Human Prion Disease

 

Prion diseases are a group of rare, invariably fatal brain diseases that occur both in humans and animals. They are caused by the presence of an abnormal protein in the brain tissue, called scrapie prion protein (PrPSc), and is believed to result from a change in the shape, of a normal protein which is present in the brain. As the amount of abnormal prion protein grows, it becomes hard to break down, causing brain degeneration and neurologic disease.

Creutzfeldt-Jakob Disease (CJD) is the most common of the human prion diseases. There are three types of CJD. Click over each type for more information.

  1. Sporadic - also called spontaneous, for which the cause it is not known but it is thought to be due to spontaneous misfolding of the normal prion protein.
  2. Genetic - also called genetic or inherited, which is due to a defect in the prion protein gene. 
  3. Acquired - transmitted by infection due to exposure to the infectious prion from contaminated meat, or from transplant of contaminated tissues, or use of contaminated instruments during specific surgical procedures.

The main indications leading to a possible diagnosis of CJD are rapid dementia and one or many of a range of neurological symptoms including unsteady gait, hallucinations, and sudden jerking movements.

CJD reportedly affects approximately one to two persons per million population each year worldwide. In the United States, approximately one in every 6,239 deaths are due to CJD every year, which equates to approximately 400-500 cases per year.

There also exists a form of prion disease, Chronic Wasting Disease (CDW), which affects deer elk, reindeer, sika deer, and moose (e.g., members of the cervid species). For more information, click here.