Fatal Familial Insomnia
Type of disease: Rare conditions
Fatal familial insomnia (FFI) is an inherited prion disease that affects the brain and other parts of the nervous system. Prion diseases, also known as transmissible spongiform encephalopathies (TSE), are a group of rare neurodegenerative conditions that occur when abnormal proteins clump together and accumulate in the brain, leading to tissue damage. The first symptoms of FFI usually begin in mid-life and may include insomnia that worsens over time and vivid dreams when sleep is achieved. These symptoms may be followed by high blood pressure; episodes of hyperventilation; excessive tearing; and/or sexual and urinary tract dysfunction. As the disease progresses, most affected people develop ataxia. FFI usually leads to death within a few months to a few years. Genetic prion diseases are inherited in an autosomal dominant manner and may be caused by mutations in the PRNP gene. Treatment aims at alleviating symptoms when possible.Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.