25 January 1998

Apparent location: USA

I have been lurking long enough.

Over 15 years ago I started some personal research with a view to writing a book. Then I got side-tracked, by life and circumstances. Now.. I'm back.

I have two references in the literature to identical twins of opposite sex, in which the phenotypic female is an XO Turner's syndrome. (Schmidt et al 1976; Edwards et al, 1966) I would like to follow this up somehow. For example, does this mean the male twin is necessarily a mosaic? Or to be more naive, where did the other X go? And to be really dumb: are there degrees or extents or mosaicism? The little reading I have done doesn't make it clear to me the mechanism and so on for mosaicism. Is it at all really well understood? And are there degrees of identicalness? Is a twin resulting from separation at the 2-cell stage more identical than, say, a twin separating from the 16-cell stage? Can twins be unequal, for example, one cell vs three cells from an unequal division at the 4-cell stage. And so There are well documented (on ultrasound for example) of singleton births after an initial twin pregnancy. Some of these males may have had Turner's syndrome twins. Is there some way, practically or theoretically, of investigating this. As you can tell I am not a geneticist, clincial or otherwise, and I realise from a few months of observing this list that the usual concerns are a bit different, which is why I am asking directly, because I have given up hoping to get any answers or directions from merely observing the list content. If there is a medical text you can recommend perhaps? I will go back into the library for a more up-to-date literature search. Any other suggestions or advice welcome.

I graduated with a medical degree in 1980 and have worked in general family medical practice since then and now want to finish some of my unfinished business before I die and get old.

Kind regards,