Prenatal Testing

Question 1

What 3 things are screened?

Answer 1

Down’s Syndrome (T21), Edward’s syndrome (T18), Patau Syndrome (T13).

Question 2

Name 2 sampling methods

Answer 2

Chorionic villus sampling and amniocentesis

Question 3

When is chorionic villi sampling done?

Answer 3

11-14 weeks

Question 4

When is amniocentesis done?

Answer 4

15+ weeks

Question 5

Name 3 diagnostic techniques

Answer 5

FISH, microarray-based comparative genomic hybridization (aCGH) and QF-PCR

Question 6

What does FISH stand for?

Answer 6

Fluorescence in situ hybridization. Technique that uses fluorescent probes that bind to only those parts of the chromosome with a high degree of sequence complementarity.

Question 7

How does Microarray-based comparative genomic hybridization work?

Answer 7

It compares two genomic DNA samples arising from two sources, which are most often closely related. They are labelled green and red, and compete for hybridisation to their locus of origin on the chromosomes. The green to red fluorescence ratio measured along the chromosomal axis represents loss or gain of genetic material in the tumour at that specific locus.

Question 8

How does the Quantitative Fluorescence-Polymerase Chain Reaction work?

Answer 8

Quantitative Fluorescence-Polymerase Chain Reaction. Used to amplify specific regions of DNA and quantify the amount of DNA present in those region to detect the presence of additional chromosomes (aneuploidy) in patients.

Question 9

3 clinical features of perinatal depression

Answer 9

Anhedonia (lack of joy in pregnancy), lack of interest and low mood.

Question 10

What does QF-PCR stand for?

Answer 10

Quantitative Fluorescence-Polymerase Chain Reaction.

Question 11

What does aCGH stand for?

Answer 11

Microarray-based comparative genomic hybridization.