Why do we have freckles?


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Have you ever thought about why some people have freckles and other people don't?  And why do some people have tons of freckles, and others just have a handful?

 

Standford's Museum of Innovation explains simply that freckles come from our genetics and (drum roll please...) the sun.  Freckles are made from melanin, which is a pigment that is produced from UV rays.  Melanocytes are the cells in the body that make melanin (and not every cell does this).

 

"We all have cells in our skin called melanocytes. These specialized cells are designed to protect us from the harmful ultraviolet rays of the sun. They do so by producing a pigmented protein called melanin. Melanin acts like a pair of sunglasses for your skin by making it darker. In many people, these melanocytes are spread out evenly throughout the body, but in others they aren't. They get bunched up together, resulting in freckles" ("Discovery").

 

When melanocytes are spread out, this makes people tan.  But when they're clumped up in the skin, freckles appear ("The Tech").  It is known that those with freckles have a higher risk for skin cancer ("Discovery").  (Since the sun plays a role in freckles and skin cancer the best way to avoid getting them is using sunscreen!)shapeimage_2.png

 

Something else noteworthy from this article is that freckles are more common in people with red hair (it's true - you weren't imagining it!).  The MC1R gene is responsible for both characteristics.  When parts of this gene don't function normally, the pigment builds up and produces red hair and/or freckles (depending on if one or both copies of the gene aren't working).  It is important to realize that the MC1R gene isn't the only gene affecting freckles, as not all redheads have freckles ("The Tech").

 

After reading about freckles, this made me curious about birthmarks.  My birthmark looks like a big freckle, so I was wondering if they were related.  After examining several sources, the common theme is that experts are unsure what causes birthmarks.  The science has only gotten as far as classifying the different kinds of birthmark patterns.  If you'd like to learn more about the varieties of marks, see these sources (123).


(Photo courtesy of this source)


6 Comments

My best friend Kelley has tons and tons of freckles, I always tell her that her skin looks like marble. Interestingly though, is that while her face, arms, upper back, and even legs are covered almost entirely in freckles; her lower back and stomach are paper white. She told me it's because she didn't start wearing bikini bathing suits until the age of 12 or 13 and, thus, her skin on her lower back and stomach were not exposed to the sun. Your blog post validates her hypothesis and explains why her whole body has freckles besides that area. I guess one could say, the melanin in those areas was never "activated" by sun exposure.

After reading this, I had just one question. What if someone has freckles, but nobody else in their family has them? Is it possible that they can be a recessive trait? Also, are different races prone to getting freckles (or none at all)? Is there also a chance that freckles and/or birthmarks could eventually turn into skin cancer?

Otherwise, I've always wondered why I have freckles, but my brother doesn't, and from which parent I got them from!

Before this blog I did not know that they had names to describe them. Well after reading the article I found that the birthmarks that I have, have a name and that is Café au lait spot. I already know that moles can be cancerous but I didn't know that they can be considered birthmarks. Do you have a birthmark? What is its name?

Before this blog I did not know that they had names to describe them. Well after reading the article I found that the birthmarks that I have, have a name and that is Café au lait spot. I already know that moles can be cancerous but I didn't know that they can be considered birthmarks. Do you have a birthmark? What is its name?

After looking at this blog and reading the comments I felt the same as Meghin in regards to if different races are prone to freckles. Why isn’t it common to see an African American with freckles? I am African American and I think I have freckles, across my nose and onto both sides of my cheeks but everyone in my family always brings it up, saying I must not be in the right family because no one else has freckles. So, after reading this I decided to try and figure it out once and for all, can I possibly have freckles. It turns out that no websites come out and say African Americans can’t have them, but rather that freckles are easier to see on people with fair skin. Freckles are due to an increase in the amount of dark pigment called melanin, so, anyone with this increase in melanin is capable of getting freckles. On medicinenet.com I read that common places for freckles are areas like the cheeks, nose, arms, and upper shoulders, so it is definitely possible that these are freckles!

I'm a red head with freckles, and have always been a little curious as to why that is. It's interesting to consider if other races are prone to freckles, but when considering that I think it's important to consider that red hair is extremely rare in other races, and these mutations exist on the same chromosome. Is it possible that this gene is overridden in other races because the genes that call for different skin tones and hair colors are so strong? This may be why we rarely see freckles in other races.

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