Ante and Post-Natal Screening Flashcards
What are alleles?
Different forms of a gene
Define the term ‘carrier’
A person who has inherited a recessive allele for a genetic trait
or mutation but usually does not display that trait or show
symptoms of the disease
What are autosomes?
Any chromosome that is not a sex
chromosome
State the sex chromosomes of
a) males and b) females
a) XY
b) XX
Give an example of a genetic
disorder detected by analysing a
blood sample shortly after birth
Phenylketonuria (PKU)
State the cause of phenylketonuria
(PKU)
A substitution mutation
-causes the enzyme that converts
phenylalanine to tyrosine to be
non-functional
What advice is given to those
diagnosed with PKU?
Placed on a restricted diet with low
phenylalanine/protein
What is antenatal screening?
tests used to identify the RISK OF A DISORDER
-further tests and pre-natal
diagnosis may be offered
Name two ultrasound imaging scans
offered to pregnant women
Dating and anomaly scans
Describe the purpose of a dating scan
Determine pregnancy stage and the
due date.
When is a dating scan carried out
8-14 weeks
Describe the purpose of an anomaly
scan
To detect physical abnormalities in the foetus
When is an anomaly scan carried out
18 and 20 weeks
Why are routine blood and urine
tests carried out throughout
pregnancy?
To monitor the concentration of
marker chemicals
What happens if an atypical chemical concentration arises?
Diagnostic testing can be carried out
to determine if the fetus has a
medical condition
