What is the definition of Fatal Familial Insomnia?
Fatal familial insomnia (FFI) affects the thalamus, the part of the brain that controls the sleep-wake cycle. Symptoms typically begin between the ages of 40-60 years. The most common symptoms are sleep disturbance, psychiatric problems, weight loss, and balance problems. Other symptoms include high blood pressure, excess sweating, and difficulty controlling body temperature. These symptoms tend to get worse over time. FFI is usually fatal in 6-36 months. Almost all cases of FFI occur due to a specific variant in the PRNP gene and are inherited in an autosomal dominant pattern. Diagnosis is based on the symptoms, clinical exam, sleep study, and imaging studies. The results of genetic testing can help confirm the diagnosis. Treatment for FFI is focused on managing the symptoms.
What are the alternative names for Fatal Familial Insomnia?
- Familial fatal insomnia
- Insomnia familial fatal
What are the causes for Fatal Familial Insomnia?
Fatal familial insomnia (FFI) occurs when the PRNP gene is not working correctly. DNA changes known as pathogenic variants are responsible for making genes work incorrectly or sometimes, not at all. In almost every case, FFI is caused by a very specific variant in the PRNP gene.
What are the symptoms for Fatal Familial Insomnia?
The following list includes the most common signs and symptoms in people with fatal familial insomnia (FFI). These features may be different from person to person. Some people may have more symptoms than others, and they can range from mild to severe. This list does not include every symptom that has been described in the condition.
Symptoms of FFI may include:
- Inability to fall asleep or stay asleep (insomnia)
- Difficulty thinking and concentrating (cognitive impairment)
- Short-term memory loss
- Weight loss
- Difficulty coordinating movements
- High blood pressure
- Inability to maintain body temperature
- Excessive sweating and tearing
The first symptoms of FFI usually begin between the ages of 40 and 60 years. Initial symptoms usually include difficulty sleeping and problems with thinking and concentration. The insomnia gets worse over time, leading to high blood pressure, rapid heart rate, weight loss, and trouble controlling body temperature. Other symptoms that may develop include uncoordinated movements (ataxia), hallucinations, severe confusion (delirium), and difficulty swallowing. Death usually occurs within 6-36 months after symptoms begin. Death is usually due to heart problems or infections.
What are the current treatments for Fatal Familial Insomnia?
Treatment for fatal familial insomnia (FFI) is focused on managing the symptoms and providing comfort for the person with FFI.
Specialists involved in the care of someone with FFI may include:
- Medical geneticist
- Social worker
Is Fatal Familial Insomnia an inherited disorder?
Fatal familial insomnia (FFI) is inherited in an autosomal dominant pattern. All individuals inherit two copies of each gene. Autosomal means the gene is found on one of the numbered chromosomes found in both sexes. Dominant means that only one altered copy of a gene is necessary to have the condition. The variant can be inherited from either parent. Sometimes an autosomal dominant condition occurs because of a new genetic variant (de novo), and there is no history of this condition in the family.
Each child of an individual with an autosomal dominant condition has a 50% or 1 in 2 chance of inheriting the variant and the condition. Typically, children who inherit a dominant variant will have the condition, but they may be more or less severely affected than their parent. Sometimes a person may have a gene variant for an autosomal dominant condition and show no signs or symptoms of the condition.