TDF - SRY & DAX1?

[Guest]

Ok. Super geek question on Testes Determining Factor (TDF).

I read SRY is the TDF launching a cascade of other genetic effects ultimately creating a male (Medscape).

I then read DAX1 is a second required gene and thus part of the TDF minimum (Northwest University).

But the Northwest article is the only one I've seen that says "There are 2 TDF genes". So I'm lost on whether SRY is the only TDF gene or there are multiple TDF genes.

Also, is the DAX1 the ODF (Ovary Determining Factor)?

Finally, it really seems to me Kleinfelter's condition is a lkely one that Ladyboys would have. The symptoms of KF's seems like several LBs I know. Ever see a study on that?

Thanks.

[rxpharm]

Ziggy, you are getting into really heavy duty stuff! I found an article dated 2003 that reviews sexual differentiation. There is one part that goes into TDF, and SRY - which may explain what you are looking for - still not definite answers, but interesting.

Human Sexual Differentiation

With regard to your idea about Klinefelter's Syndrome explaining Thai lbs - the only real way to know for sure is genetic testing - to see if they are really have XXY sex chromosomes instead of the standard XY male or XX female ones.

I have seen one personal ad in TG Personals from a Thai lb who said she had Klinefelter's Syndrome. This is the only Thai case I know of and it is not verified. Wikpedia writes that about frequency is about 1 in 500 male births - which is high and is one of the most common genetic variations from the normal XY male karotype. It does say that XXY males are almost always sterile so this may rule out being a common factor for our lovely Thai lbs.

Klinefelter's Syndrome Wikpedia

Hats off to your ongoing research and educational postings!