APOE-E4 is a gene that is present in about
25% of the U.S. population. Although not everyone who has the gene gets Alzheimer’s,
60% of Alzheimer’s patients have at least one copy of this gene (2). The gene
is thought to have several different roles in the brain and blood. The APOE
proteins are the main transporters of lipids in the brain; however, APOE-E4 is
not as efficient at lipid and A-beta transportation as other variants of this
gene. Therefore, the brain is more vulnerable to acute injuries and the
stresses of aging (1).
In a
recent study researchers from Brown University and Banner Alzheimer’s Institute
have found that infants who carry the APOE-E4 gene tend to have differences in
brain development in comparison to infants without the gene. The researchers used
a specialized MRI technique to image the brain of 162 infants between 2 months
and 25 months, 60 of which had the E4 variant of the APOE gene. In comparing
the MRI images, the researchers found that the children with APOE-E4 gene tend
to have increased brain growth in the frontal lobe and decreased growth in
several parts in the middle and rear of the brain. The areas of decreased
growth are the same areas that tend to be affected by Alzheimer’s disease (2).
It
is important to recognize that these findings do not mean that the infants with this variant are “destined” to develop Alzheimer’s, but that
those who carry the gene APOE-E4 tend to develop differently from a young age.
The researchers postulated that these changes in development may provide a
foothold for the pathology of Alzheimer’s to occur (2).
While
this study does not allow for the early diagnosis of Alzheimer’s or a new ‘miracle’
treatment option, I think the results will be extremely beneficial in the study
of Alzheimer’s disease and how the E4 variant contributes to risk of the
disease later in life.
Sources:
1. Schnabel, Jim. "Why Does APOE-E4 Make Alzheimer's
More Likely?" The Dana Foundation.
N.p., 07 July 2011. Web. 26 Nov. 2013.
<http://www.dana.org/news/features/detail.aspx?id=33588>.
2. Stacey, Kevin. "Brain Imaging Differences in Infants
at Genetic Risk for Alzheimer's." Brain Imaging Differences in Infants at Genetic Risk for
Alzheimer's. EurekAlert, 25
Nov. 2013. Web. 26 Nov. 2013.
<http://www.eurekalert.org/pub_releases/2013-11/bu-bid112213.php>.
I think this is really interesting that they decided to do this. It definitely gives insight to the disease, rather how presence the APOE-E4 gene affects development. I wonder how the parents felt. It would be interesting to see how this would development changes in the long run. I do understand that it is difficult in finding a group of people that are under the same environmental constraints. Perhaps evaluating those in a nunnery or monastery would work just as in the study that Shawna had talked about in class.
ReplyDeleteThis is such an interesting topic! Maybe they can only hypothesize that it has something to do with Alzheimer's because of its correlation between the reduced development in the region that Alzheimer's is also associated with- but they did prove that the gene plays a role in development which is the first step! Now all they need to do is follow these infants in a longitudinal study and maybe they will discover more.
ReplyDeleteThis article is interesting. However, it also leaves many questions. As Jordan said, they need to follow these infants in a longitudinal study and hope for more positive discovery, but longitudinal study has too many variances that are difficult to control and possibly make the research weaker. Furthermore, even if they do find a gene responsible for Alzheimer, they still have a long way to go. I am always amazed by the hard work researchers do to discover new findings. Hope they find one in near future.
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