During a work-up for infertility, Brad (32 years old) is found tohave azospermia caused by congenital bilateral absence of the vasdeferens (CBAVD). His physician explains that 75-80% of men withCBAVD have a mutation in both cystic fibrosis transmembraneconductance regulator (CFTR) genes. The physician recommends thatBrad have CFTR genetic testing. Brad (a pediatric nurse) questionshis physician's medical acumen, exclaiming that he has absolutelyno pulmonary or pancreatic symptoms common with cystic fibrosis nordoes he have any family history of the disease. The physicianexplains that although mutations in CFTR are most often associatedwith pulmonary disease and pancreatic insufficiency, some men withtwo mutations have no symptoms other than CBAVD. Brad is laterdiagnosed with cystic fibrosis when he is found to carry an IVS8-5Tmutation in one CFTR gene and a P499A mutation in the other CFTRgene.
1. Do you agree with the "diagnosis" of cystic fibrosis? Explainyour answer.
2. What impact might this diagnosis have on his ability to obtainlife, health, &/or disability insurance?
3. Explain how it is possible that Brad has two mutated CFTR geneswhen no one else in his family has cystic fibrosis.
4. Brad's CFTR genes, altered by mutations are called: (choose thebest answer)
a) Polymorphisms
b) Alleles
c) Markers
d) Autosomes
5. Because Brad carries two different CFTR mutations, it would beappropriate to say he is:
(Choose the best answer and explain your choice.)
a) Homozygous for the CFTR mutations
b) Hemizygous for the CFTR mutations
c) Heterozygous carrier for the CFTR mutations
d) Compound heterozygous for the CFTR mutations
6. The CBAVD is referred to as the (genotype / phenotype) and theIVS8-5T / P499A mutations as the (genotype / phenotype).
With the technique, microscopic epididymal sperm aspiration (MESA),Brad may be able to produce biological children. Assuming thatBrad's wife is not a carrier of a CFTR mutation:
7. What is their risk for having a child with cysticfibrosis?
8. What are their chances for having a child that is a carrier ofone of Brad's CFTR mutations?
9. If Brad's wife is found to be a carrier of one of the 1000possible CFTR mutations, what is their chance of having a childwith cystic fibrosis?
During a work-up for infertility, Brad (32 years old) is found tohave azospermia caused by congenital bilateral absence of the vasdeferens (CBAVD). His physician explains that 75-80% of men withCBAVD have a mutation in both cystic fibrosis transmembraneconductance regulator (CFTR) genes. The physician recommends thatBrad have CFTR genetic testing. Brad (a pediatric nurse) questionshis physician's medical acumen, exclaiming that he has absolutelyno pulmonary or pancreatic symptoms common with cystic fibrosis nordoes he have any family history of the disease. The physicianexplains that although mutations in CFTR are most often associatedwith pulmonary disease and pancreatic insufficiency, some men withtwo mutations have no symptoms other than CBAVD. Brad is laterdiagnosed with cystic fibrosis when he is found to carry an IVS8-5Tmutation in one CFTR gene and a P499A mutation in the other CFTRgene.
1. Do you agree with the "diagnosis" of cystic fibrosis? Explainyour answer.
2. What impact might this diagnosis have on his ability to obtainlife, health, &/or disability insurance?
3. Explain how it is possible that Brad has two mutated CFTR geneswhen no one else in his family has cystic fibrosis.
4. Brad's CFTR genes, altered by mutations are called: (choose thebest answer)
a) Polymorphisms
b) Alleles
c) Markers
d) Autosomes
5. Because Brad carries two different CFTR mutations, it would beappropriate to say he is:
(Choose the best answer and explain your choice.)
a) Homozygous for the CFTR mutations
b) Hemizygous for the CFTR mutations
c) Heterozygous carrier for the CFTR mutations
d) Compound heterozygous for the CFTR mutations
6. The CBAVD is referred to as the (genotype / phenotype) and theIVS8-5T / P499A mutations as the (genotype / phenotype).
With the technique, microscopic epididymal sperm aspiration (MESA),Brad may be able to produce biological children. Assuming thatBrad's wife is not a carrier of a CFTR mutation:
7. What is their risk for having a child with cysticfibrosis?
8. What are their chances for having a child that is a carrier ofone of Brad's CFTR mutations?
9. If Brad's wife is found to be a carrier of one of the 1000possible CFTR mutations, what is their chance of having a childwith cystic fibrosis?
