Juvenile Huntington disease
Type of disease: Rare conditions
Juvenile Huntington disease (HD) is a less common, early-onset form of Huntington disease that begins in childhood or adolescence. It is also a progressive disorder that causes the breakdown of brain cells in certain areas of the brain. This results in uncontrolled movements, loss of intellectual abilities, and emotional disturbances. Juvenile HD is defined by the onset of symptoms before age 20 years and accounts for 5-10% of HD cases. It is inherited in an autosomal dominant pattern and is caused by a large number of CAG trinucleotide repeats in the HTT gene. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. Most often, children with juvenile HD inherit the expanded CAG trinucleotide repeat from their fathers, although on occasion they inherit it from their mothers. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.