Toying with the unborn
TO SAY that using foetuses destined for abortion as test subjects for gene therapy would create a formidable controversy would be a gross understatement. But that is exactly what French Anderson of the University of Southern California, USA, wants to do. Anderson recently announced that he was seeking approval for foetal gene' therapy. He is, however, still developing the techniques and will begin the trials only after three years or so. "We wanted to leave time for lots of public and private discussions," he says.
Abortion is controversial probably because both supporters and opponents of the issue are equally emotional and personal about it. Over the years, abortion has acquired strong political under tones in the West, where political parties are often known to include their stand on the issue in their election manifestos. In the us, for instance, 'pro-life' activists those opposed to the concept of terminating the foetus - and those who support it frequently try to outdo each other by holding rallies, processions and workshops.
In the last few years, there have even been reports on how the pro lifers have actually taken to violence, fire-bombing abortion clinics and harassing the doctors there.
For those who came in late, Anderson is a pioneer of human gene therapy. In 1990, he treated children with severe combined immune deficiency (SCID), a hereditary disorder caused by the lack of an enzyme, a substance in the human body that initiates or promotes certain chemical changes, vital for the development of the immune system. At a recently-held meeting of the National Institutes of Health's Recombinant DNA Advisory Committee (RAC), Anderson detailed how foetuses suffering from SCID would be given healthy copies of the gene that produces the vital enzyme. He also explained his plans for in utero treatment of an inherited blood disease called alphathalassaemia.
The foetuses' small size, gives a better chance to the therapeutic genes invading reproductive organs, thereby introducing changes that will be passed down the generations. This has emerged as a major concern in the scientific community.
However, the committee had particular concerns about alphathalassaemia, a disease caused by a defect in the gene for part of the oxygen-carrying molecule haemoglobin, says, Claudia Mickelson, biosafety officer at the Massachusetts Institute of Technology and the chairperson of RAC. Each of us carry four copies of the gene that is defective in people suffering from alphathalassaemia. In worst cases, all four copies are damaged and the foetuses die either in the womb itself or shortly after birth. Even the mother can develop a life-threatening condition called pre-eclampsia, which causes high blood pressure and fluid retention. "If the therapy were inefficient, the foetus would still die, but its extended life span could increase the mother's risk," says Mickelson.
Anderson is now suggesting his team could bypass this problem by asking women who had already decided to abort their foetuses to participate in the first trial. Some RAC members agree that this avoids the ethical problems of a partial cure, but, as Anderson himself admits, it has its own difficulties. After aborting the foetus, the researchers might discover that they had managed to cure alphathalassaernia. "The parents and researchers will have this guilt that I'm not sure it's possible to emotionally prepare for," he says. The only solace, he says, is that the family would then be able to attempt another pregnancy knowing there was a treatment if the next foetus has alphathalassaemia as well (New Scientist, Vol 160,No 2155).
At least one RAC member is deeply concerned by Anderson's proposal.Lousie Markert, paediatric immunologist at Duke University Medical Center in North Carolina, USA, asks, "is it morally right to experiment on the foetus when it can give no consent and there is no way for it to benefit from the therapy?" However, Markert does appreciate Anderson's concern and applauds his attempts to begin such a controversial debate. That we are in the early stages and these issues will be debated over and over again, she feels.