Genetic screening

Question 1

Why do some people use genetic screening?

Answer 1

• if there is a family history of a genetic disorder, individuals may use genetic screening to determine if they have a particular allele in their genome

Question 2

What is IVF? What does it stand for?

Answer 2

• IVF, in vitro fertilisation is a type of fertility treatment during which fertilisation is carried out in the lab

Question 3

What does pre-implantation genetic diagnosis (PGD) involve? How is DNA analysed? What is a disadvantage?

Answer 3

• PGD involves analysis of the DNA of an embryo prior to implanting it into the uterus
• the sample of DNA to be analysed can be obtained by taking cell samples from embryos produced during IVF
• disadvantage is its expensive

Question 4

What are the benefits of IVF and PGD?

Answer 4

• reduces the chances of having a baby with a genetic disorder
• it avoids abortion as it is carried out before implantation of the embryo

Question 5

What does chorionic villus sampling (CVS) involve? When is it carried out? What is the chance of miscarriage?

Answer 5

• CVS involves removing and testing a small sample of cells from the placenta using a fine needle
• the cells contain foetal DNA which can be analysed for genetic disorders, allowing parents to make informed decisions about the pregnancy and foetus
• it is carried out at around 8-12 weeks of pregnancy
• the process has a 1-2% risk of miscarriage

Question 6

What does amniocentesis involve? How is DNA analysed? What is the chance of miscarriage?

Answer 6

• amniocentesis involves removing and testing a small sample of cells from amniotic fluid using a fine needle
• the amniotic fluid is the fluid that surrounds the foetus within the uterus
• the fluid contains foetal cells which contain DNA to be analysed
• it is carried out at around 15-17 weeks of pregnancy
• the procedure has a 1% risk of miscarriage

Question 7

What are the benefits of CVS and amniocentesis?

Answer 7

• tests allow parents to make informed decisions
• results can help parents to prepare for the future care of the child, including medical treatment

Question 8

What does NIPD stand for? How does it work?

Answer 8

• NIPD stands for non-invasive prenatal diagnosis
• this works by analysing DNA fragments in the mothers blood plasma during pregnancy

Question 9

What does implantation mean?

Answer 9

• the stage of human reproduction at which the embryo attaches to the wall of the uterus

Question 10

What are the arguments against genetic screening

Answer 10

• its expensive
• it implies that offspring with genetic problems are undesirable, this could lead to prejudice
• PGD could lead to ‘designer babies’, embryos could be selected for more than just health, e.g. eye colour
• CVS has an increased risk of miscarriage

Question 11

What are arguments for genetic screening?

Answer 11

• it helps to stop people suffering from genetic disorders
• treating disorders costs the government and taxpayers, so screening could reduce healthcare costs
• parents have time to prepare for a child with a genetic disorder or decide to have an abortion