Quote Originally Posted by Alan H View Post
There are women who are genetically XXX, and multiple X, generally. It's quite an abnormal situation but it does occur. You can read about these sorts of sex chromosome abnormalities on the 'web.

However if a person acquires a Y chromosome at all, they will be physiologically "male" if they survive to birth. XXY is rare, but it does occur, the syndrome is called "Klinefelters Syndrome".
Ah, but to what extent will they be male physiologically? Internally, yes, but not necessarily externally. Apparently there is something called AIS where someone can have ordinary male XY chromosomes but their body cannot respond to male hormones, so they are born female and develop as females, but lack any internal female plumbing of any kind, and instead have undescended you-know-what.

AIS came up in the news because someone suggested that it might apply to the 800m champion, Caster Semenya, but apparently if she had that syndrome she would look and sound like a woman, which unfortunately she doesn't. Some others have suggested she might have another problem called CAH, but that raises other inconsistencies. It all goes to show that, especially if you aren't qualified, you can't diagnose someone by looking at them, especially if they have clothes on.

AIS was only suggested, it seems, because some other athletes who failed a gender test had it (who, BTW, were eventually reinstated, because they can't gain muscle due to testosterone), but it doesn't fit her atall.

Reading the news on this reveals that there are many different syndromes, and a lot of them don't even involve abnormal combinations of chromosomes, although they may not be the right ones for the person's apparent gender.

My apologies for the thread hijack. This has almost nothing to do with using DNA tests to trace your heritage.