Chromosomal Defects Flashcards Preview

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Flashcards in Chromosomal Defects Deck (120)
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1

Invasive testing by amniocentesis, chorionic villous sampling, or cordocentesis is associated with a risk of miscarriage of about ___%.

1

2

U/s screening is based onthe fact that most fetuses with chromosomal abnormalities have...

major structural malformations or minor 'markers'

3

The risk for many of the chromosomal defects increases with...

age.

4

Major chromosomal defects are associated with...

1. multiple antomic abnormalites
2. mental limitations
3. high mortality rate

5

Genetic disease may be the result of...

1. abnormal # of chormosomes
2. abnormal structure of chromosomes
3. single gene defect (dominant or recessive)

6

The probablity of passing on a dominant genetic trait to your offspring is...

50%

7

The probablity of passing on a recessive genetic trait to your offspring is...

25%

8

This is the complete set of chromosomes in a cell, often arranged in pairs for analysis.

karyotype

9

This is a normal balanced set of chromosomes.

euploid

10

This is an unbalanced set of chromosomes.

aneuploid

11

This is the presence of an extra chromosome.

trisomy

12

This is the entire physical and physiologic makeup of an individual determined both geneticlly & environmentally.

phenotype

13

This is the genetic composition of an individual.

genotype

14

What increases the risk of trisomy?

1. older mother
2. previous trisomy (another .75%)

15

A major congenitial anomaly is found in...

3:100 births.

16

__% births are complicated by minor birth defects.

10-15

17

In the first trimester chromosomal abnormaliites are determined by...

1. nuchal translucency
2. free beta-hCG and PAPP-A
3. CVS-Chorionic Villus Sampling

18

This scan measures the fluid filled area at the back of the neck between 11.5 - 13.5 weeks.

nuchal translucency

19

The nuchal translucency scan measures the fluid filled area at the back of the neck between __ weeks.

11.5 -13.5

20

Low levels of beta-hCG and PAPP-A may indicate...

1. abnormal implantation
2. poor placental development
3. a risk for trisomy 18

21

The blood test and the nuchal translucency together can detect about ___ of fetuses with Downs and Edwards.

85%

22

When abnormal blood tests and translucencies are obtained, patient's are offered...

a CVS to determine chromosomal defects.

23

T/F? Neural tube defects can be diagnosed with CVS.

FALSE, cannot

24

A CVS is performed between ___ weeks.

9-12

25

Results from CVS are usually back in ___ days.

2-3

26

In the 2nd and 3rd trimester, chromosomal abnormalities are determined by...

1. multiple marker screening
2. amniocentesis

27

These biochemical screening tests have been developed to find fetal anomalies.

multiple marker screening

28

This test screens for a protein normally produced by the fetal liver.

MS-AFP

29

This test screens for a hormone produced within the placenta.

hCG

30

This test screens for an estrogen produced by both the fetus and the placenta.

uE3 (unconjugated estriol)