Creutzfeldt-Jakob disease (CJD) is a rare, fatal, degenerative brain disorder characterized by rapidly progressive dementia.

CJD can be categorized into different subtypes:

  • Sporadic CJD—most common type; usually affects people aged 50 years and older
  • Familial CJD—an inherited form of the disease
  • Iatrogenic CJD—contracted through medical procedures, such as injections of growth hormone, or receipt of corneal transplants or dura mater implants from affected donors

Variant CJD (vCJD) is a different prion disease caused by eating contaminated beef products. This variant form differs from other forms of CJD because it affects younger people and has a longer average time course.

It is generally believed that CJD is caused by infectious proteins called prions. Prions are normal proteins in the body. If these prions fold up in a different way than normal, they may transform into the protein that causes the illness. The build-up of abnormal prions may be linked to the brain damage associated with CJD.