U.2 K.A-4 Ante- And Postnatal Screening

Question 1

Name the technique by which high-frequency sounds are bounced off the fetid and converted to an image on a computer screen

Answer 1

Ultrasound imaging

Question 2

Name two scans that are produced through ultrasound imaging

Answer 2

Dating scan and anomaly scan

Question 3

When is a dating scan produced

Answer 3

8-14 weeks

Question 4

What does a dating scan show

Answer 4

Stage of pregnancy and due date

Question 5

When is an anomaly scan carried out

Answer 5

18-20 weeks

Question 6

What does an anomaly scan show

Answer 6

Serious physical abnormalities in the fetus

Question 7

Name a maker chemical that doctors check for the level of in a mothers urine/blood

Answer 7

HCG hormone or AFP

Question 8

If the levels of these marker chemical are checked at an inappropriate point in the timeline and found to be high/low, this could lead to what two types of false alarm

Answer 8

False positives and false negatives

Question 9

If a fetus is wrongly diagnosed as having a condition when it doesn’t then this is what type of mistake

Answer 9

False positive

Question 10

If a fetus is wrongly diagnosed as not having a condition when is actual fact it does, then this is what type of mistake

Answer 10

False negative

Question 11

What name is given to the type of tests where they look at marker chemical levels and other indicators that look for signs and symptoms of a disorder

Answer 11

Screening test

Question 12

What name is given to a definitive test that established without doubt that the fetus has a disorder. It is usually carried out following concerns after a screening test

Answer 12

Diagnostic test

Question 13

Name two diagnostic tests

Answer 13

Amniocentesis and Chorionic Villus sampling

Question 14

Both diagnostic tests allow the collection of some of the baby’s cells and a photograph of the chromosomes all laid out. What name is given to the visual display of chromosomes

Answer 14

Karyotype

Question 15

When is amniocentesis carried out

Answer 15

14-16 weeks

Question 16

When are the cells taken from during amniocentesis

Answer 16

Amniotic sac

Question 17

What is the negative aspect of amniocentesis

Answer 17

Risk of miscarriage

Question 18

When is CVS carried out

Answer 18

As early as 8 weeks

Question 19

Where are the cells for CVS taken from

Answer 19

The chorionic villus of the day placenta

Question 20

What are the advantages of CVS over amniocentesis

Answer 20

CVS carried out earlier in a pregnancy and if there is any problem, then a termination can be considered much earlier when it is less traumatic. If parents wait until 14-16 weeks as with amniocentesis, then it is much more traumatic

Question 21

What name is given to the charts used by genetic counsellors to assess the degree of risk in passing on a genetic disorder to children

Answer 21

Pedigree charts/family tree

Question 22

What does a line through a symbol on a pedigree chart show

Answer 22

That the person has died

Question 23

Which symbol is used to represent a female

Answer 23

A circle

Question 24

Which symbol is used to represent a male

Answer 24

A square

Question 25

What pattern of inheritance is shown when a condition carried on the autosomes has it relatively rarely expressed, skips generations and occurs more between members joined by a consanguineous marriage (too close in relation to each other)

Answer 25

Autosomal recessive inheritance

Question 26

What pattern of inheritance is shown when a condition carried on the auto dome appears every generation? Each person affected has a parent who suffered the condition and once the condition is lost form a branch to f the tree it is lost altogether from the branch

Answer 26

Autosomal dominant inheritance

Question 27

What pattern of inheritance is shown when both alleles are expressed together and this is the most common phenotype, the number of males and females affected in equal numbers

Answer 27

Autosomal incomplete dominance

Question 28

What pattern on the inheritance is shown by a condition carried on the sex chromosomes, where many more males than females are affected and non of the affected males have sons with the trait

Answer 28

Sex-linked recessive inheritance

Question 29

Name a condition whereby a baby is unable to change the amino acid Phenylalanine into tryrosine

Answer 29

Phenylketonuria

Question 30

When is the test for phenylketonuria carried out in babies

Answer 30

A few days after birth

Question 31

What name is given to the type of testing that occurs in babies after they are born

Answer 31

Postnatal screening