GM 04: Population/Prenatal Screening

Question 1

T/F: Screening can be justified, despite treatment options for disorder.

Answer 1

False

Question 2

The (X) of a disease should be high to justify cost-benefit of screening.

Answer 2

X = prevalence

Question 3

Screening tests should be “accurate” in terms of which three characteristics?

Answer 3

1. Sensitivity
2. Specificity
3. Predictive value

Question 4

Good screening tests have (high/low) specificity. If not, you get false (positive/negative).

Answer 4

High;

Positive

Question 5

Good screening tests have (high/low) sensitivity. If not, you get false (positive/negative).

Answer 5

High;

Negative

Question 6

Define incidence. Give example.

Answer 6

Number of individuals DEVELOPING disease over period of time (I.e. New colon cancer cases within the last year)

Question 7

Define prevalence. Give example.

Answer 7

TOTAL number of individuals with disease at particular time (i.e. All individuals with colon cancer in May 2016)

Question 8

Define sensitivity of screen/test.

Answer 8

Proportion of AFFECTED individuals correctly identified by test (true positives)

Question 9

Define specificity of screen/test.

Answer 9

Proportion of UNAFFECTED individuals correctly identified by test (true negatives)

Question 10

Define positive predictive value.

Answer 10

Proportion of patients with positive test results that truly have disease

Question 11

Define negative predictive value.

Answer 11

Proportion of patients with negative test results that truly don’t have disease

Question 12

List some examples of population screening currently used.

Answer 12

1. Pap smear (cervical cancer)

2. Prostate-specific antigen (men over 50; prostate cancer)

Question 13

T/F: NBS (newborn screening) is mandatory in all states for all disorders.

Answer 13

False - mandatory in all states, but only for specifically named disorders

Question 14

Expert Panel originally decided that NBS is required for how many conditions?

Answer 14

29

Question 15

Hearing impairment is discovered in newborn. Which test is performed next?

Answer 15

Direct DNA mutation analysis of connection-26 gene

Question 16

(X)% of all babies have CHD. Heart defect screening is now recommended via (Y).

Answer 16

X = 1
Y = pulse oximetry

Question 17

T/F: Carrier screens typically detect 100% of carriers.

Answer 17

False

Question 18

It’s recommended that CF carrier screening be offered to:

Answer 18

All couples of childbearing age who are Caucasian or Ashkenazi Jew

Question 19

Standard screening includes the most common (X) number of CF mutations out of the (Y) that have been reported.

Answer 19

X = 23
Y = 1900

Question 20

Individuals of certain ethnic group more likely to carry certain (dominant/recessive) conditions due to (X) phenomenon.

Answer 20

Recessive;

Founder mutation

Question 21

(X)% of people worldwide are carriers of a hemoglobinoathy. List some of these diseases.

Answer 21

X= 7

Sickle Cell , beta/alpha thalassemia

Question 22

Routine carrier screening for hemoglobinopathies is done via which methods?

Answer 22

1. Hb Electrophoresis

2. CBC

Question 23

Tay-Sachs is a(n) (X) disease. Children live up to age of (Y).

Answer 23

X = fatal neurodegenerative;
Y = 5

Question 24

Tay-Sachs is especially prevalent in (X) population. Approximately how common is the disease gene mutation in this population?

Answer 24

X = Ashkenazi Jewish

1 in 25 Jews carry the mutation

Question 25

Normal population carries Tay-sachs mutation at what rate?

Answer 25

1 in 300

Question 26

T/F: Screening has brought down the number of Tay-Sachs births in Jewish community below that of non-Jewish community.

Answer 26

True

Question 27

T/F: Mutations for Tay-Sachs among Jews are generaly the same as those found in other populations.

Answer 27

False

Question 28

(X) is more successful than (Y) in screening for Tay-Sachs mutation in non-Jewish populations.

Answer 28

``` X = enzyme screening; Y = genotyping ```

Question 29

It's standard practice to recommend carrier screening for which disease genes to Ashkenazi Jews planning pregnancy?

Answer 29

1. CF 2. Canavan and familial dysautonomia 3. Tay-Sachs

Question 30

There are no published recommendations for carrier screening in (X) population, despite high frequencies for (Y).

Answer 30

``` X = Hispanic Y = Sickle-cell anemia ```

Question 31

List the proposed criteria for Ashkenazi Jewish Screening panel.

Answer 31

1. Serious and well-described 2. Sensitivity over 90% OR carrier frequency greater than 1/100 3. Testing available

Question 32

Jewish beliefs that influence reproduction: Termination of pregnancy (can/can't) be performed if (X).

Answer 32

Can; | X = prior to 40 days

Question 33

Jewish beliefs that influence reproduction: have (few/many) (boys/girls).

Answer 33

Many (fruitful/multiply); at least one boy and one girl

Question 34

T/F: Pre- and Post-natal testing are reproductive options according to Jewish beliefs.

Answer 34

True

Question 35

T/F: Adoption is not a real reproductive option according to Jewish beliefs.

Answer 35

False

Question 36

Women have (X) number of fetal ultrasounds in first trimester. Which two things does the ultrasound measure?

Answer 36

X = 1-2 1. Gestational age 2. Nuchal translucency

Question 37

Increased nuchal translucency, measurement taken via (X) technique, is indicative of:

Answer 37

X = ultrasound; ``` Increased risk for: 1. Aneuploidy 2. Heart defects 3. Skeletal dysplasia 4. Noonan syndrome OR nothing at all... ```

Question 38

Why have certain pan-ethic screens, such as (X), not been incorporated as standard of care?

Answer 38

X = skeletal muscular dystrophy and fragile X syndrome Complex molecular tests and multiple implications of results

Question 39

Aim for maternal serum screening (MSS) is to:

Answer 39

Identify pregnancies with increased risk of open neural tube defect or chromosome abnormality

Question 40

First trimester MSS screening involves measuring serum levels of:

Answer 40

1. PAPP-A (protein) | 2. hCG (gonadotropin)

Question 41

T/F: All women benefit from maternal serum screening.

Answer 41

False

Question 42

Currently, MSS results are reported as (X) if the risk is above a certain cut-off. This is a loaded term.

Answer 42

X = "Screen Positive"

Question 43

MSS results would best be reported using words/phrases like (X).

Answer 43

X = "high risk" or "abnormal"

Question 44

Non-invasive prenatal screening (NIPS) has recently started to involve looking at (maternal/fetal) (X), which is detectable as early as (Y) weeks of pregnancy and has very (short/long) half-life.

Answer 44

Fetal; X = nucleic acid (cell-free DNA) Y = 7 Short

Question 45

What's the major benefit of using non-invasive cfDNA testing?

Answer 45

Offers detection rates for trisomy 21 and 18 without risk of miscarriage (since non-invasive)

Question 46

Limitation: (X) value of non-invasive cfDNA testing is less than ideal.

Answer 46

X = positive predictive

Question 47

T/F: It's safe to say that all patients will benefit from prenatal screening and diagnostic testing.

Answer 47

False

Question 48

Prenatal diagnosis can be performed via which method(s)?

Answer 48

1. CVS (chorionic villus sampling) 2. Amniocentesis 3. PUBS (percutaneous umbilical blood sampling) 4. Fetal biopsy

Question 49

T/F: Prenatal diagnosing, unlike screening, can identify all pregnancies that will have particular condition.

Answer 49

False

Question 50

T/F: CVS and Amniocentesis are nearly 100% accurate methods of prenatal diagnosis.

Answer 50

True

Question 51

Risk of miscarriage is greater in (CVS/amniocentesis).

Answer 51

CVS (1 in 100)

Question 52

(X)% of maternal DNA is fetal in origin. This varies by which characteristics of pregnancy?

Answer 52

X = 10-15 Health, weight, ethnicity

Question 53

T/F: cfDNA has improved accuracy, sensitivity, and specificity over MSS.

Answer 53

True

Question 54

List limitations of cfDNA testing.

Answer 54

1. Only some chromosomes analyzed | 2. 1-5% "no def answer"

Question 55

T/F: cfDNA can detect open neural tube defects.

Answer 55

False

Question 56

Pregnant patient has previous pregnancy with aneuploidy. Which type of prenatal diagnostic test might you suggest?

Answer 56

Cytogenetic (karyotype) analysis

Question 57

Pregnant patient is confirmed carrier of genetic condition. Which type of prenatal diagnostic test might you suggest?

Answer 57

Molecular genetic analysis

Question 58

Which type of prenatal diagnostic test is used to detect open neural tube defects?

Answer 58

Biochemical analysis

Question 59

Based on some studies, about (X)% diagnoses of aneuploidy are terminated.

Answer 59

X = 70-80