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11091For Sale A DNA Test to Measure Racial Mix

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  • ausetkmt@geocities.com
    Oct 1, 2002
    • 0 Attachment
      http://www.nytimes.com/2002/10/01/health/genetics/01RACE.html?tntemail0


      For Sale: A DNA Test to Measure Racial Mix
      By NICHOLAS WADE


      A company in Sarasota, Fla., is offering a DNA test that it says will
      measure customers' racial ancestry and their ancestral proportions if they
      are of mixed race.

      Claiming to be "the world's first recreational genomics testing service,"
      the company, DNAPrint Genomics Inc., says its test will be useful for people
      interested in their own origins as well as for more practical purposes, like
      "to validate your eligibility for race-based college admissions or
      government entitlements."

      A test costs $290, or $160 for an initial period, and is conducted on DNA
      from cells swabbed from the inside of a customer's cheek.

      Dr. Tony Frudakis, a molecular biologist who is the company's chief
      executive, said the test would help "belie the myths on which racism is
      based" by showing that "in all of us, especially in the U.S., there is a
      continuum of ancestries."

      But geneticists independent of the company expressed reservations about the
      accuracy of any such test, noting that there was still relatively little
      data about genetic differences between ethnic groups.

      "It's possible in principle to estimate the extent of admixture, but the
      number is not going to be very accurate," said Dr. Stephen J. O'Brien, a
      population geneticist at the National Cancer Institute, referring to the
      proportion of different ancestry in people of mixed race.

      Dr. Frudakis said the test was based on a set of genetic markers known as
      SNP's, pronounced "snips," that were mostly drawn from public databases.
      SNP's are sites along the human genome where alternative chemical letters of
      DNA, the genetic material, are commonly found, with some people having one
      letter, some another.

      Working with Dr. Mark Shriver of Pennsylvania State University, DNAPrint
      Genomics has developed SNP's that are diagnostic of a person's continent of
      origin, Dr. Frudakis said. These five geographical areas correspond to the
      major human population groups or races, those of "Native American, East
      Asian, South Asian, European, sub-Saharan African, etc.," according to the
      company's Web site.

      The SNP's were validated by testing them against a panel of people from the
      five continental areas, and the accuracy of the overall test has been
      checked by comparing results with known pedigrees, Dr. Frudakis said.

      All human populations have the same set of genes and much the same set of
      variant forms of these genes, inherited from the predecessor species. But
      small differences, mostly a shift in the frequency of common genetic
      variations, have built up over time in different populations around the
      world. Study of these differences has come to the fore largely as a
      byproduct of two other lines of inquiry made possible by the Human Genome
      Project. One is the ability to track ancient migrations out of Africa from
      the different pattern of DNA changes that have accumulated among populations
      in each continent breeding in substantial isolation from one another.

      The other line of inquiry, into the identity of variant genes that cause
      disease, has run into the fact that different ethnic groups appear to have
      somewhat different patterns of genetic causation, leading biomedical
      scientists to debate whether race should be taken into account in studies of
      disease. But most researchers are still reluctant to study race as such, and
      the DNAPrint test seems to go further than anything in the published
      scientific literature.

      Dr. David B. Goldstein, a population geneticist at University College
      London, said that it was misleading to suppose that the human population
      fell into five neat groups, as the DNAPrint researchers implied, and that
      the true pattern would probably turn out to be much more complicated. "This
      test really jumps the gun in reifying groups that don't have scientific
      support," he said.

      But the test could in principle provide valid information in assessing the
      relative degree of a person's heritage from two known populations, like West
      Africans and Europeans, Dr. Goldstein said.

      He and Dr. O'Brien expressed concern that tests like DNAPrint's might do
      more harm than good. If the promise of the Human Genome Project is fulfilled
      and genetic information starts to flow into the clinic, "People will need a
      high level of confidence in what geneticists tell them, so this kind of
      casual stuff is quite dangerous if it makes people skeptical of genetic
      information," Dr. Goldstein said.

      But Dr. Shriver sees use of the test as beneficial. "The ultimate outcome is
      that we are breaking down a dichotomous classification," he said, meaning
      that instead of people being considered either black or white, his test
      would show a continuous spectrum of ancestry among African-Americans and
      others.

      The spectrum of mixed ancestry continues into the European-American
      population, about 10 percent of whom have some African ancestry, Dr. Shriver
      said. He had discovered to his surprise that that included him. Probably
      through a Mexican grandmother, he carries the Duffy null allele, he said, a
      gene variant that protects against malaria and is very common in sub-Saharan
      Africans but rare among others.

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