Huntington’s disease (HD) is a progressive, fatal, neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin gene, which encodes an abnormally long polyglutamine repeat in the huntingtin protein (Ross et al. 2011). The signs and symptoms of Huntington's disease (HD) consist of motor, cognitive and psychiatric disturbances. Other less well-known, but prevalent and often debilitating features of HD include unintended weight loss, sleep- and circadian rhythm disturbances and autonomic nervous system dysfunction. The mean age at onset is between 30 and 50 years, with a range of 2 to 85 years. The mean duration of the disease is 17-20 years. The progression of the disease leads to more dependency in daily life and finally death (Roos, 2010). HD has served as a helpful model in studying other, more common neurodegenerative diseases such as Parkinson's disease and Alzheimer's.
References Ross, Christopher A, Tabrizi, Sarah J., Huntington’s Disease: from Molecular Pathogenesis to Clinical Treatment. 2011. Roos, R.A. Huntington's disease: a clinical review. Orphanet J Rare Dis5, 40 (2010). https://doi.org/10.1186/1750-1172-5-40