In article <Pine.SUN.3.91.950125184021.8827A-100000 at grus.cus.cam.ac.uk>,
Mike Clark <mrc7 at CUS.CAM.AC.UK> wrote:
>On Wed, 25 Jan 1995, Rachel Teitelbaum wrote:
>>> > There are anumber of other mutations which are
>> > protective for malaria and which are present in the african and
>> > mediteranean
>> > populations and the high frequencies are thought to be maintained by
>> > selection through the disease.
>>>>>> Would thallisemia be included in these?
>>>>Yes, and there are several independent mutations which appear to give
>rise to some protection against malaria.
I don't know whether it has been demonstrated directly, but loss-of-
function mutations in glucose-6-phosphate dehydrogenase (G6PD) are believed
to be protective against malaria, too. The frequency of G6PD mutations in
malaria-infested countries is much higher than the frequency without. Like
sickle-cell, G6PD deficiency is believed to be protective in heterozygotes,
and deleterious in homozygotes -- only G6PD is also X-linked, so only females
can be heterzygous.
--
Unique ID : Ladasky, John Joseph Jr.
Title : BA Biochemistry, U.C. Berkeley, 1989
Location : Stanford University, Dept. of Structural Biology, Fairchild D-105
Keywords : immunology, music, running, Green
