HD Blog

As a person ages, the coding for 'bad' huntingtin protein starts to get out of whack and make longer and longer strings of glutamine. The longer the string, the more effective the protein is at knocking off the cell. This seems to particularly affect the neural cells in the striatum (due to their structure). The symptoms of HD are due to the loss of these neural cells.

This is why exercise and certain anti-oxidants are believed to slow the progression of the disease - it slows the process of those strings getting longer and longer.

Your base CAG count, and each person actually has two, determines whether you have HD or not. If one of your CAG counts is over 40, than the disease will eventually appear. For those with counts 36-39, it may or may not appear. If it does appear, it tends to be later in life (usually 60's or later). If your count is less than 36 than you will not get the disease. It is possible, but fairly rare, for people with counts of 27-35 to have children who will have a high enough count to get HD.

There is some correlation between the age of onset and the CAG count. But there is quite a bit of variability. The age of onset for those with a count in the low-40's can vary by 20 years. This is because there are other factors that can speed up or slow down the progression of the disease. The PREDICT study is designed to help identify other factors.

In a fairly recent discovery, researchers have found that the presence of one specific gene tends to mean that onset of those with HD will be 5 years sooner. And, no, there is no commercial test available for this gene at the moment.

Science is making very fast progress in understanding the processes that are going on inside the cell. The HD gene was identified in 1993, but I believe the huntingtin protein wasn't identified until 1997. Now it seems every month they make another advance in understanding the interaction and roles of the proteins and enzymes inside the cells. What is learned in Huntington's research is becoming increasingly valuable to those studying other diseases.

Armed with this new knowledge, Scientists are designing treatments that are finding increased success in the lab. Many of which are working their way toward human testing. It is really very exciting to watch as all of this new knowledge unfolds!