Prion diseases are a group of rare conditions which affect both humans and animals. These diseases cause fatal damage to the brain.
There are three distinct causes of the human diseases:

  1. 1) They can develop spontaneously for unknown reasons. This is called sporadic CJD (sCJD) and is the most common form of human prion disease.
  2. 2) They can be inherited as a result of a faulty gene. This is known as inherited prion disease or familial CJD.
  3. 3) They can be acquired as a result of exposure to prions in the environment. For example, variant CJD (vCJD) is acquired by eating food contaminated with BSE, a prion disease in cattle.

Sporadic CJD is caused when healthy proteins, which exist normally in the human body, spontaneously become misshapen and form chains that build up in the brain.

These chains of misshapen proteins, which are called prions, stick to other healthy prion proteins causing them to become misshapen too.

This process repeats itself and the disease spreads through the brain.

This build-up of abnormal prion proteins causes brain cells to die affecting memory, thinking, talking, balance, movement and behaviour and eventually leads to the death of the patient.

There is no treatment or cure for CJD. At present, caring for patients with CJD involves trying to keep the person as comfortable as possible and using medicines to reduce symptoms.

While a few patients may live for a year or more, most sadly die within four to six months of symptoms starting and on average within six weeks of being diagnosed.

Approximately 120 new cases of sporadic CJD are diagnosed in the UK each year.

Around one in every 5,000 deaths in the UK is due to CJD.

Sporadic CJD occurs at the same level in all countries so this equates to approximately 10,000 new cases a year worldwide.

Stakeholder organisations

The Medical Research Council (MRC) Prion Unit at UCL (University College London) is a national centre of excellence for research into prion disease.

It was established in 1998 at the request of the Government to tackle public health problems caused by prions and to develop treatments.

The Unit is core funded by the MRC but integrated within UCL.

The National Prion Clinic (NPC) is the NHS national referral centre for prion disease. It is part of University College London Hospitals NHS Foundation Trust (UCLH).

The NPC is funded by the NHS to provide diagnosis and care for patients with, or suspected to have, any form of human prion disease.

Around 120 patients a year with sporadic CJD are referred to the NPC. The NPC also cares for most families with inherited prion disease and acquired prion diseases.

The clinic works in partnership with the MRC Prion Unit at UCL.

Further information

Please contact the National Prion Clinic (NPC) team on 020 7679 5142 or email

The treatment has only been available to UK residents registered with a UK general practitioner (GP) who are entitled to National Health Service (NHS) care and who meet strict clinical criteria.

We have reached the end of our supply of PRN100 and will not be treating further patients with the drug at this time.

The Cure CJD Campaign has produced the following useful video explaining prion disease and the PRN100 treatment: