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Gene variations make Africans more susceptible to HIV

Discussion in 'Habari na Hoja mchanganyiko' started by The Truth, Jul 17, 2008.

  1. T

    The Truth JF-Expert Member

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    Gene Variation May Make Africans More Susceptible to HIV Infections

    By GAUTAM NAIK
    July 16, 2008 7:31 p.m.

    An ancient genetic variation that protects people of African descent against a certain type of malaria may also make them 40% more susceptible to HIV infection, a new study has found.

    The result could shed some light on why there is such a large discrepancy among world-wide populations in the prevalence of HIV, the virus the causes AIDS. Africa, for example, has 25 million people infected with HIV, a much higher infection rate than other populations that isn't entirely explained by differences in sexual behavior or social factors. The latest finding suggests that genetics also plays a significant role.

    "It helps in part to explain why HIV is so prevalent in Africa. Most Africans have a slight genetic bias to being more susceptible" when exposed to the virus, said Robin Weiss, a virologist at University College London and a co-author of the paper.

    But the news isn't all bad. In another twist, the researchers found that the same genetic alteration appears to prolong survival in those infected with HIV by about two years.

    The study, which took more than five years to put together, was conducted by researchers in the U.S. and United Kingdom. It appears in Cell Host & Microbe, a new scientific journal.

    Scientists said that while their work was part of a larger push to understand the complex underlying genetics of HIV infection, there were no immediate practical benefits. In theory, a "susceptibility test" based on the gene variant would be easy to create; however, it might persuade those who don't have the genetic trait to pursue more risky behavior and increase their chances of getting infected.

    Knowing more about the genetic roots of HIV "raises the possibility that not only will we understand how disease is caused, but it also helps us in areas such as vaccine trials" in which genetic differences among individuals can yield differing results, said Sunil Ahuja, a physician who specializes in infectious disease at the University of Texas Health Science Center at San Antonio and is co-author of the paper.

    In their study, the researchers focused on a gene that encodes for a protein found on the surface of red blood cells, called Duffy Antigen Receptor for Chemokines. Though the exact mechanism isn't yet well understood, here is what researchers speculate: People with the Duffy protein carry on their red cells and in their circulatory system a larger amount of immune molecules known as chemokines, which confers protection against HIV. In addition, the Duffy protein can act as a sponge and soak up infectious HIV particles, providing additional protection against the virus. People who have a variation of the gene – which includes a large proportion of people of African descent – don't carry the Duffy protein, and are therefore at higher risk of getting infected when exposed to HIV.

    According to the study, 90% of people in Africa and 60% of African-Americans carry the variant gene. In Africa, the scientists estimate that roughly 11% of the HIV burden may be linked to this genetic variation. The study was based on data collected over 25 years by the U.S. Air Force, and included samples from both African-Americans and those of European descent.

    http://online.wsj.com/article/SB121622425427558899.html?mod=googlenews_wsj
     
    Last edited by a moderator: Jul 17, 2008
  2. T

    The Truth JF-Expert Member

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    This study is important for a number of reasons beyond showing that Africans are genetically more prone to HIV infections:

    1) It challenges the egalitarian notion that different groups are equal biologically i.e. we are all the same inside. There is a genetic variation among groups.

    2) If a genetic variation that explains HIV infection susceptibility among Africans, why not genetic variation that explains IQ or intelligence differences? This can not be further behind.
     
  3. R

    Rwabugiri JF-Expert Member

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    Hii sayansi sasa mwishowe itasema we are diferent species!
     
  4. T

    The Truth JF-Expert Member

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    I don't believe different races are different species as cross breeding between species has never been proven. Africans can breed with Whites, Asians etc. But group differences are still significant enough biologically. Maybe different races are different subspecies.
     
  5. B

    BP Biscuit Mane Member

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    Aaahh! Finally I get to spy Monkey Supporter doing what Monkey Supporter enjoys doing best, namely arguing and peddling the latest pseudo-scientific racist mumbo jumbo, thinly-veiled as legit top-notch research "findings" about the inherent nature of so-called human racial differences.

    Hopefully some fools (like the poor naïve fellow above) will fall for the bait, thus inciting and offering Monkey Supporter a much longed opportunity to spew long-held vile, grievous and purportedly "scientifically" proven racist held theories, beliefs, opinions and prejudices against peoples of African descent.
     
  6. R

    Rubabi Senior Member

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    IO look at these studies done by europeans puttting africans on PEDESTAL SUSPICIOUS.

    Africans need to do their own studies on europwans as 'subjects'.

    HAVE YOU HEARED A STUDY LIKE THIS BELOW BEING PUBLICISED?


    --------------------------------------------------------------
    AFRICANS MORE GENETICALLY FIT


    White Americans are both genetically weaker and less diverse than their black compatriots, a Cornell University-led study finds.

    Analyzing the genetic makeup of 20 Americans of European ancestry and 15 African-Americans, researchers found that the former showed much less variation among 10,000 tested genes than did the latter, which was expected.

    They also found that Europeans had many more possibly harmful mutations than did African, which was a surprise.


    "Since we tend to think of European populations as quite large, we did not expect to see a significant difference in the distribution of neutral and deleterious variation between the two populations," said senior co-author Carlos Bustamante, an assistant professor of biological statistics and computational biology at Cornell.

    But the Cornell study, published in the journal Nature Thursday, indicates that Europeans went through a second "population bottleneck," probably about 30,000 years ago, when the ancestral population was again reduced to relatively few in number.



    The doubly diluted genetic diversity has allowed "bad" mutations to build up in the European population, something that the more genetically varied African population has had more success in weeding out.

    "What we may be seeing is a 'population genetic echo' of the founding of Europe," said Bustamante.

    The Cornell team hopes to study other population groups in search of similar results.

    For example, Native Americans show even less genetic diversity than Europeans, having descended from a few thousand people who entered North America about 10,000 years ago.

    That fact was reinforced by a larger-scale study, also published in Nature, led by scientists from the Universities of Michigan and Virginia who analyzed genetic samples of 485 individuals scattered around the globe whose DNA is recorded in a French databank.

    As would be expected with the "out of Africa" theory, the researchers found Africans had the greatest amount of genetic diversity, followed in turn by Middle Easterners, then Europeans and South Asians at about equal levels, then East Asians.

    Native Americans had the least genetic diversity of all, indicating that part of the world was settled last.

    "Previously, we've been able to look at the genome and say, 'This part is from Africa, this is from Asia,'" explained Virginia research Andrew Singleton to Wired News. "Now we can look past that and say, 'It's from this part of Africa or Eurasia.'"

    A third study, published in the journal Science on Friday, may be the most fascinating of all.

    Drawing on 935 individual samples from the French databank, a Stanford University team found deep traces of long-ago population movements, all originating from a "ground zero" in Ethiopia, Kenya or Tanzania.

    For example, the Pygmies of the Congo forest were found to be quite close to the Bushmen of Namibia — but both were very different from most other sub-Saharan groups.

    The fierce and proud Bedouin nomads of the Middle East actually have a lot of European and South Asian blood.

    The Asian-looking Hazara of Afghanistan are correct in claiming ancestry in Mongolia, but the Han, the dominant ethnic group in China, may be disappointed to discover they're actually two peoples, one north, the other south.

    Native Americans have at least one closely related group in Asia — the Yakuts of eastern Siberia, who themselves are related to other hunter-gatherer Siberian tribes, some of whom build wooden teepees.

    The Basques in northeastern Spain and southwestern France may be right to demand their own nation — they're not closely related to anyone else. Surprisingly, neither are the residents of Sardinia off the coast of Italy.

    As with the other large-scale study, the Stanford team found the greatest diversity outside of Africa among people living in the wide crescent of land stretching from the eastern shore of the Mediterranean to northern India.

    Not only was the region among the first colonized by the African migrants, they theorize, but the large number of European and East Asian genes among the population indicates that it's long been the human highway, with large numbers of migrants from both directions conquering, trading and generally reproducing along its entire length.
     
  7. T

    The Truth JF-Expert Member

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    This is a childish drivel. If the research on the article I posted was pseudoscience then it would have been discredited by now. Maybe your belief system of "we are equal biologically" (if that's what you subscribe to) is based on pseudoscience and unfounded. The human genome has been mapped and we are learning more about ourselves. Things are coming out that will make many people uncomfortable and even upset. But we must let the chips fall where they may.
     
  8. T

    The Truth JF-Expert Member

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    Please provide source of this article.
     
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