melissaK
10-13-2009, 11:03 AM
In exploring "ideas" about why we TG are TG, my personal feelings lead me to support those who's research says it is genetic variance. It "feels" hardwired inside of me.
In my own readings I recently covered Dr. Barabara Migeon's book "Females are Mosiacs: X inactivation and Sex Differences in Disease." (Oxford Univ. Press 2007). Her professional credentials in genetics are impeccable. This book is hard science, it is not a "pop culture" book of the month.
Most of us know that women have 2 X chromosomes (chains of genes). Men have 1 X chromosome and 1 Y chromosome; women do not have Y chromosomes.
What I didn't know before reading her book is that the Y chromosome is in fact small and a fraction of the size of the X chromosome. The Y chromosome carries out extremely few duties in human males; the X chromosome carries the genes that do the heavy lifting of running our body.
When an X chromosome has a variant gene, or a broken gene, something in our body that the variant gene is supposed to do gets done differently or poorly or not at all, compared to those with the common gene. Most of us understand that this genetic variation can be beneficial or harmful and genetic variation is considered the basis of evolution.
Dr. Midegeon explains that researchers have learned that in women the two X chromosmes are not identical, and thus if one X chromosome carries a variant gene, it is unlikey the other carries the same variant gene.
In women sometimes the second X chromosome will supply the better working gene that the other X chromosome can't. This is called genetic mosaicism, and is what her book is about. In men we are stuck with what ever variant genes our single X chromosome has.
If the variant gene is crucial, women may have a backup gene. Thus, women are slightly healthier than men. They are slightly less prone to many illnesses or conditions. This is part of why they outlive men.
Dr. Midegeon concludes that anytime there is a condition that is more prevalent in men than in women, there is a high probability that it is an X chromosome genetically determined condition. And that is really why I wanted to write this post.
Because Tgism is greater in men than women, Dr. Midegon's work suggests one ought to look for a genetic factor. What particular gene might be involved is hard to determine.
For example, X chromosomes carry many of the genes that affect the ability of the body to process testosterone - and thus some males with Y chromosomes don't develop correctly because of a gene on their X chromosome. This is called "androgen insensitivity syndrome." Perhaps, something similar goes on with a gene that leads to TSism.
Dr. Midegeon complains scientists and doctors aren't fully recognizing the impact of mosaicism in treating diseases or doing research. The "we are all alike" attitude prevails more than she thinks it should. Of course, that is sweet music to my ears, as I have always known I am not like most genetic men.
hugs,
'lissa
In my own readings I recently covered Dr. Barabara Migeon's book "Females are Mosiacs: X inactivation and Sex Differences in Disease." (Oxford Univ. Press 2007). Her professional credentials in genetics are impeccable. This book is hard science, it is not a "pop culture" book of the month.
Most of us know that women have 2 X chromosomes (chains of genes). Men have 1 X chromosome and 1 Y chromosome; women do not have Y chromosomes.
What I didn't know before reading her book is that the Y chromosome is in fact small and a fraction of the size of the X chromosome. The Y chromosome carries out extremely few duties in human males; the X chromosome carries the genes that do the heavy lifting of running our body.
When an X chromosome has a variant gene, or a broken gene, something in our body that the variant gene is supposed to do gets done differently or poorly or not at all, compared to those with the common gene. Most of us understand that this genetic variation can be beneficial or harmful and genetic variation is considered the basis of evolution.
Dr. Midegeon explains that researchers have learned that in women the two X chromosmes are not identical, and thus if one X chromosome carries a variant gene, it is unlikey the other carries the same variant gene.
In women sometimes the second X chromosome will supply the better working gene that the other X chromosome can't. This is called genetic mosaicism, and is what her book is about. In men we are stuck with what ever variant genes our single X chromosome has.
If the variant gene is crucial, women may have a backup gene. Thus, women are slightly healthier than men. They are slightly less prone to many illnesses or conditions. This is part of why they outlive men.
Dr. Midegeon concludes that anytime there is a condition that is more prevalent in men than in women, there is a high probability that it is an X chromosome genetically determined condition. And that is really why I wanted to write this post.
Because Tgism is greater in men than women, Dr. Midegon's work suggests one ought to look for a genetic factor. What particular gene might be involved is hard to determine.
For example, X chromosomes carry many of the genes that affect the ability of the body to process testosterone - and thus some males with Y chromosomes don't develop correctly because of a gene on their X chromosome. This is called "androgen insensitivity syndrome." Perhaps, something similar goes on with a gene that leads to TSism.
Dr. Midegeon complains scientists and doctors aren't fully recognizing the impact of mosaicism in treating diseases or doing research. The "we are all alike" attitude prevails more than she thinks it should. Of course, that is sweet music to my ears, as I have always known I am not like most genetic men.
hugs,
'lissa