following the onset of visible symptoms. Juvenile Huntington's disease has a life expectancy rate of 10 years after onset of visible systems. Most life-threatening complications result from muscle coordination, and to a lesser extent, behavioral changes induced by declining cognitive function. The largest risk is pneumonia, which causes death in one third of those with HD. As the ability to synchronize movements deteriorates, difficulty clearing the lungs, and an increased risk of aspirating food or drink both increase the risk of contracting pneumonia. The second-greatest risk is heart disease, which causes almost a quarter of fatalities of those with HD. Suicide is the third greatest cause of fatalities, with 7.3% of those with HD taking their own lives and up to 27% attempting to do so. To what extent suicidal thoughts are influenced by behavioral symptoms is unclear, as they signify a desire to avoid the later stages of the disease. Suicide is the greatest risk of this disease before the diagnosis is made and in the middle stages of development throughout the disease. Other associated risks include choking; due to the inability to swallow, physical injury from falls, and malnutrition. Epidemiology The late onset of Huntington's disease means it does not usually affect reproduction. The worldwide prevalence of HD is 5–10 cases per 100,000 persons, but varies greatly geographically as a result of ethnicity, local migration and past immigration patterns. Prevalence is similar for men and women. The rate of occurrence is highest in peoples of Western European descent, averaging around seven per 100,000 people, and is lower in the rest of the world; e.g., one per million people of Asian and African descent. A 2013 epidemiological study of the prevalence of Huntington's disease in the UK between 1990 and 2010 found that the average prevalence for the UK was 12.3 per 100,000. Additionally, some localized areas have a much higher prevalence than their regional average. One of the highest incidences is in the isolated populations of the Lake Maracaibo region of Venezuela, where HD affects up to 700 per 100,000 persons. Other areas of high localization have been found in Tasmania and specific regions of Scotland, Wales and Sweden. Increased prevalence in some cases occurs due to a local founder effect, a historical migration of carriers into an area of geographic isolation. Some of these carriers have been traced back hundreds of years using genealogical studies. Genetic haplotypes