In I/GCSE Biology, make sure to memorize the following points!
- It is now possible to test adults, children and embryos for a faulty allele if there is family history of a genetic disorder.
- If the test turns out positive, the individual will have to decide whether or not to have children and risk passing on the disorder.
- This is called PREDICTIVE TESTING FOR GENETIC DISEASES.
- Genetic testing can also be carried out to determine whether an adult or child can be prescribed a particular drug without suffering from serious side effects.
- TESTING AN INDIVIDUAL BEFORE PRESCRIBING DRUGS.
- E.g. certain people are highly prone to getting liver damage while taking COX-2 inhibitor drugs.
- A genetic test would ensure that only those patients who do have the prone gene are prescribed the drug.
- Embryos can be tested for embryo selection.
- The healthy embryos that do not have the faulty allele are then implanted.
- This process is called in vitro fertilisation (IVF).
- The process for embryo selection is called PRE-IMPLANTATION GENETIC DIAGNOSIS (PGD).
- After fertilisation, the embryos are allowed to divide into eight cells before a single cell is removed from each one for testing.
- The selected cell is then tested to see if it carries the allele for a specific genetic disease.
- PGD has risks including inaccuracy in results-healthy embryo not being implanted and it may also decrease the chance of the embryo surviving once it has been implanted.
RISKS OF GENETIC TESTING:
Let's look at the diagram below to have a quick revision!
However testing adults and foetuses for alleles that cause genetic disorders has implications that need to be considered, including:
- Risk of miscarriage as a result of cell sampling for the genetic test
- Using results that may not be accurate , including false positives and false negatives
- Whether or not to have children
- Whether or not a pregnancy should be terminated
- Whether other members of the family should be informed
- For example: governments may have the ability to impose genetic tests on individuals by implementing genetic screening programmes, but should they be allowed to do so?
- There is the potential for genetic testing to be used to produce detailed genetic profiles.
- These could contain information on everything from ethnicity to whether they are prone to certain conditions (e.g. obesity) or diseases (e.g. cancer).
However how will the information be used?
- Employers could potentially refuse to employ someone who possessed certain alleles
- Insurers may not cover a person who had genes that made them more likely to suffer a heart attack.
And we're done with this topic! Well Done!
Drafted by Alyssa (Biology)
- "Genetic Testing: Uses, Side Effects, Procedure, Results", https://www.verywellhealth.com/thmb/RN78ICseQvdZpXApzZLY46ZXYNI=/1500x844/smart/filters:no_upscale()/2860730_color-5babc8d9c9e77c002ccae708.png
- "Drugs". Photo from the internet.
- "In vitro Fertilisation (IVF)", https://vivaneo-ivf.com/fileadmin/user_upload/img/Infografiken/VivaNeo-IVF-eng-min.jpg
- "SciELO - Brasil - Preimplantation genetic diagnosis for cystic fibrosis", https://minio.scielo.br/documentstore/2317-6385/Bcm9qZRTRNZYjL3zfwYwr7w/bbb0d94578fb43c80fcc402b60471c5d8d2964c4.jpg
- "Risk of genetic testing". Photo from the internet.
- "Genetic Testing of Kids: Ethical Issues", https://i.ytimg.com/vi/qNW2YkWmhTA/maxresdefault.jpg