Matthew Bennett: Study Questions
Diagram of CF inheritance:
Source: http://www.merck.com/pubs/mmanual_home/illus/2i2.htm
Both Matthew and his sister, Kelly were diagnosed with cystic fibrosis. Their pediatrician ordered antibiotic therapy for their respiratory infections. He also prescribed pancreatic enzyme replacement, water-soluble vitamins, and a high-protein, low-fat diet.
Matthew's parents, Richard and Diana, were instructed in chest physiotherapy for both children. The family's day begins with inhalation treatments to loosen the mucus in their children's lungs, followed by a half-hour of postural drainage in which Matthew and Kelly lie across their parents' laps while they pound on their backs to help expel the mucus.
Richard and Diana have always wanted to have four children, but they are concerned about having another child with cystic fibrosis. The Bennetts' physician referred them to a genetic counselor who helped them develop the following pedigree.
Questions:
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- Your name:
- Email address:
- 1. What is the inheritance pattern of cystic fibrosis?
- Autosomal dominant
- Autosomal recessive
- Sex-linked
- 2. Which individuals must be carriers? (Check all that apply.)
- Richard
- Diana
- Kelly
- Matthew
- Mark
- 3. If Richard and Diana decide to have another child, what are the chances that he or she will be phenotypically normal?
- 25%
- 50%
- 75%
- 100%
- 4. What is the chance that Richard and Diana's next child will be a carrier of the CF gene?
- 25%
- 50%
- 75%
- 100%
- 5. The cystic fibrosis gene impedes the function of what type of protein?
- An enzyme.
- A membrane transport protein.
- An intracellular protein.
- A structural protein
- BONUS: Should Richard and Diana have another child? In addition to quality of life issues, your answer should include a discussion of prenatal screening tests.
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