Fatal familial insomnia

Fatal familial insomnia (FFI) is a very rare, autosomal dominant inherited, disease of the brain. It is caused by a mutation in a protein called prion protein (PrP): asparagine-178 is replaced by aspartic acid. The mutation changes the shape of PrP so that it becomes a prion and makes other, normal PrP molecules change to the abnormal shape. This causes amyloid plaques in the thalamus, the region of the brain responsible for regulation of sleep patterns. The dysfunction of the thalamus results in insomnia first of all, which progresses to more serious problems over several years. The age of onset is variable ranging from 30 to 60. Death usually occurs within 3 years of onset. more...

The presentation of the disease varies considerably from person to person, even among patients from within the same family. Common symptoms and signs include:

• intractable insomnia
• dysfunction of the autonomic system - causing hyperthermia, hypertension, tachycardia, tachypnea and hyperhydrosis
• dementia
• motor paralysis.

There are other "prion diseases" with different symptoms, such as Creutzfeldt-Jakob disease (CJD) and new variant CJD (vCJD) in humans, bovine spongiform encephalopathy (BSE) in cows, and chronic wasting disease in American deer and American elk (in some areas of the Rocky Mountains). FFI, as with other prion related diseases, is ultimately fatal and incurable. Hopes rest on the so far unsuccessful gene therapy and possibly drug development.

Other spongiform encephalopathies

• In humans
  • CJD Creutzfeldt-Jakob disease
  • GSS Gerstmann Sträussler Scheinker syndrome
  • FFI Fatal familial insomnia
  • Kuru
  • Alpers syndrome (hypothesized)

• In other vertebrate animals
  • BSE Bovine spongiform encephalopathy in cows
  • TME Transmissible mink encephalopathy in mink
  • FSE Feline spongiform encephalopathy in cats

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