The problem is: How do you define a man and how do you define a woman?
Chromosome counts? Then, what about intersexes?
Women, with androgen insensitivity syndrome, are assigned as girls at birth and grow up believing they are female. At puberty, they are amenstrual and they are discovered to be XY. Are they to be told they are to now be considered men, and can only marry another woman? Or worse, being told they are an 'it'?
What about girls with Turner's syndrome, female but with only one X chromosome, instead of being XX?
What about children with severe genital abnormalities? There are a significant number that were mis-assigned at birth. Some were assigned as females, because it was easier to give them a female genital appearance than male functionality. Likewise, some 'XX' babies with congenital adrenal hyperplasia (CAH), were so masculinized in their genital structure, that everyone believed they were actually boys.
How do we deal with with these cases?
IF THEY LIVE TO PUBERTY, since most don't, the issue is very very very doubtful to come up beyond mere hypotheticals.
This fool here is subject to a mental disease which even the faaaar left APA has included in their DSM IV. They treate the SYMPTOMS of the illness by mutilation.
Mis-assigned or purposely re-assigned? It would seem to me that it is relatively easy to determine the genetic gender of a baby.
If the parents decide with the doctor's help to turn their son into a girl because they're afraid of the ribbing he will get with a small or deformed penis then that's shameful and should be illegal. Likewise for girl's born with male-looking genitalia.
I would consider sex re-assignment by one person against another, especially in the case of a controlling adult against a defenseless child, as a form of battery on the level of torture and mutilation no matter what the intentions.
With the recent advances in plastic surgery and a culture that is very willing to practice on younger and younger clients (e.g. breast enlargements for teens) the vast majority of these oddball cases should be eliminated.
I don't see any problem with defining criteria by which people can be considered to be congenitally transgendered, nor with providing that such people may seek to be regarded legally as either male or female.
Such definitions would allow an XY (androgen insensitive) woman to marry an XX woman, but I would think the number of XY women wanting to marry other women would be so small as to be negligible.