How DNA repair can go wrong and lead to disease

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Huntington proteins and their nasty 'social network'

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Protein 'filmed' while unfolding at atomic resolution

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Scientists identify protein form linked to Huntington's disease

Scientists at the Gladstone Institutes have discovered how a form of the protein linked to Huntington's disease influences the timing and severity of its symptoms, offering new avenues for treating not only this disease, ...

New drugs target delay of Huntington's symptoms

(Medical Xpress) -- McMaster researchers have discovered a new drug target that may be effective at preventing the onset of Huntington's disease, working much the same way heart medications slow the progression of heart disease ...

New hope in fight against Huntington's disease

Hope for new ways of treating devastating neurodegenerative disorders such as Huntington's disease has been raised by a trans-Atlantic team of researchers thanks to the use of cutting-edge genetic techniques.

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Huntington's disease

Huntington's disease, also known as Huntington's chorea, sometimes abbreviated as HD, is a neurodegenerative genetic disorder that is the most common genetic cause of repetitive abnormal movements called chorea. It was named after American physician George Huntington, who published one of the earliest descriptions of the disorder in 1872. The prevalence of HD varies across the world from one person per million in populations of Asian and African descent, up to seventy people per million in populations of Western European inheritance. Smaller regions within these areas may have a much higher prevalence than the general population. Symptoms can begin at any age, with physical symptoms being noticed first, most commonly this occurs between 35 and 44 years of age. Less commonly, onset is before the age of 20, and the condition, classified as juvenile HD (also known as akinetic-rigid HD or Westphal variant HD), progresses faster with slightly different symptoms. Genetic testing for HD was made possible in 1993 with the discovery of a single causal gene for the disease, the first non-sex-linked dominant disease gene to be found. Consequently, genetic counseling for HD was developed and became a model for other genetically dominant disorders. The genetic test can be performed before the onset of symptoms, at any age—even pre-birth, which has raised various ethical issues and heated debates.

Because it is inherited dominantly, an affected parent has a 50% chance of passing it to each child and the disease runs strongly in families, often affecting several generations. The exact way HD affects an individual varies, even between family members, but its symptoms progress similarly for most individuals. The earliest symptoms are a general lack of coordination and an unsteady gait. As the disease advances uncoordinated, jerky body movements become more apparent, along with a decline in mental abilities and behavioral and psychiatric problems. Physical abilities are gradually impeded until coordinated movement becomes very difficult, and mental abilities generally decline into dementia, often requiring full-time care in the later stages of the disease. Although the disorder itself is not fatal, complications such as pneumonia, heart disease, and physical injury from falls reduce life expectancy to around twenty years after symptoms begin.

The mechanism of the disease is not fully understood, but a number of factors have been identified. A mutation in the Huntingtin gene causes the production of an abnormal form of the protein huntingtin, which in turn produces cellular and anatomical changes in the brain. There is no cure for HD, although there are treatments to relieve some of its symptoms.

Since the late 1960s and the formation of the Hereditary Disease Foundation by Dr. Milton Wexler and the Committee to Combat Huntington's Disease by Marjorie Guthrie, lay organizations have increased in number, playing a key factor in stimulating research, increasing public awareness and providing support for families in many countries. Research directions include determining the exact mechanism of the disease, improvement of animal models to expedite research, clinical trials of pharmaceuticals to treat symptoms or slow the progression of the disease, and studying procedures such as stem cell therapy with the goal of repairing damage caused by the disease.

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