Feature

Isn’t it time you changed your make-up?

Rapid advances in genetics promise startling new solutions to problems we never knew we had - and the tendency is to reduce complex social issues to individual problems with a technical fix, warns Paul Martin

The report that scientists have discovered a gene causing homosexuality is just the latest in a string of stories linking genes to schizophrenia, depression, cancer, diabetes, alcoholism and even criminal behaviour.

Rarely a week goes by without more news of breakthroughs in biotechnology, genetic engineering and reproductive techniques, and in the specialist scientific and medical literature there has been an explosion of reports and publications on genetic disease.

We are witnessing an intellectual paradigm shift; a revolution in how health, illness and even our own behaviour is accounted for. In contrast to the complex interaction of social and environmental factors which have traditionally been seen as the cause of most health problems, simple genetic explanations are rapidly gaining credibility. Illnesses such as heart disease and cancer can now be explained in terms of gene defects rather than poverty, stress or smoking.

This changing view of human health is fuelled by massive investment in research into the biomedical sciences. In the public sector the $3bn Human Genome Project involving the US, Europe and Japan, aims to map every gene in the body and is the biggest single programme ever carried out in biology. In the private sector, more than 700 new biotechnology firms have been started in the US during the last decade spending over $2bn a year on medical research.

Three strands of research are coming together to create this new medical paradigm; the rise of genetic screening tests, the development of gene therapy and work on behavioural genetics. The application of this new knowledge is already leading to startling new possibilities, but is also creating profound and disturbing social and ethical problems in its wake.

Genetic screening

Genetic tests are now being developed to screen people for inherited diseases and predispositions to ill health. With the flood of genetic information being discovered by the Human Genome Project a wide range of new screening tests are certain to become available. Already it is possible to detect the genes which cause a number of inherited conditions, including muscular dystrophy, Huntingdon’s chorea and cystic fibrosis, and in the short term doctors should be able to screen for rare forms of heart disease and cancer.

Pre-natal genetic screening is already routinely carried out to detect if a child is likely to be born with a crippling inherited illness, such as cystic fibrosis, in families with a history of the disease. When a baby likely to suffer from a genetic illness is detected, the mother is given the choice of an abortion.

Critics of the new genetics worry that as screening becomes more sophisticated, the pressure on women to bear perfect, healthy babies will lead to the increasing use of selective abortion to eliminate ‘undesirable’ traits. Rather disturbingly, a recent survey found that 11 per cent of Americans would terminate a pregnancy if their child was diagnosed as likely to be obese.

The increasingly widespread use of genetic screening also open the door to new forms of discrimination, where people diagnosed as predisposed to an illness or who are just healthy carriers of a particular gene are denied access to insurance, education and even employment. In the US, where screening is more common, cases of genetic discrimination have already been documented. Already a number of states in the US have passed laws prohibiting the use of personal genetic information in health and life insurance, and Congress is discussing tough ‘genetic privacy’ laws to prevent the misuse of genetic screening.

Gene therapy

Gene therapy is the use of synthetic genes made of DNA to ‘correct’ genetic defects and combat major disease by ‘reprogramming’ the body’s cells. This is in contrast to conventional drugs which work on biochemistry and metabolism, and generally only have short term effects. There are two types of gene therapy: germ-line therapy, where genetic alterations are made to the developing embryo and can be passed on from one generation to the next (in effect human genetic engineering), and somatic therapy, where genetic changes are not inherited. A recent UK government committee on the ethics of gene therapy concluded that germ line therapy was ethically unacceptable, but that somatic gene therapy could go ahead.

The world’s first somatic gene therapy trial in humans was carried out in 1990 on two young girls suffering from ADA deficiency, a very rare fatal genetic defect which meant they had virtually no immunity against infection. Today they are able to lead normal lives. There are now over 30 different clinical trials of gene therapy in the US, and the first trial in the UK was started earlier this year.

Although none of these trials are seeking to make changes which can be passed onto future generations, powerful techniques which might allow germ line gene therapy are already being developed. A large number of ‘transgenic’ animals have already been created, where human genes are introduced into the embryos of other species. For example, a flock of sheep is being bred which produces human factor VIII in their milk (to treat haemophilia) and a mouse strain which always develops cancer has been created as a way of testing potential cures.

Some leading scientists and ethicists are already arguing that germ line gene therapy should be allowed as a way of preventing disease in future generations. The Economist magazine has gone further and suggested that people should be able to cosmetically enhance their children by changing their skin colour or body shape using gene therapy.

Behavioural genetics

In both the UK and the US major research programmes have been set up to try to find a genetic ‘cause’ for what have previously been thought of as complex social problems, including, alcoholism, depression, schizophrenia, and even aggression. Already many claims have been made linking genetic defects with these conditions, but in every case the research has either been retracted, disproved or disputed. In the case of the so called ‘gay gene’, it remains to be seen if this research can withstand scrutiny, but the long history of spurious and exaggerated claims linking genes and behaviour offers faint hope of a firm link between genetics and sexual preference. Sadly, the truth hardly matters. Despite the lack of real scientific evidence, many people now believe that important aspects of human behaviour are genetically determined and this is leading to a resurgent interest in neo-eugenic ideas.

In a recent national TV programme in the US, doctors discussed the idea of making prenatal genetic screening routine and selective abortion of unhealthy children compulsory in order to cut health care costs, arguing that some babies may be judged ‘unfit to be born’. In the UK, some ultra-orthodox religious leaders suggested that genetic engineering might be used to eliminate homosexuality. Unfortunately, it is too often forgotten that in the earlier part of this century eugenic ideas were not just the inspiration for the Nazi holocaust. Laws permitting the forcible sterilisation of the genetically ‘unfit’ were passed in the US, Canada, and throughout Scandinavia between 1907 and 1930. In the US over 12,000 criminals and ‘mental defectives’ were sterilised against their will.

The West is unlikely to see a return to respectability of traditional eugenic ideas of racial superiority or the threat posed to society by the genetically inferior; although the ethnic cleansing of Bosnia has been motivated by similar principles. Instead, a paler free market eugenics may come about, where people can pay private clinics to selectively abort or genetically enhance their babies.

Taken together the three strands of genetic screening, gene therapy and behavioural genetics converge to present a vision of the world where health, illness and behaviour can be seen in increasingly biological rather than social terms. This new genetic paradigm has a powerful allure, but is deeply flawed. Technologies are artefacts invented by people to achieve certain goals, they are the products of creative work and shaped by the society they develop in. They are not stumbled upon by value-free science. Biology is not destiny and the vast majority of health problems in our society can be prevented through effective social policy and collective action.