so sunscreen and shade are good habits.

Evidence & sources

Across global populations, about 2% of people carry two copies of this variant, and about 82% carry none.

This variant appears in 10 published genetic studies: PubMed 20585627 · PubMed 23548203 · PubMed 25705849 · PubMed 25963972 · PubMed 30166351 · PubMed 30664655 · PubMed 36536295 · PubMed 36672889 · PubMed 39024449 · PubMed 41477839.

Related

Body mass index · Endurance / aerobic capacity (PPARGC1A) · Eye color (blue, green/hazel, brown) · Hair thickness / shovel-shaped incisors · Height · Red hair / fair skin (MC1R gene) · Skin pigmentation (light vs dark)