Gene Technology and Ethics
When Science Meets Society
In 2001, a couple discovered through genetic testing that one of them had inherited the allele for Huntington’s disease — a dominant, inherited condition that causes progressive brain damage, typically appearing in mid-life. They wanted children but feared passing the condition on. With the help of a specialist fertility clinic, embryos created outside the body were tested before implantation. Only embryos free of the allele were selected. Their daughter was born healthy and has no risk of inheriting Huntington’s from this allele.
This case illustrates the power and the complexity of modern gene technology. The science is real, the benefits can be life-changing — and the ethical questions it raises are genuinely difficult. This lesson walks through the key applications and the framework scientists and society use to weigh them.
Genetic Testing
Genetic testing can be carried out at different stages of life and for different purposes. Carrier testing identifies adults who carry a recessive allele for a condition such as cystic fibrosis or sickle cell anaemia, even though they are unaffected themselves. It helps couples understand their risk before having children. Predictive testing identifies whether someone carries an allele that will (or is likely to) cause a condition later in life, such as Huntington’s disease. Diagnostic testing confirms or rules out a suspected inherited condition after symptoms appear.
Genetic testing during pregnancy can be done by sampling foetal cells from the amniotic fluid (amniocentesis) or from the placenta (chorionic villus sampling). These tests carry a small risk to the pregnancy and are offered when there is an identified reason to suspect an inherited condition.
Genetic testing includes carrier testing (identifies carriers of recessive alleles), predictive testing (identifies future disease risk) and diagnostic testing (confirms a suspected condition). Each has genuine benefits and genuine risks that must be weighed carefully.
Embryo Screening — Pre-implantation Genetic Diagnosis
Pre-implantation genetic diagnosis (PGD) allows couples who are carriers of serious genetic conditions to have children free of those conditions. Embryos are created outside the body using in vitro fertilisation (IVF). A cell is removed from each embryo at an early stage and its DNA is tested. Embryos that carry the faulty alleles are not implanted; those free of the condition are selected for implantation.
PGD is currently used in the UK for serious conditions including cystic fibrosis, Huntington’s disease, and certain chromosomal conditions. It is regulated by law — only conditions meeting defined criteria of seriousness can be screened for.
Benefits: Prevents the birth of children with serious, life-limiting conditions. Reduces suffering for affected individuals and their families. Enables people who carry genetic conditions to have biological children they might otherwise choose not to have. Reduces long-term healthcare costs associated with managing serious inherited conditions.
Risks and concerns: IVF itself carries medical risks for the woman (hormonal stimulation, procedure risks). Unused embryos are destroyed — people who believe life begins at fertilisation see this as morally problematic. There is a risk of ‘designer baby’ concerns: if embryo selection is permitted for medical conditions, could it slide towards selecting non-medical traits such as intelligence or appearance? This ‘slippery slope’ argument is taken seriously by many bioethicists. Some disability advocates argue that selecting against certain conditions implies that lives lived with those conditions are less valuable.
When weighing these considerations, scientists, regulators and individuals use a process of risk-benefit analysis under uncertainty. The decision is not purely scientific — it involves values, personal beliefs and social priorities alongside the evidence. This is why regulatory bodies include ethicists, patient representatives and lay members alongside scientists.
Gene Therapy
Gene therapy aims to treat or cure genetic conditions by delivering a working copy of the faulty gene into the patient’s cells. If the cells can then produce the normal protein, the symptoms of the condition are reduced or eliminated. Two main approaches exist:
Somatic gene therapy targets the body (somatic) cells of the patient. Any changes affect only that individual and are not passed on to children. This is the approach currently used in clinical trials and approved treatments. Germline gene therapy would target eggs, sperm or early embryos, meaning any changes would be inherited by future generations. Germline editing in humans is not permitted in the UK and most countries because the safety and ethical implications are not yet understood.
Somatic gene therapy targets body cells and affects only the patient. Germline gene therapy would affect all future generations and is not currently permitted in the UK due to unresolved safety and ethical concerns.
GM Crops and Agricultural Gene Technology
Genetically modified (GM) crops have had genes from other organisms introduced into their genome. A well-known example is Golden Rice, which has been engineered to produce beta-carotene (a precursor of vitamin A) in the grain, because rice does not naturally do this. Vitamin A deficiency is a serious public health problem in parts of the world where rice is the dietary staple. GM crops in general are also engineered for resistance to specific herbicides or insect pests, which can reduce pesticide use and increase yields.
Arguments in favour of GM crops: Could address vitamin deficiency and malnutrition in developing countries. Herbicide-resistant crops reduce the number of spraying applications needed. Higher yields can reduce pressure to clear new land for agriculture, potentially benefiting biodiversity. Peer-reviewed scientific consensus generally considers currently approved GM crops to be safe for consumption.
Arguments against GM crops: Modified genes could spread to wild plant relatives through cross-pollination, potentially creating herbicide-resistant weeds (‘superweeds’). Effects on non-target organisms (insects, birds) in the ecosystem are not always fully understood before release. Large seed companies that own GM seed patents could gain disproportionate economic power over farmers. Public trust is difficult to rebuild if problems emerge after widespread adoption. Some religious and cultural viewpoints object to ‘playing God’ by altering life at the genetic level.
Evaluating the GM debate well means distinguishing between claims that are supported by scientific evidence (e.g. peer-reviewed safety studies on specific approved crops) and claims that are ethical or value-based (e.g. concerns about corporate power or religious views). Both types of concern are legitimate inputs to a policy decision — but they carry different kinds of weight.
Making Ethical Decisions in Science
When scientists, governments and the public decide whether to permit a technology like PGD, gene therapy or GM crops, they rarely reach a consensus based on evidence alone. Ethical decision-making in science involves weighing the scientific evidence (does it work? what are the risks?) alongside values (what kind of society do we want? whose interests count?) and practicalities (who will have access? who bears the costs?).
In your exam, questions about gene technology and ethics will often ask you to ‘evaluate’ or ‘discuss’. This means presenting both the case for and the case against a technology, using scientific reasoning, and reaching a reasoned conclusion. Simply listing benefits without acknowledging risks, or dismissing a technology without engaging with its evidence base, will not reach the top marks.