Wednesday, August 27, 2014

Down Syndrome Provides Insight into Alzheimer's

It has been known for years that individuals who have Down Syndrome have a higher rate of Alzheimer's, particularly early on-set Alzheimer's than the rest of the population.  Down Syndrome is also called Trisomy 21 because the disorder is caused by three copies of the 21st chromosome.  It appears that one of the genes on the 21st chromosome is involved in the production of Beta amyloid, an amino acid which has been implicated in the production of amyloid plaques in the brain.

In all the reading I have done since Lyn's diagnosis, I read time and again that the rate of Alzheimer's is particularly high.  However, what I did not previously pick up on is that by the age of 40 all individuals with Down Syndrome have the pathology of Alzheimer's.  This means that they have the amyloid plaques in their brains even if they are not yet demonstrating clear cognitive or memory issues.  Perhaps we have previously missed this because so many die very young as a result of cardiac issues and, until now, they really have not been the focus of concerted or widely available research.  What research has been done has been mostly focused on how to improve their cognitive abilities or reverse other effects of the syndrome.  This may be changing.

Scientists have enlisted the help of individuals with Down Syndrome in a study to see if a new drug may be used as a preventative therapy.  One of the issues with testing such a drug has been identifying someone who may develop Alzheimer's years in the future when there is no obvious indicator for them to have it now when such a therapy may be most effective.  Could I develop Alzheimer's in 10, 20 or even 40 years.  Sure.  Would I be a good candidate for a long-term study into a preventative drug?  Not without significant testing to see if I'm already at risk though I'm not showing symptoms.  An individual with Down Syndrome, however, is a great candidate because they are essentially guaranteed to get Alzheimer's if they live long enough.  We see Alzheimer's in a couple of people my sister has known through Special Olympics and, like her, they are only in their 40s or 50s.

Brilliant!

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