Preliminary Analysis of Huntington's Disease in South Korea

Background: There have been epidemiological studies of Huntington’s disease (HD) in various populations and nations. Only a few studies describing clinical characteristics have been reported in Asia. Objective: To conduct preliminary analyses of demographic, clinical and genetic characteristics of HD in South Korea. Methods: From 1994 to 2011, thirty six subjects were diagnosed as HD in Seoul National University Hospital. Demographic, clinical and genetic data were carefully analyzed in all subjects. Results: Mean age of onset was 46.5± 12.7 years and mean expanded CAG repeat size was 45.4± 4.7. Twenty-eight subjects (80%) had a family history of HD. Chorea was the most frequent symptom at first visit (89%). Proportion of cognitive decline (36%) and psychiatric symptom (28%) at first visit were lower than proportion of previous reports. A negative correlation (Pearson correlation coefficient−0.757, p= 0.001) was found between expanded CAG repeat size and age of onset. Seven subjects without family history of HD had higher mean age of onset (54.0± 8.1) and smaller expanded CAG repeat size (42.4± 2.7). Cognitive problems at first visit of subjects without family history were more prominent than those with family history (86% vs. 25%). Conclusions: This study is the first demographic, clinical and genetic analyses in South Korea. These results will be helpful to stimulate more large-scale research in South Korea and other Asian nations.