In some cultures, they’re called “little kisses of the sun,” indeed, freckles tend to become more pronounced with more sun exposure.
It is an oddity of nature that the sun can lighten a person’s hair but darken their skin. Freckles are not simply an uneven tan, though. Sun exposure results in freckling in some people when the skin pigmentation in skin cells is produced unevenly across the body. You get freckles in areas where you have more pigmentation production.
Why some people are more prone than others toward freckling has a lot to do with their genetics.
Pigmentation
Freckles are often associated with fair-skinned people, redheads, or people of Northern European descent. While it is true that freckling is more common in fair-skinned people, they occur in people of all ethnic backgrounds. The dynamic is the same.
We all have specialized skin cells called melanocytes that produce melanin. This pigmentation gives skin — along with hair and eyes —color.
Melanin also helps protect the skin from sun damage by absorbing and reflecting ultraviolet light. When the sun is out, pigmentation production ramps up. When it’s spread across our skin evenly, we get a tan. But you get freckles in areas where your skin produces more melanin.
Genetics of Freckles
To better understand the factors involved in freckling 23andMe, scientists looked at data from more than 150,000 customers of European ancestry who consented to participate in research. Our team found 34 variants in several different genes associated with freckling. Using that data and other factors like age and sex, we created a statistical model to estimate the likelihood of having freckles.
But these genetic variants also shed light on the genes responsible for melanin production. One of the variants strongly associated with freckling is in the Melanocortin 1 Receptor gene, MC1R, which is also associated with red hair.
The MC1R gene toggles the cells that produce a brown-black pigment or a reddish-yellow pigment. The color of the pigment, and how much is produced, plays a role not just in skin pigmentation but also in the color of a person’s hair. So, for some people, a variant in the gene changes the signal to make the black-brown pigment that is so protective against the sun’s harmful UV rays and instead produces more reddish-yellow pigment, which, in your hair, gives it a red color.
While genetics plays an essential role in freckling, so does sun exposure. And the two factors also work in tandem.
Sun Exposure
Freckles are usually harmless, but that doesn’t mean you should ignore them. Freckles are often more pronounced after sun exposure, for instance, and can be damaging to your skin.
Dermatologists recommend sunscreen and limiting sun exposure, especially during the middle of the day.
Beyond those protections that help against premature aging and skin cancer, you should also pay attention to your skin. Consult a dermatologist if you notice dramatic changes in a freckle’s color, shape, or size.
Find Out More
Are you curious about your likelihood of freckling or want to learn what your genetics says about other common traits? You can see your traits report here.
Not yet a customer? Check out what 23andMe can tell you about your traits here.