Scenario #3 - Mr. and Mrs. C
These scenarios are based on actual case studies or current events., provided by UC Berkeley Program in Genetic Counseling and Georgetown University Medical Center. Feel free to post your comments and compare your viewpoint with other on-line visitors. All (reasonable) comments below are posted to the ETHEX listserv.
Mr. and Mrs. C come to a genetics clinic for prenatal diagnosis.
They have each been tested to determine whether they carry the gene for cystic fibrosis, a hereditary lung disease that causes severe breathing problems.
The cystic fibrosis gene is recessive, so a child must inherit a copy from each parent to get the disease. In this case, both Mr. and Mrs. C are carriers for the cystic fibrosis gene. The specific mutations for each parent were identified in earlier tests.
Mrs. C, who is pregnant, undergoes prenatal diagnosis to determine if the fetus is affected. DNA analysis indicates that the fetus does have two copies of the cystic fibrosis gene, but one of the mutations it carries is different from that of either Mr. or Mrs. C. That makes it virtually certain that Mr. C is not the baby's father.
Should the genetics counselor tell both Mr. and Mrs. C about the test results?
Should Mr. C be told that he is not the father?
The baby's biological father is also a carrier. Should the genetics counselor attempt to identify him and inform him that there is a risk that his future children may inherit cystic fibrosis?
This case study, provided by the U.C. Berkeley Program in Genetic Counseling and Georgetown University Medical Center, is based on a real situation.
The Exploratorium, 3601 Lyon Street, San Francisco, CA 94123