mj@husky.uucp (Mark A. Johnson) (08/20/85)
What's a CBW? I've been reading this group and wondering.
Also, is sickle-cell anemia really a defense against malaria?
If so, how does it work? Isn't the cure worse than the disease?
-------------------------------------------------------------------------------
Mark A. Johnson -- Eastman Kodak Company -- Information Products
UUCP:...allegra!rochester!ritcv!husky!mj W:(716) 726-9953 H:(716) 227-2356
(The Name Says It All)
"Lived here all your life?" "Not yet."hes@ecsvax.UUCP (Henry Schaffer) (08/23/85)
> What's a CBW? I've been reading this group and wondering. > Also, is sickle-cell anemia really a defense against malaria? > If so, how does it work? Isn't the cure worse than the disease? > > Mark A. Johnson -- Eastman Kodak Company -- Information Products a)Chemical and Biological Warfare b)It is somewhat of a mis-statement to say that the *anemia* is a defense, since it is usually lethal. The recessive homozygote has anemia, but the heterozygote is (for all practical purposes) normal, but has a mixture of normal and sickle types of hemoglobin in the red blood cells, and the malarial parasites don't seem to do well in that environment - so the heterozygote has a reasonable resistance to malaria. In heavy malaria areas, this is enough to overcome the loss of the recessive homozygotes. --henry schaffer n c state univ
charli@cylixd.UUCP (Charli Phillips) (08/23/85)
In article <192@husky.uucp> mj@husky.uucp (Mark A. Johnson) writes: > > Also, is sickle-cell anemia really a defense against malaria? > If so, how does it work? Isn't the cure worse than the disease? > Sickle-cell anemia (homozygous for the malformed blood cells) is NOT beneficial to anyone. Sickle-cell trait (heterozygous for the malformed blood cells), however, does provide some protection against malaria. Sickle-cell does not follow the dominant-recessive pattern of inheritance (like albinism or dwarfism.) Rather, the two alleles are both expressed in a heterozygous individual (like blood type). It is the heterozygous form that is beneficial.
drew@ukma.UUCP (Andrew Lawson) (08/23/85)
> Also, is sickle-cell anemia really a defense against malaria?
As I understand it, sickel-cell is a mixed dominance genetic trait.
1) Those without sickel-cell at all are at higher risk from malaria.
2) Those who are have both allels for sickel-cell tend, in primitive
cultures, to die from the anemia.
3) Those with one allel for sickel cell have the benefit of malaria
resistance (or reduced severity) with some "normal" blood cells.
--
Drew Lawson
Disclaimer:
No disclaimer is needed as the entire universe exists only in
my mind. (I think, therefor I think.)