Hair Loss
Unlearned something old today. Male pattern baldness genes are inherited from the mother? It’s a myth.
Genes that are located on the X or Y-chromosomes are call sex-linked. Genes on the other 22 pairs of chromosomes are called autosomal. It is felt that the genes governing common baldness are autosomal. This means that the baldness trait can be inherited from the mother’s side of the family or the father’s side. The commonly held notion that baldness comes only from the mother’s side of the family is incorrect, although for reasons not fully understood, the predisposition inherited from an affected mother is of slightly greater importance than that inherited from an affected father.
Despite the universal interest in the genetics of MPB, there is a surprisingly small number of scientific studies in regards to the genetics of MPB and there is only one known extensive family study on MPB. This study of hair growth patterns in 22 families concluded that common pattern baldness was an autosomal dominant phenotype in men and an autosomal recessive phenotype in women. However, the validity of these results are controversial because of a lack of details regarding examination methods and sampling errors of this study, which was published in 1916.
While I’m talking about hair loss myths, can we please also squash the one about bald men having more testosterone?
With or without testosterone, the incidence of baldness in men ranges from about 23 percent to 87 percent, and baldness may develop any time after puberty. Castration after the onset of puberty halts the progression of human balding, indicating that hormones must play a significant role. Therapeutic injections of testosterone do not result in the loss of hair in adult males treated because of a deficiency in testosterone, and there is no noticeable change in the scalp hair of normal men who receive testosterone. Perhaps low testosterone is a greater risk factor for increased balding than high or increased testosterone. Male pattern baldness, with balding limited to the top of the head, also seems to be related more to hormone deficiencies than to excess testosterone.
=v= I dunno about your testosterone source; he seems to be selling something. In general, though, the connection between this or that hormone and this or that trait is a far more complex one than most people seem to imagine. Testosterone is not a magical manly-man formula, and what it does has a lot to do with timing and what bits of your endocrine system feeling like paying attention to.
Your entry ought to be forwarded to the N.Y.P.D., because several of their "top cops" (Bernard Kerik, Bruce Smolka) are busily shaving their heads in an attempt to appear virile.
Posted by Jym on April 19 2005 14:55
Ok, how about this one?
Point is that it seems to be a combination of the presence of androgens and a genetic predisposition. Without the genetic predisposition, you can have all the testosterone you want and not lose your hair. With the genetic predisposition, you can have wholly unexceptional amounts of testosterone and lose your hair.
Baldness != predictor of greater than normal levels of testosterone.
Posted by Zed on April 19 2005 16:22