Brianna's paper

Searching for A Cure: The Genetic Investigations of Alzheimer’s Disease
Brianna Carter

Alzheimer’s disease (AD) affects at least 5 million people aged 30 and up in the United States and is now the sixth leading cause of death. AD is a serious brain disorder that was discovered in 1906 by Alois Alzheimer, a German physician. AD is usually diagnosed when it is already in its advanced stages, sometimes as many as 20 years after the disease has first begun to take over the brain. As the disease progresses, things called plaque and tangles move through the brain, eventually killing the cells. When beta-amyloid (Aβ) proteins stick together, plaque is formed, blocking synapses signaling. Tangles are formed when the tau protein that keeps the transport pathway organized collapses, causing the pathway to become tangled, preventing essential nutrients from getting to the brain cells. As the cells begin to die, the brain begins to shrink, as in figure 1, and a person begins to experience memory loss and trouble thinking and speaking. In the most advanced stage, the patient gets lost and forgets how to take care of themselves1.
Why does the tau protein collapse and why does the Aβ stick together? Cao et. Al., states that the accumulation of Aβ is the beginning of the AD pathway so most research has been focused on finding a way to reduce the amount of the Aβ in the brain but some more recent tests have shown that reducing the effects of the increased amount of Aβ can improve some behavioral changes caused by AD. There are some mutations that increase the Aβ expression but there are also some that decrease the expression of Aβ. Studies have also shown that mutations in the tau gene cause the dementia associated with AD4.

Works Cited
1. Alzheimer’s Association. “Alzheimer’s Facts and Figures.” Alzheimer’s Association. 13 June 2008. Alzheimer’s Association. 12 Mar. 2009 <>.
2. Cao, Weinhaun, et al. “Identification of Novel Genes That Modify Phenotypes Induced by Alzheimer’s &#946;-Amyloid Overexpression in Drosophila.” Genetics 178 (Mar. 2008): 1457-1471.
3. Selkoe, Dennis J. “Amyloid Beta-Protein and the Genetics of Alzheimer’s Disease.” The Journal of Biological Chemistry 271.31 (1996): 18295-18298.
4. Shulman, Joshua M, and Mel B Feany. “Genetic Modifiers of Tauopathy in Drosophila.” Genetics 165 (Nov. 2003): 1233-1242.
5. Tanzi, Rudolph E, and Lars Bertram. “New Frontiers in Alzheimer’s Disease Genetics .” Neuron 32.2 (2001): 181-184.

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