Anthony Khodanian & Sarah Ashley

This is a brain. It deteriorates when you have Huntington's.
This is a brain. It deteriorates when you have Huntington's.


Where on Chromosome is Problem?

All humans have two copies of the Huntingtin gene (HTT) on Chromosome 4, which codes for the protein Huntingtin (Htt), which upregulates the expression of Brain Derived Neurotrophic Factor BDNF. Part of this gene is a repeated section called a trinucleotide repeat (CAG) which varies in length between individuals and may change length between generations. Normally the CAG is repeaded 10-28 times. When the length of this repeated section reaches a certain threshold, 40+ times, it produces an altered form of the protein, called mutant Huntingtin protein (mHtt). The Huntington's disease mutation is genetically dominant: mutation of either of a person's HTT genes causes the disease.



What Is the Problem?


Huntington's Disease is a genetic disorder that causes certain nerves cells in the brain to deteriorate. This deterioration of nerve cells has a large variety of symptoms that can vary from person to person. These symptoms include behavioral changes, abnormal movements, dementia, and more.

Huntington's disease comes in two forms, adult onset and early onset. Adult onset Huntington's disease is more common, and people who have this will begin having symptoms in their 30s and 40s. Early onset Hungtington's Disease accounts for a smaller number of cases and those with this form will start having symptoms when they are a child or an adolescent.

As the disease is passed down, the number of CAG repeats increases, affecting how soon symptoms begin to develop; the more repeats, the sooner it begins showing symptoms. Trinucleotide CAG repeats over 28 are unstable during replication and this instability increases with the number of repeats present. This usually leads to new expansions as generations pass instead of reproducing an exact copy of the trinucleotide repeat.

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What is the Prognosis?


There is no cure for Huntington's disease and prevention treatments are still in research. The disability caused by this disease gets worse over time, and people usually will die fifteen to twenty years after the symptoms begin.

Those with a larger amount of CAG repeats tend to experience more severe symptoms at a younger age, while those with less CAG repeats tend to have slower disease progression. Individuals with more than sixty repeats often develop the disease before age 20.

Most life-threatening complications result from muscle coordination and behavioral changes induced by declining cognitive function. Pneumonia causes deaths in 33% of cases, due to the inability to synchronize movements causing difficulty clearing the lungs. Heart disease causes fatality in 25%. Suicide is the next greatest cause of fatalities, with 7.3% committing suicide and up to 27% attempting to do so.

Worldwide there are 50-100 cases per million. 70 cpm for those of European Descent and 1 cpm for those of African and Asian descent.

So, tell me how you're upset you have Wrinkles
So, tell me how you're upset you have Wrinkles



Cite Your Sources

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001775/
http://en.wikipedia.org/wiki/Huntington's_disease