Exploring Bioethics - NIH Office of Science Education - National ...

Part II: Instructions1. With a partner, read the information below. One person should read the question aloud, andthe other should read the answer aloud.2. Underline the facts that might influence your decision of whether or not to open your envelope.Copyright © 2009 Education Development Center, Inc. Exploring Bioethics.Permission granted for classroom use.Scientific QuestionWhat is Alzheimer’s disease?What different kinds ofAlzheimer’s exist?What causes Alzheimer’s?What gene is tested?If you have E4, how likely areyou to get Alzheimer’s?Is it possible to have E4 butnever get Alzheimer’s?Is it possible to not have E4but still get Alzheimer’s?Can you have surgery ortake any medicationto prevent yourself fromgetting Alzheimer’s?AnswerAlzheimer’s disease kills brain cells and causes problems with memory, thoughtprocesses, and behavior. Eventually, the disease is fatal. People usually haveAlzheimer’s disease for 5 to 20 years before dying of it.Different types of Alzheimer’s disease arise at different times in a person’s life.This genetic test gives information regarding the most common type ofAlzheimer’s (generally referred to simply as Alzheimer’s disease), which arisesafter age 65. However, there is also early-onset Alzheimer’s disease, which arisesin a person’s 30s, 40s, or 50s. Early-onset Alzheimer’s disease is quite rare.For any one person, Alzheimer’s disease does not have a single cause. Instead,there are many risk factors; some of these may be inherited, while others maybe environmentally influenced. Some studies, for example, show that type 2diabetes, unhealthy arteries, and severe head injuries could contribute to overalllifetime risk of Alzheimer’s disease.The gene is for a protein called apolipoprotein E, or APOE (pronounced ap-ohee).You inherit one copy of the gene from each biological parent. The APOEgene comes in three varieties (alleles): E2, E3, and E4. Recent research showsthat the E4 version contributes most to Alzheimer’s risk.Your chance of getting Alzheimer’s if you have one E4 allele depends on what yourother allele is. If you have two E4 alleles, your chance is 15 times greater thansomeone who inherited E3 from both parents (baseline). If your other allele is E3,your chance is 3 to 5 times greater, and if your other allele is E2, your chance is thesame as a person with two E3 alleles (baseline).Yes. People who have E4 generally have a 13–57% lifetime chance of developingAlzheimer’s. Clearly, this risk is nowhere close to 100%.Yes. There are many other risk factors that influence a person’s lifetime chanceof getting Alzheimer’s disease. More than 30% of people with Alzheimer’sdisease do not have E4.No. You currently cannot prevent Alzheimer’s disease.Master 4.2 (Page 2 of 3)