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Changing genesTesting and counselling The genes in each of our cells are the inherited blueprint for life. They contain the code that controls the way our bodies develop – though they're not the end of the story. What we are, physically and mentally, is also affected by the experiences we have. So, for example, you might have hearing loss because you've spent the last 20 years as a drummer in a metal band. Or you might have been born deaf because of the genes you inherited. Or you might have a condition in which both genetic and environmental factors are involved. Huge strides have recently been made in genetics, and scientists have identified genes associated with many different conditions, including certain forms of deafness. But continuing advances in knowledge, as well as research into possible treatments, are creating dilemmas for the Deaf community. Above all they pose the question: is deafness something that we want to 'correct' or eliminate? This week VEE-TV confronted this controversial issue. Testing and counsellingAs the genes involved in certain conditions are identified, tests can be developed to tell whether or not individuals have those genes, so parents can be advised about their chances of having children that are affected. This is already true of certain types of deafness. There are obvious benefits of testing, such as enabling parents to prepare for having a deaf child. But if tests are carried out on the parents, there will still be uncertainty because of the complex ways in which genes combine. Heather and Philip Gerrard, for instance, were told that they had a 50:50 chance of having a deaf baby. 'Really that wasn't anything new to us,' Philip says. However, it is possible to carry out certain tests on the foetus in the womb, which give much more definite results (though such tests are currently not available in the UK). But this raises an even bigger concern. Might tests lead to the abortion of deaf children? Anna Middleton, a genetics counsellor at Addenbrooke's Hospital, Cambridge, thinks not. 'The aim of genetic counselling is not to wipe out all disability from society,' she says. 'It's simply to offer information and support to individual families.' Anna thinks that most people are 'appalled' at the idea of aborting a foetus because the child would be deaf. Jane Newman, a professional in deaf genetics, stresses the importance that is placed on appropriate training for counsellors. 'The BDA [British Deaf Association] and Deaf community think that genetic counsellors should be deaf-aware,' she says, 'so when they see someone who doesn't have that awareness, they can help them to feel positive and confident about keeping their deaf child.' Anna Middleton says that she hopes to employ genetic counsellors who are themselves deaf. TherapyThe prospect of developing genetic treatments to 'correct' deafness is also a very controversial issue. There are two possible approaches to gene therapy. One, called 'somatic' therapy, affects only the individual on which it is used. Somatic therapy might involve introducing genetic material into the body to compensate for an individual's missing or 'non-functioning' gene. Or, in some cases, knowledge of a specific change associated with a particular form of genetic deafness night be treated with a protein or a drug. The other approach, 'germ-line' therapy, would take place in egg or sperm cells before fertilisation, altering the genetic code so that deafness could not be passed on to the next generation, and affecting the genetic make-up of subsequent generations. Germ-line therapy is currently illegal in the UK and widely elsewhere, and in any case practical techniques of this sort are a long way in the future. The BDA opposes all germ-line therapy, and supports somatic therapy only in adults, who can make the choice for themselves. 'The BDA supports the internationally widespread ban on germ-line gene therapy in humans,' the BDA policy statement says. 'We would respect the right of deaf adults to make use of somatic therapies were these to become available, but we would not support the use of such therapies on deaf children.' Jane Newman says that somatic therapies would be particularly helpful in certain circumstances, including where deafness is associated with other problems, such as in Usher syndrome, and for people who become deaf later in life and so find it harder to adapt. Suzanne Rodaway, a student and mother, agrees: 'Parents could say, "I don't mind if my child is deaf, and I can have the other conditions switched off." So the child is just born deaf, with no other medical problems, and will grow up happy.' Values and regulationSo are we heading for a world in which people try to eradicate differences caused by what are considered 'defective' genes – however unrealistic that goal may be? Or will our knowledge be used to increase individual choice and ensure that we do our best to give people equal opportunities? The way gene therapy and gene testing is regulated will be crucial. 'Biotechnology poses an enormous challenge to the Deaf community,' the BDA policy statement says. 'Decisions about the use and regulation of genetic technologies relating to deafness do not just affect future generations of Deaf people, they say something about the value we place on Deaf people's lives today. Such decisions will determine the kind of society we live in – a society that seeks relentlessly to assimilate minorities, or a society that celebrates difference and diversity.' So what do you think? Have your say on the message board now. Help and infoAbout.com: deafness BDA policy statements Cracking the Code Defeating Deafness Genetic Engineering and Its Dangers Genetics of congenital hearing impairment Human Genetics Alert Human Genetics: The Deaf Community's View Human Genome Project Institute for Human Gene Therapy National Human Genome Research Institute (NHGRI) Nuffield Council on Bioethics ScienceNet Secrets of Life UK Human Genetics Commission Your Genome
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