Topic > The role of polyglutamine expansions in Huntington's disease...

'Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder characterized by personality changes, motor impairment, and subcortical dementia. It is associated with selective neuronal cell death that occurs primarily in the cortex and striatum.' (Scherzinger et al, 1997). HD causes emotional problems, uncontrolled movements and loss of the ability to think. It can lead to disability and death due to the disease. There are two forms of this disease: adult onset and early (juvenile) onset. Adult onset is by far the most common for HD; symptoms develop in the mid 30s/40s, an individual will live on average 20 years after symptoms and signs begin. Premature signs and symptoms are depression, involuntary movements, difficulty learning new information, poor coordination and balance; all of this can progress very seriously. When HD develops into spasms or jerks, it is called chorea. HD can be referred to Huntington's chorea. “HD usually begins in middle age, but a juvenile form, defined by the onset of symptoms before age 21, is present in approximately 7% of HD cases.” (Nance, 2001) It presents similar symptoms, however the disease progresses more rapidly than the form that begins in adulthood. Gente's (1985) findings showed findings by others that most young-onset patients inherit the gene from their fathers and that the late-onset form is more frequently inherited from affected mothers. The disorder is caused by CAG/polyglutamine (poly Q) repeat expansions in the first exon of a gene that encodes a large protein of approximately 350 kDa with unknown function.' (Scherzinger et al, 1997) Zhang et al state that, due to the expansion of polyQ repeats within the protein, it causes neurodegenerative diseases. The expansion of CAG repeats encodes f...... middle of paper ......, C. and Bates, G, P. (2004). Huntingtin and molecular pathogenesis of Huntington's disease. EMBO reports 5. 958-963Nance, M, A. and Myers, R, H. (2001)Panov, A, V., Gutekunst, C., Leavitt, B, R., Hayden, M, R., Burke, J, R., Strittmatter, W, J. And Greenamyre, J, T. (2002) Early mitochondrial calcium defects in Huntington's disease are a direct effect of polyglutamines. Natural neuroscience. Volume 5 no. 8Ross, C, A. (2002). Polyglutamine pathogenesis: emergence of a unifying mechanism for Huntington's disease and related disorders. Neuron, vol. 35,819-822.Scherzinger, E., Lurz, R., Turmaine, M., Mangiarini, L., Hollenbach, Birgit., Hasenbank, R., Bates, G, P., Davies, S, W., Lehrach, H and Wanker, E, E. (1997). Huntington-encoded polyglutamine expansions form amyloid-like protein aggregates in vitro and in vivo. Cell, Vol.90, 549-558.Zhang,