Ante And Postnatal Screening Flashcards
What is the point of antenatal screenings
Assess the health of the embryo before birth to detect disorders like Down syndrome
What is a karotype
It is a photo of an individuals chromosomes arranged in homogulous pairs and if there is an extra copy of a chromosome it could be an indicator of Down syndrome
What is the point of an ultrasound
To determine age of foetus and identify any physical developments of limbs etc that are unusual
What is a biochemical test
It detects any marker chemical that may be unusual e.g.: HCG may remain high but no Down syndrome “false positive result”
What is an amniocentesis
They put an needle in the stomach and draw amniotic fluid down then out in a culture dish to karotype
Is done later but risk of miscarriage
What is chorionic villus sampling
Suction tube through cervix and draw fluid and karotype this can be done earlier but risk of miscarriage
Explain rhesus antibody testing
It occurs when the mother is rhesus negative and the father is rhesus positive. Not an issue for the first child but as fluids don’t touch but body will produce antibodies against the rhesus positive child so mothers but be given anti rhesus antibodies
When does post natal screening take place and what is the purpose
Health check after birth to detect any conditions like PKU, test this by the heel prick test. Special diet required
What is the point of pedigree charts
To see if a pattern of inheritance can be found and construct a family tree
Definition and example of autosomal recessive
Cystic fibrosis
Effects makes and females equally
Could carry but not be affected
May skip generations
Example of autosomal dominant
Huntingtons disease
Male and female equally
Cannot Carry without being affected
Example of autosomal incomplete dominance
Sickle cell disease
Make and females equally
Carriers have it but less severe
Example of a sex linked
Haemophilia
Makes more affected as fathers can’t carry it pass it but females can carry it
