It just so happens that I talked about this distinction in my Lifespan
Development course yesterday. I show a really wonderful PBS special on
genetic testing (I believe it was called "A Question of Risk"), in which
various persons are faced with test results indicating high risks of heart
disease and Alzheimer's. I think that the special made it fairly clear how
predisposition and actually getting a disease are two different things, but
I continued by talking about a hypothetical gene causing a predisposition to
skin cancer. Students don't seem to have any trouble understanding that in
such a case, despite a predisposition, actually contracting cancer could be
headed off by avoiding too much sunlight.
The same video begins with a pregnant woman who discovers that she carries
a gene for Cystic Fibrosis, then discovers that her husband does as well,
then discovers (through prenatal testing) that both of her twins have CF
(it's a real heartbreak, and you could hear a pin drop in class...). In that
instance, of course, the twins do not have a predisposition for CF - they
actually HAVE CF.
Paul Smith
Alverno College
Milwaukee
> I was listening to a program on NPR about DNA this morning when they
> made a point that genetics pre-disposes people to get cancer or not
> get cancer, etc. It occurred to me that my students do not have a
> very good understanding of the difference. And it made me think
> about how to get them to understand the distinction so that when they
> hear news reports they will apply that knowledge. So my question
> is how do you handle this issue in your courses?
>
> Joyce Morris
> Public Health Sciences
> Wichita State University
>
