Name:
Date:
"Calendar"
Assignment for Day 15
What does your future hold? A look into gene mapping
Janie &
Maria’s Day!
· Gene testing (Human Genome Project website)
· Pages 53-58 on newborn and adult screening (in Chap. 4, “The Human Genome and Medical Practice”) of your text, How the Genome Works
· You will also read a news article in class
Thinking assignment:
· Background. You have read about different types of genetic testing and purposes for it. As your first article notes, genetic screening involves testing entire populations, not just individuals seeking to satisfy particular personal reasons. The latter might include being tested to diagnose or treat a disease that has already manifested itself, to know their odds of developing certain kinds of breast cancer or degenerative diseases like early-onset Alzheimers, or to determine whether they are a carrier of genes for cystic fibrosis or other particular diseases before deciding to have children. Population screens are quite different in aim and whether voluntary. As currently done at birth for PKU, population screenings are like other public health measures. That is, they involve tests or preventive measures mandated by law or regulation for the health of the general population, as is the case with vaccinations for certain communicable diseases required of children before they may enter public school.
· More background: Both articles talk about the importance of error or uncertainty (imperfect prediction) in test results. The articles described why predictions of illness from genetic tests are often necessarily < 1.0 (sometimes many possible mutations leading to same outcome, etc.).
· Task 1 (for Janie & Maria): Be prepared to discuss both the scientific and ethical pros and cons of genetic testing.
· Task 2 (for remainder of class): Be prepared to discuss how the ethics of genomic testing—and perhaps especially population screening—depends on one sort of scientific limitation: specifically, the degree of error or uncertainty in test results. Pay particular attention to the role of false positives and false negatives, which were discussed in your readings. The following table is meant to clarify the definitions and real-life consequences of these two sorts of error.
|
|
Actually have or will get the disease |
|
|
|
Test results say: |
YES |
NO |
|
|
YES |
True positive |
False positive |
% told “yes, you are affected” |
|
NO |
False negative |
True negative |
% told “no, you are OK” |
|
|
% actually affected |
% actually OK |
100% |