PRNP Gene

Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia). The signs and symptoms of prion disease typically begin in adulthood and worsen with time, leading to death within a few months to several years.

Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia). The signs and symptoms of prion disease typically begin in adulthood and worsen with time, leading to death within a few months to several years.

As its name suggests, a Huntington disease-like (HDL) syndrome is a condition that resembles Huntington disease. Researchers have described four HDL syndromes, designated Huntington disease-like 1 (HDL1) through Huntington disease-like 4 (HDL4). These progressive brain disorders are characterized by uncontrolled movements, emotional problems, and loss of thinking ability. HDL syndromes occur in people with the characteristic features of Huntington disease who do not have a mutation in HD, the gene typically associated with that disorder.

HDL1, HDL2, and HDL4 usually appear in early to mid-adulthood, although they can begin earlier in life. The first signs and symptoms of these conditions often include irritability, emotional problems, small involuntary movements, poor coordination, and trouble learning new information or making decisions. Many affected people develop involuntary jerking or twitching movements known as chorea. As the disease progresses, these abnormal movements become more pronounced. Affected individuals may develop problems with walking, speaking, and swallowing. People with these disorders also experience changes in personality and a decline in thinking and reasoning abilities. Individuals with an HDL syndrome can live for a few years to more than a decade after signs and symptoms begin.

HDL3 begins much earlier in life than most of the other HDL syndromes (usually around age 3 or 4). Affected children experience a decline in thinking ability, difficulties with movement and speech, and seizures. Because HDL3 has a somewhat different pattern of signs and symptoms and a different pattern of inheritance, researchers are unsure whether it belongs in the same category as the other HDL syndromes.

Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia). The signs and symptoms of prion disease typically begin in adulthood and worsen with time, leading to death within a few months to several years.

Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia). The signs and symptoms of prion disease typically begin in adulthood and worsen with time, leading to death within a few months to several years.