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
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
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
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.
~RE Ausetkmt's Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com)
Version: 6.0.391 / Virus Database: 222 - Release Date: 9/19/02