I did a google on "causes of transgender" and this is one of the links furnished by google: http://www.glsenco.org/Educators/Cou...nsgender_1.htm
It's well worth reading. As much as we'd all love to take credit for wanting to be so pretty and feminine, it turns out we had no choice So get out there and shop till you drop, girls Below is just the first part of the article
Hugs, Marci
What causes transsexualism?
excerpted from “Transsexualism: A Primer,”
2nd edition, August 1996
Re-published by The Looking Glass Society, www.looking-glass.greenend.org.uk
It is now accepted by all reputable professionals in the field that transsexualism stems from a physiological cause, and is in no way a mental illness, perversion or “lifestyle choice.” The consensus of opinion is that gender identity is determined before birth and is unchangeable thereafter.
All human foetuses start off in a female configuration, and in the absence of biochemical instructions to the contrary, will develop into baby girls—irrespective of their chromosomal sex. This “female by default” development is overridden in normal male foetuses by a complex sequence of hormonal processes. It starts about six weeks after conception, when the SRY gene on the Y chromosome causes a weak male hormone precursor to be secreted.
This causes the foetal gonads to differentiate into testes instead of ovaries. Some weeks later, the primitive testes start working, and secrete a large dose of testosterone (the principal male hormone), which causes the foetal brain to differentiate into the male pattern. It is at this point that the brain structure responsible for gender identity, as well as all the other well-known (and measurable) brain differences between men and women, is laid down.
Transsexualism is caused by that second burst of hormones failing to happen, or only happening very weakly. . . There are a number of possible reasons for this failure; in some cases, the genitals do not develop normally, and therefore do not manage to secrete testosterone on schedule to alter the brain. This is likely to produce a certain degree of physical intersex in the infant as well as transsexualism. Most transsexuals, however, are not obviously intersexed, so subtler causes must be involved.
Overall, the condition seems to have three possible causes:
1. Chromosomes: . . . A few, but by no means all, transsexuals have a nonstandard karyotype, leading to hormonal “confusion” during foetal development.
2. Chemicals: some drugs that were administered to pregnant women (most notoriously diethylstilboestrol), or oral contraceptives unknowingly taken after conception, frequently caused transsexual offspring by disrupting the hormone processes. There is also increasing evidence that some pollutants can have the same effect—many man-made chemicals are known to mimic oestrogen and/or disrupt androgen receptors.
3. Random events: sometimes, the biochemistry simply fails to work properly. . . Perhaps the expectant mother is anaemic or the foetus is undernourished for some reason, or maybe maternal hormones cross the placenta in sufficient quantity to disrupt foetal development. . . .