hair genetics question

[Sally]

Is it possible for a straight-haired person and a wavy-haired person to have a very curly-haired child? I've read that the gene for curly hair is incompletely dominant, i.e., if you combine a curly and a straight gene, you wind up with wavy hair, not with the curly you would have it that gene were completely dominant. And I've read that straight-haired people, like blue-eyed people, have only two genes for straight hair. I suppose there's the possibility that it is just the cut of their hair that makes it look straight, and it's possibly really wavy. But will a person with two genes for straigth hair have totally dead straight hair? Does hair with just a little "body" and not outright wave mean that there's a gene for curly hair in there? Or is hair genetics more complicated than this?

In other words, a straight-haired parent would be carrying two recessive straight genes (ss) and the wavy-haired parent would be carrying Cs. Only if the first were really a barely-visible wavy (Cs) could they produce curly-haired (CC) children. Otherwise, they could only have straight- (ss) or wavy-haired (Cs) children, but not very curly-haired (CC) children.

Anyway, I know a couple one of whom has what looks like straight hair and the other has what looks like wavy (not super curly) hair. Their child has super curly hair. This doesn't seem possible, given what I've described. But I've also read that the whole story about hte genetics of hair texture is not yet known. Anybody out there know some up-to-date science on this?

Yours in curiosity.....

[Katurday]

My Grandfather had straight hair, my grandmother had wavy hair, my father has like 3c hair.
My mother has 1c hair, my father again, has 3c hair, and I have about 1b hair.

[snowbird]

absolutely- no one else in my family has curly hair, only slightly wavy hair- including my extended family.

[Altocumulus]

I have wavy/curly hair, my ex-husband has very curly hair (3c maybe?), and our daughter has straight hair. She has exactly the same hair type as her paternal grandmother, uncle and several of her cousins.

I don't think hair texture follows strict Mendelian inheritance, but I don't know what rules it actually does follow. I'd be interested to find out though..I hope someone posts with the answer!

[burns_erin]

My mother has the straightest, limpest, most lifeless, straight hair I have ever seen. My father has slightly, ever so slightly wavy hair. I have very straight hair that is rather puffy with absolutely no wave at all, 2 of my sisters have crazy straight hair like our mom, and one of my sisters has what I can only call "sausage curls".

[Saranne772]

I dont know about dominance but if the dominance is true then there is always the chance that the DNA base sequence could be slightly mutated (not bad mutation just a substitution) so that a curly hair child is born

[Phalaenopsis]

I think it is something very complicated. My dad had curls, my mother has straight hair. One of my sisters has 1a hair, the other 1c, she fits the best in the theory (a mixture of both) and I have 1b hair, so it's not really logical :?

[flapjack]

As far as anything I have read, hair texture is still barely understood at all. We don't even know what all of the genes responsible for hair texture are or what they do... let alone the genes for hair colors, hair thickness, skin colors, eye colors, etc. In biology textbooks, they will tell you we know of a certain number of genes and they'll make it sound like that's all there is, but if you really dig through the journals, you'll see that we don't know jack, honestly.


So it's very much possible for anything at this point. We don't know how the whole process works, yet. At all. And I can think of plenty of people in my family and in my friends' families who have all kinds of different hair textures. I don't even think race or ethnicity has as much to do with it as we have been taught to think.


Example in my family... straight haired russian and a wavy haired asian had kids with REALLY wavy hair, curly hair and straight hair... curly haired french person and a straight haired french person and had a ton of kids with straight, wavy and curly hair... two wavy haired people had two kids with completely straight 1a hair.


I also know of other kids with straight hair and both parents have very curly hair. And so on. Sometimes traits will skip several generations, too! That further complicates things.

[sapphire-o]

Hair's waviness can change as well. My little son started out with straight hair, turned into curly ringlets for a couple years, now he's straight again. My hair was straight until I was about 30, then turned wavy. Length affect the waviness as well. Longer length usually pull curls out a bit and make waves show up more. When DH was growing out his hair I classified him as 2c/3a because it looked like hobbit hair, just curls piled on top of his head. :) Now it's only slightly wavier than mine.

[angelthadiva]

I think a picture is worth a 1,000 words:


http://i225.photobucket.com/albums/dd9/angelthadiva/100_0693.jpg

Here she is w/a little more curl:

http://i225.photobucket.com/albums/dd9/angelthadiva/100_1153.jpg

Looking at her hair; would you guess that she is a multi-racial child? I'm Hispanic and Indian and DH is African-American.

That said, no telling what is in the family history and certain genes that have laid dormant for years decide to suddenly show up.

[heidihug]

Is it possible for a straight-haired person and a wavy-haired person to have a very curly-haired child?

[raises hand]
I'm the straight-haired person, my husband is wavy-haired, and our DH20 has the curliest whorls that every whirled. Our DS16, OTOH, has quite straight hair, similar to mine, just a bit thicker.

I agree that, from what I've read, very little is known about heredity and hair texture/type/color, etc.

[Islandgrrl]

Hmmm...my father has thick-ish curly hair that was very, very dark brown in his youth (it's mostly missing now in his late 70s :) ); my mother has super thick crazy kinky/curly hair that was very light blonde in her youth (gray now, but she's got it all!). My older sister got strawberry blonde curly/kinky hair, my younger sister got carrot red curly hair (looser & smoother) and I got medium coppery auburn with the slightest bit of wave (was super straight when I was younter) and weird texture. Go figure.

My DH has thin, loosely curly hair. Our DD21 has the straightest, smoothest, glossiest hair you've ever seen. DS18 has hair that's almost the same texture as my mom's (not quite as crazy). I'll never figure it out.

[flapjack]

I went to school with a kid who was mixed Swedish and Scottish and people always thought he was part African because he had a white-blonde afro. Both his parents had slightly wavy hair, hahaha.

[lora410]

I have wavy hair and my dd dad has tight curly hair. My dd is a mix of wavy and semi tight curls :lol:

[liseling]

I dont think hair texture is controlled by only one gene, so I'm not sure if you can really talk about it in a dominant recessive type of relationship. Not only is hair texture probably controlled by several genes at once, but environment (the outer as well as inner: stress, nutrition, and hormonal changes just to name a few aspects) has a LOT to do with hair phenotype.

[noelgirl]

I really don't know the science of it, but my sister and I both ended up somewhere between our parents' textures. My dad's hair is pretty straight, maybe 1b, and my mom's hair is thick and curlyish, 3a if I had to guess but she always blow-dries so it may be even curlier than that. My sister's hair is 1c, and I'm 2b or maybe 2c in the humidity.

[shellblue1]

My mom has naturally straight hair and my dad has wavy hair. When I was little my hair looked like Shirley Temple's. Now it is a mix of curls and waves. Therefore, it is possible. Of course, the other family members' genes may have played a role in it as well. It's kind of hard to predict what type of hair a child is going to have, even hair color.

[levelek]

But if one of the parents has great hair and the other has not-so-great hair, then the children will by law inherit the great hair, yes?
*squints suspiciously at SO with not-so-great hair*

Just to throw this in here, my mum ate walnuts by the kilo all the way through her pregnancy so that I have great hair. I'm not sure about the causal link, but I did end up with pretty good hair! Thanks, mum!

[Speedbump]

Curls vs straight is also affected by hormones and can be affected by medications, etc. and chemotherapy. And for the record, both of my parents have stick straight hair. :lol:

If only it was an easy answer... maybe it is. Maybe it's this: "Everyone's hair is different, regardless of parentage." But that might be TOO simple a way to look at it. :ponder:

[Silver & Gold]

Well, I don't know all the science but I can tell you that I have wavy hair and my husband has nearly straight hair. Our children? My two youngest have hair about as straight as my husband's hair but my oldest has hair so curly it's like a poodle when he grows it out. His curly gene comes from my side of the family, My brother has the same head of hair almost exactly except that the color of my son's hair is much darker, like my husband's hair.
So, yes, it is possible for a wavy and nearly straight to have a super curly headed child.
Oh, and my brother with the curly hair? He and his wife both have very curly hair. And one of their daughters got very curly hair while the other daughter got hair a bit straighter than mine.

[Riot Crrl]

As a couple of people already pointed out, kids' hair can straighten out or curl up at different times in their lives too. I thought I would always have my mom's S-waves, but in my 30s I somehow ended up with my dad's spirals.

[Chamomilemaiden]

Genetics is so complicated thing, I don´t think everything is dicovered yet and it goes further than to our parents or grandparents.

In our family we mostly have wavy hair, except my brother whose hair is straight (good quality, fast growing hair, nothing like my breaking, fragile slowly growing hair). My hair resemble my mum´s hair, except hers were much straighter when she was younger.

[Tap Dancer]

We all have straight hair in my family but everyone else has hair that's thin to medium in thickness. Mine is very thick. My mother always says she doesn't know where all my hair came from. LOL