1.10 Using Genome Research In Medicine

Question 1

Why is the human genome important? (2)

Answer 1

• It helps us understand how genetic diseases work so preventative steps can be taken. People can get screened to detect health risks early and start treatment sooner
• It aids the diagnosis and treatment of inherited disorders by letting us quickly identify faulty genes. New personalised drugs and therapies can be tailored to a patient’s specific genetic makeup (this is sometimes called personalised medicine)

Question 2

How can genetic testing help to improve healthcare? (3)

Answer 2

• Some genetic variants put you at a higher risk of developing a certain disease, e.g. some types of cancer. If people knew they had a particular variant, they may be able to make lifestyle changes to reduce this risk
• In some cases, the presence of a particular genetic variant or variants meant that a person will definitely have a disease (rather than just being more likely to get it). E.g. a person will have cystic fibrosis if they have two copies of the recessive CF allele. In the UK, newborn babies are routinely tested for certain genetic variants, so doctors can tell whether or not they’ve inherited a particular genetic disorder. If they have, treatment for the disorder can begin early
• Its not known that some common genetic variants make some drugs less effective. Genetic testing for these variants could help doctors to predict how their patient will respond to specific drugs and only prescribe the ones that will be the most effective for the patient. This is called personalised medicine

Question 3

Drawbacks of genetic screening (3)

Answer 3

• Learning about their genetic risks can cause stress and mental health issues for some people
• Genetic discrimination may lead to unfair treatment in jobs and insurance for those with certain gene variants. Strict regulations are needed to prevent gene-based bias
• There are concerns about the misuse of genetic data by employers and insurers, emphasising the need for privacy protections

Question 4

In the context of the Human Genome Project, how does understanding genes contribute to the treatment of inherited disorders?

Answer 4

By tailoring treatments based on an individual’s unique genetic makeup

Question 5

How does the Human Genome Project enhance our understanding of the link between genes and diseases?

Answer 5

By mapping the entire human genome and revealing genetic variations

Question 6

How could genetic testing be used to help people with family planning?

Answer 6

A couple wanting to have a baby could use genetic testing to identify the risk of their baby having a particular genetic disorder. This could involve testing of the parents and of the embryo or fetus.

Question 7

Genetic testing for family planning (3)

Answer 7

• Parent: one of the parents may know there is a genetic disorder within their family. Even though they may not have the disorder, genetic tests could reveal whether they are a carrier for the condition
• Embryo: a couple who know they are at risk of passing on a genetic disorder may choose to have their eggs fertilised in a lab. A cell can be taken from each resulting embryo and its DNA analysed. An embryo without the genetic variants linked to the disorder can be implanted into the womb to develop into a baby
• Fetus: once a woman is pregnant, it is possible to get some of the fetal DNA by taking a sample of the amniotic fluid, which surrounds the fetus in the womb. (This procedure carries a very small risk of miscarriage.) The fetal DNA can then be tested for the genetic variants linked to the disorder. If the test is positive the couple can decide whether they wish to continue with the pregnancy

Question 8

Problems with genetic testing for family planning (2)

Answer 8

• Testing isn’t 100% perfect. E.g. a couple could receive a positive test result during pregnancy (suggesting that their unborn baby will have a genetic disorder) but the test result may be wrong, causing the couple unnecessary stress. Alternatively, a couple who incorrectly receive a negative test result may not be prepared for coping with their child’s disorder when he or she is born
• Genetic testing can lead to the destruction of embryos or a termination. Some people think that any potential life should be allowed to survive, whether disorders he or she may have. There’s also a worry that genetic testing is a ‘slippery slope’ and that there may come a point where everyone wants to screen their embryos and pick the most ‘desirable’ one