Author: Yana Nencheva, Biochemist, PhD candidate in Biophysics

What is mad cow, spongiform encephalitis

Knowing how important proteins are for us, we must be aware that they are not only good, it turns out that there are also "bad" ones. Here I am talking about mutated prions [ref. 1]. These are infectious particles that consist only of protein [ref. 2]. Stanley Prusiner, a professor of neurology and biochemistry, won the Nobel Prize in Physiology or Medicine in 1997 when he discovered them.

Collectively, prion disorders affect about 1 in 1,000,000 people a year. It is estimated that genetic prion diseases make up only about 15% of all individuals with prion diseases. Because rare diseases often remain undiagnosed or misdiagnosed, it is difficult to determine their true incidence in the general population.

For example, a disease known as fatal familial insomnia (FFI) affects both men and women equally often. The average age at which the first symptoms appear is 45-50 years, although the described disorder occurs in individuals in their teens and up to their 70s. Fatal familial insomnia has been described in populations worldwide.


Prion - protein went the bad way

Prions are made up of about 250 amino acids and the protein from which they are made has a name - PrP, which is easier to remember on behalf of Ilon Musk'schild.

When examining the infectious causative agent of certain diseases, scientists found that it is a prion with a falsely pleated protein (folding is also called conformation).

If it doesn't sound scary to you, then keep in mind that the mutated prion has one goal -to turn the nemutated prions around it into mutantones.

So far, it is not entirely clear why good pion goes down a bad path.

    • Mad cow (Bovine Spongiform Encephalopathy, SEG) or Creutzfeldt-Jakob disease
    • Kuru or The Laughing Death
    • Fatal family insomnia

What is mad cow and Creutzfeldt-Jakob disease

Prions, mad cow, spongiform encephalitis

The disease was first diagnosed in 1985in the UK and has been calledbovine Spongiform Encephalopathy(BSE) or "mad cow" [ref. 5].

There are several ways of infecting a mad cow:

  • When consuming meat from a sick animal - the prions fall into the digestive tract, then into the blood and somehow overcome the blood-brain barrier.
  • When blood transfusions from a ailing individual;
  • With improperly cleaned tools during surgery, if the previous patient suffered from the disease.

Mad cow is a form of Creutzfeldt-Jakob disease. These diseases are incurable and deadly.

What is Kuru or "laughing death"

One of the purely practical reasons not to resort to cannibalism is Kurudisease.

Besides the common for transmissible spongiform encephalopathies symptomatology, the final phase of the disease is interesting for Kuru - uncoilable bouts of laughter.

What is fatal familial insomnia

fatal family insomnia, prions, genes

Fatal family insomnia was diagnosed in 1986 and is due to a mutation in the PRNPgene, as a result of which one amino acid is replaced byanother. Thus, the infectious prion affects brain function, and in particular that of the thalamusresponsible for:

  • Most of the processing of sensory information we perceive is
  • Regulates the main movements we perform,
  • Affects the emotional response,
  • It controls the excitability of the cerebral cortex.

This brain structure has an essential role in sleep regulation, therefore, when infectious prions are more than normal, sleep problems begin. In the beginning, there are strange physiological disorders such as intense sweating, and then the body begins to lose weight . At some point, the initial forms of insomniacharacterized by the more difficult fall asleep aremanifested. When the condition has developed to such an extent that the patient can no longer really fall asleepat all , thiscan lead to other serious complications:

  • Chronic fatigue,
  • Sexual dysfunction,
  • Problems with blood pressure,
  • Panic disorders,
  • Disorientation, etc.

Within a year comes the flyout.

Can I get mad cow, Kuru and fatal familial insomnia

incidence of mad cow, fatal family insomnia, kuru, laughing death

Naturally, before we start thinking about whether we have mutated prion and whether we suffer from an initial degree of fatal insomnia, for example, we need to know that all three diseases in this article are in the column of extremely rare ones.

Infectious prions affect the human population anywhere in the world. There are no less or more severely affected areas. Both sexes are equally prone. Cases are described in both teenage and 70-year-olds, but the average patient tie is 45-50 years.

To our comfort, this is a group of diseases that are extremely rare.


Read more:

Autoimmune encephalitis - a crazy or treatable condition

Capgra syndrome: when we think someone else is pretending to be our loved one



  1. Prions. Proceedings of the National Academy of Sciences of the United States of America. 1998
  2. What is the difference between protein and protein
  3. How genes determine resemblance to our parents
  4. Transmissible spongiform encephalopathies. Ministry of Agriculture, Food and Forestry, Bulgarian Food Safety Agency
  5. Identification of a second bovine amyloidotic spongiform encephalopathy: molecular similarities with sporadic Creutzfeldt-Jakob disease
  6. How to deal with insomnia
  7. Fatal Familial Insomnia. Nord


The author:

👩 🔬 Yana Nencheva is a molecular biologist, Master of Biochemistry and Master of Optometry, PhD candidate in Biophysics. She has been an active organizer of a number of events since 2015, including "PhD tea" and "Eye Health Seminar", which aim to promote science in the public space. She has been the manager and co-founder of the Center for Career Guidance in Natural Sciences ScienceUp since 2019.