Case Introduction

Huntington’s disease (HD) is an extremely rare, autosomal dominant disorder. It is a neurodegenerative condition, meaning that neuronal function is lost and neural cells die over time. Symptoms include chorea (jerky, uncontrolled movements), dementia, and depression. The condition is particularly devastating in that, while one can know one’s fate quite early in life (through a genetic test), currently there is no cure.

Your Task

Prior to discussing this case in class, your task is to read one or more of the assigned resources listed at the end of this section and use that in combination with information in your textbook and notes to formulate answers to the focus questions listed below. You may also need to search for additional articles using such databases as PubMed, a searchable on-line database of articles from medical journals maintained by the National Library of Medicine (see Resources below for the web address). This information will help prepare you to address the scenario presented in the case study.

Focus Questions

• What are the causes of HD?
• What are the symptoms of HD, and how do they compare to other neurodegenerative diseases? (see Bossy-Wetzel et al. 2004)
• How does the disease progress (i.e., what happens as it gets worse) and how is it treated? (see Nance, 2007, and Shoulson and Fahn, 1979)
• What are striatal neurons and what is their role? How are gamma amino-butyric acid (GABA) levels related to striatal neurons? (see Picconi et al., 2006; Smith, Brundin and Li, 2005)
• What are the roles of the mitochondrial membrane potential and intracellular calcium levels in neuron function and in cell death? (see Cattaneo and Calabresi, 2002; Panov et al., 2002)

Resources

Basic Information

National Institute of Neurological Disorders and Stroke

http://www.ninds.nih.gov/disorders/huntington/huntington.htm Last accessed: November 4, 2008

Huntington’s Disease, On-line Index of Mendelian Inheritance in Man

http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=143100 Last accessed: November 4, 2008

Huntington’s Disease Society of America

http://www.hdsa.org/ Last accessed: November 4, 3008

Huntington’s Outreach Project for Education at Stanford

http://www.stanford.edu/group/hopes Last accessed: November 4, 3008

Resources for Further Searches of the Scientific Literature

PubMed

http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed

See also specific databases available through institutional library websites (for example, Proquest, JSTOR, Web of Science, Biological Abstracts, etc.)

Resources for Researching Focus Topics

Genetics and Protein Dynamics

Bossy-Wetzel, E., et al. 2004. Molecular pathways to neurodegeneration. Nature Medicine 10: S2–S9.

Neurobiology

Picconi, B., et al. 2006. Plastic and behavioral abnormalities in experimental Huntington’s disease: A crucial role for cholinergic interneurons. Neurobiology of Disease 22(1):143–152.

Membrane Potential and Calcium Levels

Panov, A.V., et al. 2002. Early mitochondrial calcium defects in Huntington’s disease are a direct effect of polyglutamines. Nature Neuroscience 5(8):731–736.

Mitochondrial Function

Cattaneo, E., and P. Calabresi. 2002. Mutant huntingtin goes straight to the heart. Nature Neuroscience 5(8):711–712.

Patient Care

Nance, M.A. 2007. Comprehensive care in Huntington’s disease: A physician’s perspective. Brain Research Bulletin 72(2–3):175–178.

Shoulson, I., and F. Fahn. 1979. Huntington disease: Clinical care and evaluation. Neurology 29(1):1–3.

Research Techniques

Smith, R., P. Brundin, and J.Y. Li. 2005. Synaptic dysfunction in Huntington’s disease: A new perspective. Cellular and Molecular Life Sciences 62(17):1901–1912. [See especially animal model section.]

Supplemental Resources

YouTube

http://www.youtube.com/

Several videos are available that show the movement phenotype.

Date Posted: January 20, 2009.

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