[LMB] OT: Genetics now unspoilered

Andi andi at diezmann.com
Mon, 25 Feb 2002 12:48:19 -0800


On 2/25/02 12:27 PM, "Virginia L Stoll" <vstoll at cs.hmc.edu> wrote:
> They also note that some XXY's have none of these symptoms except
> infertility, and some people with different genotypes have the same
> collection of symptoms.
> 
> Maybe this is a case where the definitions aren't well agreed on?  "That's
> Klinefelters, but that isn't, although it's clearly related.  He doesn't
> have one of the necessary symptoms."  Seems to happen pretty often with
> mental health diagnoses.

In my understanding (as another genetics student), Klinefelters is strictly
defined by having a genotype of multiple X chromosomes and at least one Y
chromosome. (XXY, XXXY, XXYY, XXXXY) The more extra chromosomes, the worse
the symptoms. Also, some of those with Klinefelters are mosiacs; ie, have a
mixture of XY and XXY cell lines. Although my book (Human Heredity, by
Cummings) does not say so, I'd imagine that the mixture would lead to less
symptoms than having only XXY cells.

Andi, brought out of lurking by the genetics discussion.