Huntington Disease
Overview
Plain-Language Overview
Huntington Disease is a genetic disorder that affects the brain, specifically the areas controlling movement, thinking, and emotions. It causes progressive problems with coordination, memory, and behavior, leading to difficulties in daily activities. The disease usually begins in mid-adulthood and worsens over time, impacting both physical and mental health. People with this condition may experience involuntary jerking movements called chorea, as well as mood changes like depression. Because it affects the nervous system, it gradually impairs the ability to walk, talk, and think clearly.
Clinical Definition
Huntington Disease is an autosomal dominant neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the HTT gene, leading to abnormal huntingtin protein accumulation and neuronal death. The pathology primarily affects the striatum and cerebral cortex, resulting in progressive motor dysfunction, cognitive decline, and psychiatric symptoms. The hallmark clinical features include chorea, dystonia, executive dysfunction, and behavioral disturbances such as irritability and depression. Disease onset typically occurs between 30 and 50 years of age, with severity correlating to the number of CAG repeats. The condition is fatal, with death usually occurring 15 to 20 years after symptom onset due to complications like pneumonia or injury.