Genetics menti Flashcards
A 32 year old woman has a booking appointment with her midwife at approximately 8 weeks gestation. Which fetal genetic disorder/disorders will be discussed with the her by the midwife and can be routinely screened for?
D
How is Trisomy 21 screened in first round?
by serum markers and nuchal thickness (nucal translucancy <3.5mm is normal)
what nuchal translucancy is normal?
<3.5mm
A pregnant women receives a high risk trisomy screening result and opts to have secondary screening via Non Invasive Prenatal Testing (NIPT). Identify the correct statement….
A. NIPT had a positive predictive value of > 90%
DNA from placenta
A pregnant women has a high risk NIPT screening result for trisomy 18 at 12 weeks gestation. She and her partner want to end this pregnancy as soon as possible due to the severity of this condition. Choose the correct statement…
A- she should be offered a CVS
A pregnant women at 20 weeks gestation attends for a routine anomaly scan. A cleft lip and structural heart anomaly are detected. She has an amniocentesis which shows no evidence of Trisomy on QFPCR. What is the most appropriate next test ?
Fetal Chromosome microArray
Mutation vs polymorphism?
Mutation:
-de novo
-bigger
-affects known gene
-previously reportned same phenotype
Polymorphism
-normal parent has it
-smaller
-‘ empty’ genetic region
-previously reported as polymorphism
C
D- before you do an amniocentesis you need to know what you are testing for
B- identifying lots of unknown variants
Can detect a mutation causing a genetic disease but you have approximatly 3,000,000 polymorphisms and there is only 1 mutation
It is hard filtering and finding the mutation
A. Asses maternal wellbeing for signs of PET
A- NIPD
