Introduction to Grid-Computing and Huntington's Disease

         As technology continues to become more advanced and computing power increases exponentially, what once may have seemed to be a complicated task has now become easier and far less complex. A current issue that we face when it comes to analyzing data is that we are unable to build computers fast enough to interpret the data efficiently. However, a solution to this problem has been by the implementation of grid-computing. Grid-computing is rather new technology that uses the power of thousands of personal computers on a network to simultaneously divide and conquer large amounts of data to ultimately achieve a single, common goal. Individual computers are linked on a network using software called middleware, and they each work simultaneously until the work unit is complete. A well-known example that uses grid computing is the organization SETI (Search for Extraterrestrial Intelligence). This organization uses grid-computing to analyze data collected in search for signals from outer space.

        The traditional method for analyzing vast amounts of data would have been to build a super computer. Super computers have long been built and used for projects that require a large amount of computing power. In a quote from Vijay Pande, leader of the Pande Lab at Stanford University, he states how instead of using one computer for 1,000,000 days, you can use 100,000 individual computers for 10 days and complete the same amount of data analysis. Grid-computing allows this high speed information analysis to happen. Grid-computing is beneficial for a number of reasons: (1) it is more cost efficient, (2) it is useful for tasks requiring vast amounts of computing power, and (3) when the computers are networked they can work in concert to achieve a common goal efficiently. In short, the power of grid-computing is infinite.  The ability to analyze large amounts of data quickly is dependent upon the number of volunteers willing to use their personal to computer.

        The purpose of understanding grid-computing is because some of the work currently being done affects all of us. For example, many grid-computing efforts concern the analysis of folding proteins.  Diseases such as Alzheimer’s, Amyotrophic Lateral Sclerosis ALS, and Huntington’s Disease are all because of misfolding of certain proteins. Grid-computing allows researchers to analyze data from the protein folding, which ultimately will allow us to better understand how these specific proteins misfold. Our end goal is that we hope the research being done will lead to cures and/or preventative measures to aid in these diseases. Our group, specifically, is running the grid Folding@Home, which performs analysis on  Huntington's Disease. 

         Huntington's Disease is an autosomal dominant neurodegenerative genetic disorder. It affects between 3 and 7 per 100,000 people of Western European descent. Offspring of an individual with HD have a 50% chance of inheriting the allele causing HD. The genetic defect occurs on chromosome #4 in the gene locus called HTT. What makes Huntington's an increasingly problematic disease is that the onset of symptoms typically does not take place until the person carrying the defective gene is about 35 to 44 years of age. By the time the person knows they have inherited the disease it is very likely that they will have had an opportunity to reproduce.
        What makes the HD gene detrimental is because of how the gene is oriented. The gene includes a series of trinucleotide, CAG, repeats, which ultimately can lead to the over production of the huntingtin protein. For the huntingtin protein a normal allele would include 26 or few CAG repeats. The disease causing alleles would have to include over 36 CAG repeats, and there are two types of HD-causing alleles. Reduced-penetranc HD causing alleles have 36-39 CAG repeats, and full-penetrance HD causing alleles have greater than 40 CAG repeats. Reduced-penetrance means that in some cases the person inheriting the HD allele may or may not be symptomatic.  Full-penetrance means that the individual will be symptomatic.
        Huntington's disease presents with many different symptoms. Some of the most common symptoms are:

• Dystonia
• Involuntary Movements 
• Chorea - twisting and jerking motions
• Dementia
• Aphasia
• Depression
• Lack of Coordination
• Death

        We will soon be interviewing some experts in the field dealing with Huntington's Disease. As we acquire more information about the disease, we will be able to go into more depth about the physiology and genetics of the disease.  We will also talk about current research efforts for treatment and a cure, as well as how the disease is diagnosed clinically.