A rare and deadly disease usually manifests itself around the age of 40 and is inherited from a parent’s genes. Patients enter a coma-like state and die within nine to 30 months of the onset of symptoms.
A fatal familial insomnia (FFI) is a rare genetic disease that affects the ability to sleep, ultimately leading to the death of 1 to 2 people per million annually.
The neurodegenerative disease is associated with a mutation in the PRNP gene, which produces prion proteins. These misfolded proteins are toxic to brain cells, particularly in the thalamusa region responsible for regulating sleep, temperature and appetite.
The disease is inherited in an autosomal dominant manner, meaning children need only one copy of the mutated PRNP gene from one of the parents to develop the disease. Approximately 50 to 70 families worldwide carry the mutation, and men and women are equally affected. In rare cases, individuals with no family history may spontaneously develop the mutation, allowing them to pass it on to their descendants.
The symptoms
The most characteristic symptom of FFI is the worsening of insomniawhich progresses to the point where patients cannot sleep… for the rest of their lives.
Other symptoms include memory loss, high blood pressure, hallucinations, muscle tremors, excessive sweating e loss of coordination.
The onset of the disease normally occurs around the age of 40, although cases have been recorded from the age of 20 or 70. As time passes, the patients enter a coma-like state and succumb to the disease within nine to 30 months after the onset of symptoms.
There is no cure (and treatment is challenging)
There is currently no cure for FFI and treatment focuses on managing the symptoms. Medicines like clonazepam can relieve muscle spasms, and other strategies, such as rigorous exercise and narcoleptic medications, have been used to prolong patients’ lives.
A 2006 case cited by demonstrated that these approaches prolonged the life of a 52-year-old patient by about a year.
In 2015, a clinic was started that explores the use of doxycyclinean antibiotic that prevents the formation of misfolded proteins in another prion disease, Creutzfeldt-Jakob disease, better known as mad cow disease. The trial involves 10 individuals with the FFI mutation and aims to evaluate their prognosis and survival compared to previous cases.
