UM professor questions lack of diversity in genome project Narrow sample pool may benefit whites over others, she warns

February 22, 1997|By Kenneth Chang | Kenneth Chang,SPECIAL TO THE SUN

SEATTLE -- Researchers who are mapping the human genetic code have used such a narrow pool of samples that the results may primarily benefit whites, contends a University of Maryland anthropologist.

"The overwhelming majority of the genes being sequenced come from a very limited number of North Atlantic European American lineages," said Fatimah Jackson, professor of anthropology and zoology at the University of Maryland College Park.

She spoke at a panel on the Human Genome Project in the annual meeting of the American Association for the Advancement of Science, which concluded this week in Seattle.

Jackson said European DNA will be regarded as "normal" while genetic differences found later in other peoples will be regarded as variations from the norm, even though they might have come first or be more common.

If the $30 billion, federally funded effort "is to be directly relevant to African-Americans, it must shift to a new, inclusive structure," Jackson cautioned. "Otherwise African-Americans and others will have been asked to support a project that benefits a privileged few."

Scientists have been studying samples taken from 10 to 15 people, analyzing their DNA, the material that contains the instructions for making a human being. By 2005, researchers expect to map all 100,000 genes to form a composite portrait of the subjects' genetic code.

Although the United States contributes to the cost of the complex task, the effort is a multinational one that began in the mid-1980s. For example, a French team in March published part of its findings in the journal Nature.

Eventually the map is expected to help scientists pinpoint and perhaps someday cure diseases triggered by faulty genes.

Dr. Francis Collins, director of the National Center for Human Genome Research, said in an interview that diversity is not essential during the current phase of the project. "When it comes to determining a reference sequence of all the human DNA, the ethnic origin of the individuals being sampled is a relatively minor point," he said, "since the focus is on the 99.9 percent of the DNA that's identical among all of us."

Referring to the part of DNA used to track inherited traits, Collins said, "When you're talking about looking at genetic markers, then it's a much better point."

And, he continued: "When you're talking about disease susceptibilities in populations, then it's an excellent point."

When the research progress to the 0.1 percent of differences in human DNA, Collins said, "then we do need to be aware and careful about how we do this."

A scientist working on the sequencing also said the current effort seeks only to map the composite genes of a handful of people.

"I agree with what she's saying," said Glen Evans, who directs zTC the genome research at the University of Texas Southwestern Medical Center in Dallas, one of the institutions contributing to the effort. "It is not looking at diversity. That's kind of the next step beyond the Human Genome Project."

Follow-up project

Proposed but not yet funded is the Human Genome Diversity Project. Beginning in 2005, the follow-up project would address many of the issues that Jackson raised, Evans said.

In the current project, gene donors were selected in a double-blind manner so that researchers do not know the person who furnished any individual sample, and the donors do not know which, if any, of the findings correspond to their genes.

The researchers, Evans said, do not claim that the outcome of the current project will represent the genetic makeup of a "normal" person. "There is no normal human genome," Evans said.

Nonetheless that will be how people will see it, said Jackson. She charged that researchers began their task with "an opportunistic sample" that will lead to an overextrapolation of European American -- and male -- patterns as human universals.

"The first defined becomes the standard, and you have to move a mountain to change it," she said.

Genetic screening tests and therapies based on the gene map "may be essentially useless," Jackson said.

For example, the genetic defect that causes cystic fibrosis in Europeans is different from the defect that causes the same disease in other ethnic populations, Jackson said. Thus, screening tests and therapies targeted at the first gene could prove futile for most people.

More representative pool

Jackson suggested four ways to create a more representative gene pool:

Identifying the oldest lineages, mostly from eastern and southern Africa. Those lineages would presumably contain more traits that are common to all humans, she said.

Collecting samples from the largest populations, such as Chinese and East Indian females so that the findings would at least represent the majority of people.

Sampling proportionally from each geographic region based on population densities.

Selecting an international sample by random means.

"I think any educated person cannot deny the compelling qualities of her argument," said Peter Schmidt, director of the Sub-Saharan Africa Program at the American Association for the Advancement of Science in Washington, D.C., who was a member of the panel's audience.

"It's anthropologically sound. It's scientifically sound," Schmidt said.

Pub Date: 2/22/97

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