XX, XY, Chromosomes and Hair Loss
Hi, i admitantly had a bit of a dig at the answers on this site being a little generic, repetitive and indirect in my opinion. So i have a question of my own. How accurate is the following information? This information makes sense to me. Thanks i appreciate it.
The mother has two ‘Xs’ and will always give her kid an ‘X’. The father has one ‘X’ and a ‘Y’ and will give the kid one or the other. The father, therefore, determines the sex of the child. If he gives you ‘X’ then you’re ‘XX’–a GIRL, if he gives you ‘Y’ then you’re ‘XY’–a BOY.
“X-linked” disorders are defects in one of the thousands of genes found on the ‘X’ chromosome. These disorders can range from severe mental retardation to more harmless things like color blindness or PATTERN BALDNESS. The reason that males are more susceptible to an X-linked disorder is that when mom gives her son an ‘X’ carrying the defective gene, dad gives the son a ‘Y’, which cannot back up the defective ‘X’. Women seldom get these disorders since the chances of getting two bad ‘Xs’ for the exact same gene are quite slim.
So as far as whose fault it is, blame both parents–Mom for giving it to you, and dad for not backing you up.
Now another point should be made about where to look for the bald ‘X’ in a mother’s family. You have to look at EITHER the (1) mother’s father OR (2) her brothers:
(1) Grandpa has the bald ‘X’ (and is bald) and passed it to your mom/her sisters-who give it to half of their sons. (remember mom’s brothers would only get the ‘Y’ and would not be bald in this case).
(2) Grandpa has a good ‘X’, but Grandma has bald ‘X’/good ‘X’ and gives a 50/50 ratio to kids, so half of mom’s brothers are bald.If you are grandson of all this, then in scenario (1) you have 50% chance at baldness, scenario (2), a 25% chance.
Both (1) AND (2) are possible in the same family, but would be rare and might lead to bald women in the family (depending on other factors such as testosterone levels)
I am not a geneticist. I am a physician. And the genetic argument as you pose is a simplified understanding of high school biology or college biology 101 at best.
The inherited traits are far more complex than X or Y chromosomes. While it is true that the father’s XY chromosome determines the sex of the unborn child, the balding gene is not in the Y chromosome. There are things called expression that distort our understanding of the genetics. Actually, no one really knows. That is why you cannot and will not find the answer… yet.
Thanks for the mention(s); very useful, informative and comprehensive.
This really has confused me now. Throughout all the hereditary theories of MPB I’ve seen, no matter how different they are, one thing that has remained constant is that in determining you’re hair, you only have to look at your Dad or your Mum’s Dad. My Dad started to lose his hair at 18 and was totally bald on top by 40, yet my Polish granddad is almost 90 and still has thick wavy hair in a ponytail, no joke… 100% hair still, no receding hairline, no thinning crown, plenty of stress from WW2 and it seems not a single hair falls from his head. I had no signs of baldness at 18 but 7 years on I show an ever so slight receding hairline, no thinning anywhere else. This makes me think I’ve taken after my dad, despite having hair like my Mum and Granddad… thick and wavy.
Obviously I’ve got an X from Mum and a Y from Dad because I’m a guy, so if the baldness gene isn’t in the Y chromosome, then how am I losing my hair, particular seeing as how I don’t have hair like my Dad anyway, which was dead straight and fairly fine. There’s also no baldness with any of the men in my mum’s family. All my uncles have full heads of hair. All of my Granddad’s brothers, most of whom I regularly see, all have hair. His dad (Gr. Granddad) also had a thick head of hair although not wavy. I even found a picture of my Granddad’s maternal granddad (Gr. Gr. Granddad) who is Cheyenne Indian (somehow) who had the typical very long straight hair…but no baldness, Indians don’t seem to go bald. I even found pictures of my Nan’s brothers and her dad, who only showed slight thinning all over there head very late on in life. My dad’s family have virtually all gone completely bald though. My granddad didn’t start to lose it at 18 but instead at about 30, few years older than me now. My Dad’s maternal Granddad had apparently only lost half his hair at around 50, not all of it at 40. Still my Dad went bald faster than both his Dad and Mum’s dad. Naturally you’d think he’d taken after the one who went bald quickest, his dad, but like me his hair style was more like his mum’s side than his Dad’s, and like me how could he have taken after his Dad if the baldness gene isn’t in the Y chromosome.
I know its long but please answer, I feel as though I couldn’t be any more unlucky having such good genes on my Mum’s side.