Chromosomal Abnormalities

Question 1

diploid

Answer 1

a cell having the normal pair of each chromosome
normal cells are diploid
except gametes

Question 2

haploid

Answer 2

a cell having only one member of each pair of chromosomes

Question 3

monosomy

Answer 3

a cell having only one of an individual chromosome

Question 4

mosiac (cells)

Answer 4

a situation in which some cells have an abnormal number of chromosomes, others do not

Question 5

anomaly

Answer 5

a structural difference that differs from the norm

Question 6

triple screen

Answer 6

maternal blood test in the 2nd tri. to detect chromosomal abnormalities

1. AFP (produced by yolk sac and fetal liver)
2. estriol (produced by placenta)
3. hCG (produced by placenta

Question 7

quadruple screen

Answer 7

done at 16 wks gest.
detects down's syndrome
the triple screen plus 2 proteins
1. PAPP-A (produced by placenta)
2. dimeric inhibin A (produced by placenta)

Question 8

chorionic villi sampling (CVS)

Answer 8

10-12 wks gest.
earliest procedure
1. transvag.
2. transabd

Question 9

amniocentesis

Answer 9

16 wks gest.
evalute AFI
look for MVP
extremely accurate
takes longer for results
done in mothers with advanced maternal age

Question 10

cordocentesis

Answer 10

PUBS
percutaneous umbilical cord blood sampling
17 wks. gest.
rapid results
tests for Rh sensitization

Question 11

abnormal lab values for a fetus with Trisomy 21

Answer 11

low AFP
low Estriol
^ hCG
^ inhibin A
low PAPP-A

Question 12

lab values for edwards syndrome

Answer 12

(trisomy 18)

all lab values are decreased

Question 13

what is typically found with a triploidy fetus

Answer 13

partial molar pregnancy
^ hCG
bilateral theca lutein cysts

Question 14

CVS

Answer 14

10-13 wks gest
carries most risk for fetal death
chorionic villi = in the primitive placenta a.k.a. “chrionic frondosum”