Assessment & Screening Flashcards
What does NIPD stand for?
Non-invasive prenatal diagnosis
What is NIPD used to detect?
Free foetal DNA in maternal serum - detects male pregnancies (for x-linked recessive conditions) or detects fathers mutation
In screening tests, what is sensitivity?
Few false negatives
In screening tests, what is specificity?
Few false positives
What is PGD?
Pre-implantation diagnosis = one or sometimes two cells removed from 6-10 day old embryo for genetic testing
Which two chromosome analysis methods can be used in to determine PGD?
QF-PCR (for aneuploidy)
FISH
What are the pros of PGD?
Permits implantation of unaffected embryos
Termination therefore unnecessary
What are the cons of PGD?
Long wait
Not widely available
Multiple tests/procedures
What prenatal screening tests are available for detecting down syndrome?
CUB (1st trimester)
Ultrasound for increased nuchal translucency
Which conditions can be picked up by neonatal screening tests?
PKU & MCADD (by mass spectrometry)
Congenital hypothyroidism & CF (by immune-assay)
Sickle cell (by HPLC)
Which conditions can be detected by postnatal screening tests?
Tay sachs disease & Thalassaemia
When are prenatal genetic diagnostic tests carried out?
If family history of serious disorder OR a high risk from a prenatal screening test
What two prenatal genetic diagnostic tests are there?
Chorionic villous sampling (10-12w)
Amniocentesis (16-18w)
