emigh@ecsvax.UUCP (Ted Emigh) (01/01/70)
In article <306@drutx.UUCP> jca@drutx.UUCP (ArnsonJC) writes: >It is not the HgbS that is responsible for malaria "immunity". It is >due to lack of the Duffy Blood Group System genes, both a and b. >[ie. Fya-, Fyb-]. It just happens that both the HgbS genes and >Duffy {or should I say lack of} genes are both found in the same >segment of the population. {Blacks} > > jill There are several polymorphisms thought to influence malaria resistance, including Sickle Cell Anemia (HbS), Beta Thalassemia, G6PD deficiency, as well as the Duffy trait. It is possible for many genes to contribute to disease resistance. For more information consult: Human Genetics, by Vogel and Motulsky. -- Ted H. Emigh Genetics and Statistics, North Carolina State U, Raleigh NC USENET: {akgua decvax duke ihnp4 unc}!mcnc!ecsvax!emigh ARPA: decvax!mcnc!ecsvax!emigh@BERKELEY BITNET: nemigh@TUCC
urol@ecsvax.UUCP (Floyd A. Fried) (01/01/70)
> It is not the HgbS that is responsible for malaria "immunity". It is > due to lack of the Duffy Blood Group System genes, both a and b. > [ie. Fya-, Fyb-]. It just happens that both the HgbS genes and > Duffy {or should I say lack of} genes are both found in the same > segment of the population. {Blacks} > > jill There is an alternate hypothesis which can explain the selection of the heterozygous Hg SA state. This has to do with the fact that if individuals with Hg SA have an increased resistance to malaria then males with Hg SA will not be exposed to the numerous febrile episodes that characterize malaria. The adverse effects of high temperature on the seminiferous tubules of the testis is well known- therefore one could expect that the male with Hg SA because he is relatively protected from malaria, his testes will not be exposed to high body temperatures which will reduce the sperm count. The net effect is that the male with Hg SA will have a better sperm count and hence be more fertile than males with Hg AA.
jca@drutx.UUCP (ArnsonJC) (08/27/85)
It is not the HgbS that is responsible for malaria "immunity". It is
due to lack of the Duffy Blood Group System genes, both a and b.
[ie. Fya-, Fyb-]. It just happens that both the HgbS genes and
Duffy {or should I say lack of} genes are both found in the same
segment of the population. {Blacks}
jillwerner@aecom.UUCP (Craig Werner) (08/29/85)
> It is not the HgbS that is responsible for malaria "immunity". It is > due to lack of the Duffy Blood Group System genes, both a and b. > [ie. Fya-, Fyb-]. It just happens that both the HgbS genes and > Duffy {or should I say lack of} genes are both found in the same > segment of the population. {Blacks} > jill The Duffy Blood Groups antigens (the ones most different between whites and Blacks) is the receptor for Vivax Malaria. The HbS/HbA mutation is for Plasmodium falcifurim malaria. They are two different diseases, but both called malaria. Incidentally, I have been told that I switched one of my HbSs with an HbA. If you saw an apparent contradiction, it was an unfortunate typo. -- CW. -- Craig Werner !philabs!aecom!werner "The world is just a straight man for you sometimes"