/ 13 July 2004

Much ado about (almost) nothing

It wasn’t supposed to be this way. In the spring of 2000 Francis Collins and Craig Venter announced at a White House news conference the completion of ”the first draft” of the mapping and sequencing of human DNA.

With then United States president Bill Clinton and British Prime Minister Tony Blair nodding their approval, Collins and Venter agreed that racial classifications make no sense at the molecular level; we humans are 99,9% alike in our DNA.

News media around the world picked up the story, intrigued by science’s definitive refutation of racial thinking.

Not so fast. While we may all be 99,9% alike, there are three billion base pairs of human DNA, which leaves at least three million points of difference (single nucleotide polymorphisms, or SNPs) between any two people.

Armed with the promise of powerful new computer-driven technology, scientific attention is becoming riveted to that remaining 0,1% of genetic difference.

Why has science turned, after only a few years, from repudiating the existence of racial differences between human beings to generating a near obsession with them?

About the same time that the first draft of the human genome was being completed, IBM announced the development of a new Super Computer capable of performing 7,3-trillion calculations a second on human DNA. The original idea was that greater computing capacity would enable particularised therapies, because we could now turn our attention to individual differences in everything from gene therapy to the delivery of pharmaceuticals.

But gene therapy has run up against a brick wall. An experiment at the University of Pennsylvania in the US resulted in the death of the patient, Jesse Gelsinger, in late 1999.

Then another gene therapy experiment in France generated leukemia in several patients — and the protocols were stopped immediately.

So the blind alley of gene therapy has sent biotechnology heading full throttle down the road of drug development, based on the new genomics.

Here, researchers are keen to exploit national, ethnic and racial bio-databanks. A breakthrough came in December 1998, when Iceland’s Parliament approved a Bill giving a private biotechnology company legal access to a comprehensive genetic database — the first of its kind — for the country’s entire population of 270 000.

Iceland has kept medical data on its population for more than a century, including records of the deceased. By combining both stored and newly collected blood and tissue samples, and supplementing these with detailed genealogical charts and records, the biotechnology company believes that it has gained a head start in searching for the genes that are implicated in human disease. What is worrisome, however, is the putative ”ethnic purity” of the database.

According to the magazine Science, Iceland’s ”isolated position” and catastrophes that ”wiped out large parts of [its] population” have left it with ”a remarkably homogenic gene pool.” This makes it ”relatively easy to track down disease-causing mutations that might form the basis for new tests and therapies”.

Here was the foot in the door, the first step toward conceptualising strategies of research and then delivery of drugs to populations that are defined by ethnicity and race.

The next step was not long in coming. In March 2001 the US Food and Drug Administration (FDA) allowed the biotech firm NitroMed to proceed with a full-scale clinical trial of what has been touted as ”the first ethnic drug”. The trial itself was the first ever ”conducted exclusively in black men and women suffering from heart failure”.

The drug, BiDil, is designed to treat or prevent congestive heart failure by raising low or depleted levels of nitric oxide in the blood.

BiDil was originally designed for a wide population base, and race was irrelevant. But early clinical studies revealed no compelling results, and an FDA advisory panel voted nine to three against the drug’s approval.

However, BiDil was suddenly born again as a racialised remedy. This is all the more remarkable because, by concentrating only on blacks, the clinical trials now under way can have little or nothing compelling to say about comparative results according to supposed racial differences between humans.

Moreover, the underlying epidemiological mistake of such ”racial medicine” is obvious. As Michael Klag and his colleagues showed a decade ago, in general, the darker one’s skin colour, the higher the rate of hypertension for American blacks, even within the African- American community.

The differences were not biological or genetic in origin, but biological in effect due to stress-related outcomes of darker skin colour: reduced access to valued social goods such as employment, promotion, housing, and so on.

Unfortunately, while the new mantra of biotechnology is to claim that someday soon pharmaceuticals will be marketed to individuals based on their DNA, the funda- mental truth is that selling drugs is still a mass-market business.

Target markets consist of groups and population aggregates, not individuals. So, for the pharmaceutical industry, racial categorisations make economic sense.

It has always been difficult to use the market to battle racial discrimination, and many governments nowadays behave as though they would prefer to give up the fight.

But racialised drugs? They may be coming soon, accompanied by the retrograde racial thinking — with its full range of dangerous assumptions and historical associations — that molecular biology was supposed to have dispelled. — Â