Hello all –
Thanks for an engaged session yesterday. It was great to have so
many of you on, and we appreciated the robust conversation in the chat box.
I wanted to follow up with logistical issues about next week and one clarification about the content from yesterday.
Logistically, I wanted to mention again that by the end of this
week you will all be assigned to a group within the forum. You will use that
group for posting your homework by 8:45 on the day of class. The homework for next week should be posted shortly. Let me know if you
have any questions about that. Thanks. In addition to the reading for next week, there will also be a 30 minute pre-session video you should watch that presents some of the core concepts for next week's session - please watch it before you come on Tuesday so you can be prepared to get the most out of the time with Dr. Shariff-Marco and Dr. Gomez!
In terms of the content that was
presented today, I wanted to briefly revisit the content regarding Ancestry
Informative Markers (AIMs) and the relationship of these markers to race and
the social definition of race. As Dr. Bibbins-Domingo showed in her slides,
there is a correlation between AIMs (which are markers of genetic variation) and self-identified race. But, for several reasons, having this correlation does not indicate that race is biological/genetic for several
reasons. First, this is an imperfect correlation, with, for example, people
identifying as Black having a range of proportions of African ancestry (slide
57). The relationship between racial category and AIMs will vary by context and
history, as this social context determines how race is defined. Second, the finding of
specific markers being stratified across ancestry groups does not mean that
ancestry is a marker of substantial genetic variation – rather it only means
that we can find specific markers, but not that these markers creates
genetically distinct categories. This is particularly true as AIMs do not necessarily
code for anything informative or themselves have an effect on outcomes. This
variation in ancestry does, however, have the potential to help us with discovery
science – e.g. we can leverage this variation to understand factors that can
contribute to disease (one example of this in kidney disease will be discussed
in Week 4). In addition, specific polymorphisms that are associated with
ancestry may be useful to target therapies (e.g. in asthma). However, the ideal
would not be to use ancestry to determine likelihood of having a specific
polymorphism, but rather to measure the polymorphism itself. In other words,
using ancestry as a way to stratify populations with respect to genetic risk is
better than using the social category of race, but still does not get at individual
level differences that we really care about.
This content is challenging and I welcome questions or
comments to clarify it on the forum. Thanks so much!
