Fatal familial insomnia is aextremely rare inherited diseasewhich belongs to the group of pathologies known as transmissible spongiform encephalopathies. It produces a degeneration of the nervous system that is manifested by asevere disturbance of the circadian rhythm (sleep-wake rhythm), accompanied by ataxia (lack of coordination of muscular movements) of progressive severity, as well ashyperthermia and sweatingand endocrine disorders. Theinsomniait progressively deteriorates the health of the person who suffers it until it makes him go into a coma and cause death.
Fatal familial insomnia was first described in 1986 in an Italian family from the Veneto region. It affects both sexes and normally appears in adulthood, although cases of infantile and juvenile appearance have been described. To date, some twenty affected families have been identified in Spain.
The main manifestation is theprogressive and untreatable insomnia: the patient is unable to fall asleep, although he wants to do so, he closes his eyes and tries to fall asleep, hallucinations and respiratory crises return him to a waking state. Cognitive functions are irreversibly altered, with attention and memory disorders, depression and behavioral disorders, which is why in the past these patients were considered insane. The disease also causes endocrinological alterations that are due to theloss of circadian rhythm in the secretion of certain hormones such as melanin, prolactin, and growth hormone, in addition to increased secretion of cortisol (the stress hormone).
As with so many other rare diseases, there is currently no treatment that can cure or control fatal familial insomnia.
Symptoms
Symptoms vary from person to person. They tend to appear between the ages of 32 and 62. However, they may start at an earlier or younger age. Possible symptoms include:
– Difficulty getting to sleep
– trouble falling asleep
– muscle spasms
– muscular stiffness
– movement and kicking when sleeping
– loss of appetite
– rapidly progressing dementia
Symptoms of more advanced fatal familial insomnia include:
– inability to sleep
– impaired cognitive and mental function
– loss of coordination or ataxia
– increased blood pressure and heart rate
– excessive sweating
– difficulty speaking or swallowing
– unexplained weight loss
– fever
Causes
It is caused by a mutation in the PRNP gene. This mutation causes an attack on the thalamus, which controls sleep cycles and allows different parts of the brain to communicate with each other. It is considered a progressive neurodegenerative disease. This means that the thalamus gradually loses nerve cells. It is this loss of cells that leads to the range of symptoms of fatal familial insomnia.
The genetic mutation responsible for this disease is passed down through the family. A parent with the mutation has a 50% chance of passing the mutation to their child.
Treatment
As we have discussed, there is no cure for this genetic prion disease . Few treatments can effectively help control symptoms. Sleep medications, for example, can provide temporary relief for some people, but they don’t work in the long term.
However, researchers are actively working towards effective treatments and preventive measures. A 2016 animal study suggests that immunotherapy may help, but additional research is needed, including human studies.
Living with the disease
It may take years before symptoms of the disease begin to appear. However, once they start, they tend to get worse quickly over the course of a year or two.
