Screening and Assessment of Genetic Disorders Flashcards Preview

1. Medical Genetics > Screening and Assessment of Genetic Disorders > Flashcards

Flashcards in Screening and Assessment of Genetic Disorders Deck (3)
Loading flashcards...
1

Describe the basis of pre-implantation genetic diagnosis (PGD).

1. 1-2 cells are removed from the embryo at around 3 days, when the embryo has 6-10 cells

2. Genetic tests are carried out on the cells, including FISH, PCR, QF-PCR etc.

3. Only healthy embryos are then implanted back into the woman (up to 2 at a time)

2

Discuss the advantages (1) and disadvantages (4) of pre-implantation genetic diagnosis (PGD).

ADVANTAGES:
-Termination not necessary because all embryos are healthy

DISADVANTAGES:
-Long waiting times
-Not available to all women
-Multiple visits and procedures needed
-Take home baby rate less than 50%

3

Give 2 examples of prenatal diagnostic tests.

When are these tests done?

How long do the results for each take?

What is the miscarriage rate?

Chorionic villous sampling
When: 10-12 weeks
Results: <1 week
Miscarriage: 1 in 50

Amniocentesis
When: 16-18 weeks
Results: 1-2 weeks
Miscarriage: 1 in 100