pgEd is always interested to hear new stories about how low-cost genome sequencing is advancing research on the often complex relationship between a person’s genes and his or her health. Over the past few months, we have come across a handful of studies showing a connection between a rare genetic variant (a difference in DNA sequence found in a small percentage of people) and a person’s chance of developing Alzheimer’s disease.
Two groups found that variants in the gene TREM2 are correlated with an increased risk for Alzheimer’s disease (click here and here to read the news coverage). However, mutations are not necessarily a bad thing. In fact, a third report found variants in the APP gene that seem to be protective – reducing a person’s risk for Alzheimer’s (click here to learn more).
Because all of these variants are rare, the majority of people will not be directly impacted by these results. But, these stories demonstrate how genome sequencing is advancing research. They also remind us that a single gene is often not the whole story. The ApoE gene (which we talk about in our lesson on genetics and athletics and the recently added “Overview of Genetics and Sports”) has a common variant called E4 that significantly increases one’s risk for Alzheimer’s. However, it is not a guarantee one way or the other. ApoE is just one piece of a puzzle that includes several genes like TREM2 and APP as well as environmental factors.