2.7 Testing for CF Flashcards
Newborn testing
Test for elevated levels of the protein trypsinogen in the blood.
part of the Newborn Blood Spot Screening Programme for all babies in the UK
Genetic screening/testing
Procedure that allows the identification of cells or individuals with a particular DNA sequence.
Used to:
confirm a diagnosis
identify carriers
testing embryos
Prenatal genetic testing
amniocentesis
Chorionic villus sampling
Non-invasive prenatal diagnosis
Amniocentesis
A way of obtaining cells from a developing fetus. A developing fetus is wrapped in a membrane called the amnion. The space between the amnion and the fetus is filled with a fluid called amniotic fluid. Amniotic fluid contains some fetal cells. These cells can be examined and their chromosomes observed or the DNA that they contain may be investigated.
Usually carried out at around 15-17 weeks of pregnancy.
1% risk of miscarriage
Chorionic villus sampling
Procedure in which a small sample of placental tissue (which includes cells of the fetus) is removed between 8 and 12 weeks of pregnancy and tested for genetic abnormalities.
slightly higher risk of inducing a miscarriage than amniocentesis NHS says 1-2% risk
Non-invasive prenatal diagnosis (NIPD)
Works y analysing DNA fragments in the mother’s blood plasma during pregnancy. 10-20% of the cell-free DNA is from the embryo.
It becomes detectable at about 4-5 weeks> levels are too low.
Samples collected after 7 or 9 weeks depending in the genetic tests which require differing concentrations
Ethical frameworks
- Rights and duties
- Maximising the amount of good in the world
- Making decisions for yourself
- Leading a virtuous life
Ethics
Reasoned views about why certain things are wrong and others right. There is no single ethical framework on which everyone agrees.
However, four widely used ethical frameworks use the principles of rights and duties, utilitarianism, autonomy and virtue.
Rights
Things that should nearly always be allowed. So, most people believe that humans have such rights as the right to life, the right to freedom of speech, the right to a fair trial and so on. Under certain circumstances a person may lose a right; I don’t have the right to freedom of speech if that means shouting ‘fire’ in a crowded public place when there is no fire. If someone has a right to something, it usually means that one or more people have duties to that person.
Duties
Things each of us ought to do. For example, if you have a child, you have the duty to look after him/her.
Utilitarianism
The ethical framework that holds that the right course of action is that which maximises the amount of happiness or other good in the world. If you are a utilitarian it means that while you might, for example, normally tell the truth, there could be occasions when you would believe that the right thing to do would be to lie (provided you can lie convincingly!).
Informed consent
Freely giving one’s agreement to a procedure (e.g. a surgical operation) after having received and understood all the relevant information.
Autonomy
The ability to make decisions for oneself. A person acts autonomously when such decisions can be put into effect.
Virtue
A good character trait (behaviour) to possess. Precisely what the virtues are is open to disagreement, and may vary from place to place and at different times in history. However, certain virtues, such as kindness and courage, are valued by most cultures.
Justice
Ethical principle concerned with such things as the fair distribution of resources.
