Prenatal Diagnosis and Counseling Flashcards
1
Q
What is Sensitivity in genetic screening?
A
- The ability to identify affected individuals
2. Measured as PROPORTION OF TRUE POSITIVE
2
Q
What is Specificity in genetic screening?
A
- The ability to identify unaffected individuals
2. Measured as the PROPORTION OF TRUE NEGATIVE
3
Q
What are 2 major types of genetic diagnosis?
A
- Direct testing (The known mutation for diseases are examined directly in suspicious cases)
- Indirect testing: “linkage analysis” (Is used when the gene cannot be directly identified but can be located within a specific region of a chromosome)
*Indirect genetic analysis used genetic markers RESTRICTION FRAGMENT LENGTH POLYMORPHISM (RFLPs) and SHORT TANDEM REPEAT POLYMORPHISM (STRPs)
4
Q
What is Maternal Age?
A
- Maternal age 35 or older at time of delivery; increased risk for chromosome abnormalities
5
Q
What are 4 prenatal testings/screenings?
A
- Multiple marker screening
- Ultrasound-12 to 20 weeks
- CVS- 9.5 to 12.5 weeks (Chorionic Villus Sampling)
- Amniocentesis-14 to 20 weeks (third trimester)
- Maternal serum hormone levels:
a. alpha-fetoprotein
b. beta-HCG (Lower amount of beta-HCG will be expected in case of threatened abortion)
c. Estriol
6
Q
What is Canavan disease?
A
- Spongy degeneration of the brain
- Aspartoacylase deficiency
- Inherited condition that affects the breakdown and use (metabolism) of aspartic acid
7
Q
What is Dysautonomia?
A
- Autonomic dysfunction
2. Is a broad term that describes any disease or malfunction of the autonomic nervous system
8
Q
What are the Markers for T21 (Down Syndrome)?
A
- Low AFP
- High hCG
- Low uE3 (estriol)
- High Inhibin-A
9
Q
What are the Markers for T18 (Edward Syndrome)?
A
- Unchanged AFP
- Very low hCG
- Low uE3
- Unchanged Inhibin-A
10
Q
What are the Markers for T13 (Patau syndrome)?
A
- Increase AFP
- Normal hCG
- Normal uE3
- Normal Inhibin-A
11
Q
What are the Markers for Turner Syndrome?
A
- Decrease AFP
- Very high hCG
- Decrease uE3
- Very high Inhibin-A
