Genotyping the intro class

2 minute read

Holly Dunsworth, at the University of Rhode Island, is undertaking a unique project with her undergraduate course this semester, providing 23andMe genotyping for every student. She describes some of her thoughts on the “cans of worms” that this may create for her: “First we were snapped, now we’re SNP’d”.

Part of what students have to do this semester is form a 'plan of action.' That's what I've called their assignment where they predict what their SNPs will hold and where they explain what they will do if they find out they're at high risk for a disease or even, yes, that they might not be related to their father. (This discovery doesn't require paternal DNA. Since half of your genome is from your father, and since a few traits are pretty simple, the rare participant with the rare SNP can deduce that they did not get their DNA from their father who doesn't show the trait in question.)

I’ve been discussing this issue a lot with people lately. In a few years, most of my students will have whole-genome genotyping or sequencing done for routine medical purposes, because that’s how cheap it will be. Interpretation of the results will not (necessarily) be cheap, and it may not be appreciably better than it is now.

Some readers will say, “Well, if the interpretation isn’t a lot better than now, nobody will want the results anyway, so it won’t happen.”

I disagree. Take Mendelian disorders. Today, every child in Wisconsin is tested for a few dozen genetic disorders at birth. It is already possible to screen parents for every Mendelian disorder with a frequency of more than one in a thousand. In a short time, that genotyping will be cheaper than the current postnatal testing. Prenatal care already includes a score of tests, and fetal cell genotyping may eventually replace postnatal testing for genetic disorders. Moreover, companies (for example, Counsyl) are already providing genotyping and interpretive services for the couples prenatal testing market. As genotyping becomes cheaper, it will pull in a broader and broader fraction of my students, future college graduates and professionals.

So I’ve taken it as my attitude that my biological anthropology courses must educate them for this future. Our curricula can provide the students useful information about health and ancestry, including both the promise and limits of genetic information. The beauty of the new genetic approaches is that they provide better illustrations of most of the classic topics in human biology and variation. You can see some of that at play in my Principles of Biological Anthropology lectures this semester.