Ante- And Postnatal Screening

Question 1

What does antenatal screening do?

Answer 1

• identifies risks of a disorder so further tests an be carried out and prenatal diagnosis given

Question 2

What are the different types of ultrasound scans?

Answer 2

• dating scan

- anomaly scans

Question 3

What is a dating scan?

Answer 3

• a dating scan checks for due date
• is used in conjunction with testing for marker chemicals
• carried out 8-14 weeks

Question 4

What is an anomaly scan?

Answer 4

• anomaly scans can detect serious physical abnormalities

- carried out 18-20 weeks

Question 5

What do blood and urine tests do?

Answer 5

• they check for different chemical markers which may vary during pregnancy
• an atypical chemical concentration can lead to a diagnostic test to determine presence of a medical condition
• if it is carried out at the wrong time it can result in a false positive

Question 6

What is diagnostic testing?

Answer 6

• cells taken from the samples can be cultured to produce a karyotype (shows as an individual’s chromosomes arranged as homologous pairs) to help diagnose a range of conditions

Question 7

What are the two types of diagnostic tests?

Answer 7

• amniocentesis

- chronic villus sampling (CVS)

Question 8

What is the differences between amniocentesis and CVS?

Answer 8

• amniocentesis is when cells are taken from the amniotic fluid and CVS is cells taken from the placenta
• amniocentesis has a lower chance of miscarriage than CVS but can only be carried out later in the pregnancy

Question 9

Autosomal ressesive

Answer 9

• expressed rarely

- skips generations

Question 10

Autosomal dominant

Answer 10

• expressed in every generation
• every sufferer has an effected parent
• when it fails to appear in a generation it dies out

Question 11

Autosomal incomplete dominant

Answer 11

• fully expressed form occurs rarely
• partially expressed form is much more common
• every fully expressed sufferer has two partially expressed parents

Question 12

Sex linked

Answer 12

• XX XY
• effects more males than females
• passed mother to son

Question 13

What is phenylketonuria (PKU) testing?

Heel prick

Answer 13

• testing for PKU, a substitution mutation which causes the enzyme which converts to phenylalanine to tyrosine to be non-functional
• sufferer are placed on a restricted diet