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11.1. Case Study #1

You are the neurology resident in a large academic medical center. Your first patient of the day is Jean Spencer, a 39-year-old woman pregnant with her first child. Jean has been referred to you by her obstetrician, Dr. Ortiz, based on the medical history she and her husband Scott gave. Although Jean's parents died in a car crash when she was just a teenager, she remembers her mother having symptoms that she now knows are related to a neurological disorder. She remembers her stumbling a lot, having violent mood swings, strange arm movements, memory loss, and being aggressive. Her grandparents died when they were young (in their 50s) of heart disease. Jean is also concerned about an uncle (her mother's brother) who died in a mental hospital whom she vaguely remembers hearing had Huntington's disease. Scott says that his father, who is now in his 70s, has similar neurological symptoms (lack of coordination, violent outbursts, etc.) although he has never been to see a neurologist. Dr. Ortiz is considering performing an amniocentesis on Jean, and wants to know if Huntington's disease should be included in the testing.

At 20 weeks gestation, Dr. Ortiz informs the couple that unfortunately, the genetic testing indicated that the fetus carries the gene mutation for Huntington's disease. She refers them back to you to help explain the finding and possible implications.

You explain to the Spencers the implications of the positive test for the fetus. Given what we know about Huntington's disease and its complete penetrance, the baby will surely develop the disease when he or she reaches middle to late adulthood.

Even before the amniocentesis, the couple had decided not to learn the sex of the baby. Now they wonder whether HD is more likely to affect males than females. This might influence them to terminate the pregnancy.

Before you test Scott and Jean for the HD gene, you begin to ask more questions about Scott's parents. Scott reluctantly reveals that his father has a drinking problem, and that he ascribes his father's clumsiness and slurred speech to his alcohol use. Although his father has been drinking for years, Scott shares that these balance and cognition problems are relatively new, as is the aggressive behavior he is showing toward Scott's mother.

After consulting with you and Dr. Ortiz, the Spensers consent to testing themselves to learn which of them has the HD gene so they can better plan for the future. Both Scott and Jean's tests come back negative for the gene mutation.

11.2. Case Study #2

Sylvia Johnson, a 54 year-old woman, has not been herself lately. She has been misplacing objects more frequently, getting lost in familiar places, having trouble remembering simple words, and not remembering things she recently read or saw.

Encouraged by her 25-year-old son Marcus, she has come to see you, a neurologist, for evaluation and perhaps treatment of her decreased memory and increased confusion.

After examining her, you suspect that Mrs. Johnson has early-onset Alzheimer's disease (AD). To confirm your diagnosis, you order blood work for Mrs. Johnson, looking for the genetic mutations that indicate early-onset and familial Alzheimer's disease. Although the rarer form of this disease (accounting for less than 10% of all Alzheimer's patients), Mrs. Johnson's tests indicate that she is indeed suffering from early-onset familial Alzheimer's disease that she likely inherited from one of her parents.

You accept Mrs. Johnson as a patient, and work with her and her son Marcus to mitigate the effects of the disease. You prescribe medications that you hope will slow the brain degeneration, and you help them devise plans for coping as Mrs. Johnson's condition worsens and she requires more help and support. You advise Mrs. Johnson to appoint a health care proxy to make decisions for when she is no longer able to make them herself.

At your teaching hospital, you are running a study on familial Alzheimer's disease, conducting genetic tests on AD patients and their first degree relatives. To participate, patients and their relatives must consent to a blood test for genetic screening.

You approach Marcus to ask him and his mother to participate in your research study. Marcus is hesitant. He sees what the disease is doing to his mother and is afraid of it. If something like that might happen to him, he does not want to know about it in advance. You explain to Marcus that this is not a problem, since the protocol does not permit informing the participants of the results of the genetic tests.

Disclosure of genetic status for research purposes should be considered in consultation with geneticists, counselors, and bioethicists who will consider fully the implications of the disclosure and the relative advantages and disadvantages of learning this knowledge. Informed consent should include a description of the disease, the purpose of the test, assurances that no other tests will be performed on the sample, recommendations and/or referrals to genetic counseling, advice as to the predictive nature and confidence of the tests, and that there are safeguards in place to maintain confidentiality and privacy.

Thus assured, Marcus consents to the study. Mrs. Johnson, on the other hand, becomes upset and irrational, saying that nobody needs her blood but her. Marcus recognizes her reaction as one of the symptoms of her Alzheimer's disease. He calms her down and eventually convinces his mother to sign the form.

A few years later, after his mother's death, Marcus marries, buys a home, and applies for life insurance. He answers the insurance company's questions about his health behaviors and indicators. He discloses his mother's diagnosis of early-onset Alzheimer's disease. The insurance company responds by asking him to undergo genetic testing to determine his risk of developing the condition. Marcus phones you to ask whether the insurance company can demand that he be tested.

Marcus returns to you for help. He asks you about the study you enrolled him in when his mother was first diagnosed, and asks if the insurance company can access those results.

Marcus wants to know your opinion regarding genetic testing. He recognizes the advantages and disadvantages of getting tested and knowing his status, and wants your advice as to what to do.