Prenatal And Postnatal Genetic Screening Karamursel IMP Flashcards
What are the single gene disorders?
Cystic fibrosis
Tay-sacs
Which diseases are classified as Trisomy?
Down syndrome(trisomy 21)
Edward syndrome (trisome 18)
Patau syndrome (trisomy 13)
What are the indications for diagnostic test?
-inc resutls in screening test
-pervious preg affected by fetal chromosomal abnormality
-balance translocation in one of the parenst
-congemital cardiac defect in one of the parent
-congenitally defective previous pregnancy
What are the list of non-invasive or screening tests?
Ultrasound
Fetal MRI
Free fetal DNA
What are the list of invasive or diagnostic tests?
Amniocentesis
Chorionic villus sampling
Fetal blood sampling
Fetal biopsy
Fetal surgery
Cordocentesis
What is Nuchal translucency test?
Component of ‘double test’ , it collects the fluid found under the thickness of the fetus’ neck on a sagittal section.
What happens when nuchal translucency measure is high?
The double test will show risk for down syndrome
When is nuchal translucency fluid test measured?
During the first trimester (12wk) bcz it is a transient finding and the fluid may disappear in the 3rd trimester
What are the u/s markers for trisomy 21
-Nuchal translucency(increase in fluid)
-Fetal nasal bone(no/short nasal bone)
-hyper-ecogenic cardiac focus(baby’s heart seems normal but on u/s detection of spark on heart)
-Pelvic Cholectesis(fluid collection in the renal pelvis)
-Low Alpha Feto protein
Which tests can detect spina bifida?
Alpha feto protein test
Alpha feto protein is diagnostic or screening test?
Screening test
When is alpha feto protein test done during pregnancy?
Between 14-20 weeks
It is a component of triple test
An increase in alpha feto protein indicates also…?
Abdominal wall defect(omphalocele& gastroschisis)
+spina bifida
+neural tube defect
What decreases Alpha feto protein?
Chromosomal trisomy (down syndrome or edward)
-gestational trophoblastic
-fetal death
What are the reasons for false positive Alpha Feto protein
-Overestimated gestational age
-Gestational diabetes
-twin triplet pregnancies
-intrauterine growth restriction
-bleeding during pregnancy
