Carrier Screening

Question 1

What screening does ACOG recommend for in all people pregnant or planning to become pregnant

Answer 1

SMA, CF, complete blood count

Question 2

What screening does ACOG recommend for specific ethnic groups

Answer 2

Hemoglobinopathies (Africa , Mediterranean, middle eastern, West Indian, or if abnormal CBC)

Question 3

What are CF carrier rates for ashkenazi Jewish ancestry, Caucasian, Hispanic white, African American, Asian American

Answer 3

1/24, 1/25, 1/58, 1/61, 1/94

Question 4

What is the most common cause of SMA

Answer 4

Deletion of exon seven of SMN1

Question 5

What determines the severity of SMA

Answer 5

The number of SMN2 genes

Question 6

What is carrier frequency of SMA

Answer 6

1/40-1/60

Question 7

What mutation causes sickle cell disease

Answer 7

HbSS c.20A>T homozygous

Question 8

What conditions does ACOG recommend testing individuals of ashkenazi Jewish descent for

Answer 8

Canavan disease, cystic fibrosis, familial dysautonomia, tay sachs

Question 9

Who is fragile x screening recommended for

Answer 9

Based on family history, ID suggestive, primary ovarian insufficiency before age 40

Question 10

What are the typical, premutation, & full mutation numbers of repeats for fragile x

Answer 10

Less than 45, 55-200, more than. 200

Question 11

What is the carrier frequency of tay sachs for individuals of ashkenazi Jewish decent

Answer 11

1 in 29

Question 12

What populations have a higher carrier frequency of tay sachs

Answer 12

French Canadian, Cajun descent, Ashkenazi jewish

Question 13

What were some ACMG recommendations regarding carrier screening tests overall

Answer 13

Should just be called carrier screening, a tier system should be utilized, should be ethnic & population neutral & more inclusive of diverse populations, screening can be offered to partners simultaneously

Question 14

What tier/ group of conditions does ACMG recommend screening for in all pregnant people or those planning to become pregnant

Answer 14

Tier 3: conditions with carrier frequency greater than 1 in 200, including x linked conditions

Question 15

When does ACMG recommend consideration of tier 4 carrier screening

Answer 15

Known or possible consanguineous relationship, when warranted by personal or family history

Question 16

What are reasons to move from ethnic based to expanded carrier screening

Answer 16

Patients increasingly have multiple ethnic backgrounds, may not know their ethnic background, may not want to share ethnicity or ancestry, & conditions can still occur outside of high risk populations

Question 17

What should be true about conditions offered on carrier screening per ACOG

Answer 17

Carrier frequency >1 in 100, well defined phenotype, detrimental effect on quality of life, causes physical or cognitive impairment, requires surgical or medical intervention, has early onset, conditions that can be diagnosed prenatally, have delivery managements or interventions that can improve outcomes

Question 18

What are some concerns regarding expanded carrier screening

Answer 18

May be screening for phenotypically mild or variable conditions, too much information can be overwhelming to some patients, no consensus on what conditions should be included