Health Talk: Fatal Familial Insomnia
Many people have had trouble sleeping at one point or another during their lives. Indeed, not being able to get enough sleep is a common problem among university students. However, insomnia is also the primary symptom of a rare, genetic prion disease, fatal familial insomnia.
Fatal familial insomnia (FFI) is notable for the prognosis of those suffering from it: as the disease progresses, patients find themselves able to get less and less sleep, until they are unable to sleep at all, and eventually succumb to exhaustion.
There is no known cure for FFI. Sleeping pills have proven ineffective in inducing sleep in patients suffering from the illness. However, there is some evidence that treatments aimed at mitigating symptoms due to the associated insomnia may improve the quality of life of such patients.
People who suffer from fatal familial insomnia generally begin to present symptoms around middle age, between the ages of 40 and 60.
The late onset of the disease often means that those suffering from FFI have already passed on the responsible gene to their children by the time that they are aware that they possess it.
FFI is an autosomal dominant disorder. This means that to have the disease, one must possess just one copy of the gene responsible, rather than two, and that the gene does not lie on a sex chromosome and hence has equal chances of being passed onto males and females.
Genetic tests have been developed to detect the presence of the disorder, and research to find a cure is ongoing. Some researchers hope that any progress made toward finding a cure for FFI may prove valuable in understanding similar diseases and other neurological maladies.
As its name suggests, the disease is fatal, and patients succumb to the disease generally within several months to several years of the onset of symptoms. Patients suffer from the degeneration of a specific part of the brain, the thalamus, which is in part responsible for the regulation of sleep. This leads to symptoms including insomnia, panic attacks, lethargy, hallucinations, and phobias, which are followed by a complete lack of sleep, weight loss, apparent dementia, the shut-down of bodily function, and finally, death.
The symptoms of FFI originate from damage to the brain caused by prions. Prions are abnormally folded proteins that are able to self-replicate by inducing normal proteins to fold abnormally as well. In those with FFI, a mutation in the gene coding for the protein causes the subject’s body to produce the abnormal protein responsible for the disorder.
Prion diseases, also called transmissible spongiform encephalopathies, are defined by the Centers for Disease Control as “a family of rare progressive neurodegenerative disorders that affect both humans and animals.” Several common characteristics of these diseases include a long incubation period, a characteristic pattern of neural loss in the brain, and the lack of an inflammatory response by the patient’s body. There is currently no known cure for prion diseases. Examples of prion diseases other than fatal familial insomnia include Creutzfeldt-Jakob disease and kuru — once common among the Fore tribe of Papua New Guinea, kuru’s transmission was primarily due to cannibalism — in humans, and bovine spongiform encephalopathy, popularly known as “mad cow disease,” chronic wasting disease, and scrapie in animals.
According to a Dateline NBC article, there are 28 families with a history of FFI worldwide, although more instances of the disease are being uncovered. In January 2003, the Fatal Familial Insomnia Families Association was founded in Treviso, Italy, with the goals of promoting research efforts, publicizing recent findings, supporting those affected by FFI, and encouraging communication between families affected by the disorder.
The Fatal Familial Insomnia Families Association currently supports the initiation of research into the clinical management and molecular study of FFI, as well as the establishment of preventative treatments for people who carry the genetic mutation responsible for the disease.