What are prion diseases?
Prion diseases comprise several conditions. A prion is a type of protein that can trigger normal proteins in the brain to fold abnormally. Prion diseases can affect both humans and animals and are sometimes spread to humans by infected meat products. The most common form of prion disease that affects humans is Creutzfeldt-Jakob disease (CJD).
Prion diseases are rare. About 300 cases are reported each year in the U.S.
Types of prion diseases include:
- CJD. A person can inherit this condition, in which case it's called familial CJD. Sporadic CJD, on the other hand, develops suddenly without any known risk factors. Most cases of CJD are sporadic and tend to strike people around age 60. Acquired CJD is caused by exposure to infected tissue during a medical procedure, such as a cornea transplant. Symptoms of CJD (see below) quickly lead to severe disability and death. In most cases, death occurs within a year.
- Variant CJD. This is an infectious type of the disease that is related to “mad cow disease.” Eating diseased meat may cause the disease in humans. The meat may cause normal human prion protein to develop abnormally. This type of the disease usually affects younger people.
- Variably protease-sensitive prionopathy (VPSPr). This is also extremely rare, it is similar to CJD but the protein is less sensitive to digestion. It is more likely to strike people around age 70 who have a family history of dementia.
- Gerstmann-Sträussler-Scheinker disease (GSS). Extremely rare, but occurs at an earlier age, typically around age 40.
- Kuru. This disease is seen in New Guinea. It's caused by eating human brain tissue contaminated with infectious prions. Because of increased awareness about the disease and how it is transmitted, kuru is now rare.
- Fatal insomnia (FI). Rare hereditary disorder causing difficulty sleeping. There is also a sporadic form of the disease that is not inherited.
Source:
www.hopkinsmedicine.org