200- repro genetics

Question 1

advantages and disadvantages of CVS compared to amniocentesis

Answer 1

can be done earlier but results can be skewed by confined placental mosaicism

Question 2

what does increasing maternal age increase the risk of? (what kind of mutations)

Answer 2

autosomal and sex chromosome aneuploidies but not polypoidies (triploides) or microdeletions

Question 3

what is the majority of down’s syndrome a consequenc of? what else can cause it

Answer 3

maternal non disjunction. robertsonian translocation

Question 4

what is the quad screen? what do results show in down’s?

Answer 4

AFP, unconjugated estriol, hCG, inhibin A.

In down’s, AFP and uE3 are low while hCG and inhibin A are high

Question 5

what is massive parallel sequencing

Answer 5

can take a sample of mom’s serum, see what proportion is from chromosome 21 or 18 and detect aneuploidy

Question 6

two types of arrays? which can detect aneuploidy?

Answer 6

array comparitive genomic hybridization (aCGH) and SNP array (SNP detects aneuploidy)