29. A genetic testing company offers expanded carrier screening.Amongst the conditions they test for, they provide the followinginformation regarding the carrier frequency and testing sensitivityfor cystic fibrosis (CF) in different populations.
Ethnicity | Carrier frequency | Testing sensitivity |
African American | 1 in 61 | 97% |
Ashkenazi Jewish | 1 in 29 | 93% |
Asian | 1 in 88 | 98% |
Caucasian | 1 in 28 | 92% |
A couple consisting of a Caucasian man and an Asian woman areinterested in doing this expanded carrier screening test.
- Assuming there are no known people affected with CF in eitherof their families, what are the baseline (i.e. before testing)chances of this couple having a child affected with CF?
- The woman does testing first, and she is found to be a CFcarrier. Taking this finding into account, what are the updatedchances of this couple having a child affected with CF?
- The man does testing, and results show he has not been detectedas a carrier. Taking both the man’s and the woman’s testing resultsinto account, what are their updated chances of having a child withCF?
