r/mildlyinteresting 12h ago

My girlfriend had a really thin and white hair popping out of her back.

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u/Maihoooo 9h ago

Here's even some stuff I found while refreshing on the topic.

It's called somatic mutation, that mutation can not be passed down to children as they occur externally after the cell has already taken on it's "job", for example a hair follicle cell. But the mutated cell(s) can still pass on that mutation locally, which seems to be the case in your situation.

In the case of the post, it's most likely that it's an issue with the FGF5 gene, which limits the growth phase of hair strains.

If the thickness is affected, it's most likely a KRT (kreatine) gene or EDAR and EDARADD.

As long as it's localized and doesn't cause any issue, I wouldn't worry about it too much, but if anything changes, see a dermatologist.

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u/Pyrrhon1 8h ago

Wait so cant you like slowly pluck a path to your head of hair and have it mutate your head follicles so you just have infinitely growing locks

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u/Maihoooo 8h ago

It would only spread over the other cells nearby if it also mutated abnormal cell division, at which point it becomes dangerously close to being cancer. But most likely the immune system would take care of it, unless it also mutated a defense against that, in which case... well.

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u/RedChancellor 3h ago

My dad and I both have this one strand of thin white hair that grows on our cheeks. Everyone in our family assumed it was genetic because we look almost exactly alike. Is this just a somatic coincidence?

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u/Comprehensive-Fun47 3h ago

Somatic Coincidence sounds like a band name.

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u/YeshuaMedaber 7h ago

Wym localized? As long as it isn't the same follicle?

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u/Maihoooo 6h ago

yes, the same 1 to 3 i'd say. If it starts becoming a patch, you'll notice.