Fatal familial insomnia: symptoms, causes, life expectancy

Fatal familial insomnia: symptoms, causes, life expectancy

Fatal familial insomnia (FFI) is a rare disease that disrupts sleep and impairs cognitive functions. When the first symptoms appear, patients have a life expectancy of a few months. Symptoms, causes, prevalence in the world and in Europe, treatment… Here is everything you need to know about this fatal disease with Dr Jean-Philippe Brandel, neurologist, and Virginie Duigou, president of the Neuro IFF Europe and diseases association let’s pray.

What is fatal familial insomnia?

Fatal familial insomnia is a prion disease, also called subacute transmissible spongiform encephalopathy (TSE). These rare diseases are characterized by rapid and fatal degeneration of the central nervous system. The best known is Creutzfeldt-Jakob disease (CJD). “Fatal familial insomnia is the latest disease to join the group of prion diseases. It was first described in Italy in 1986.says Dr. Brandel.

Prion diseases are caused by the accumulation in the brain of a protein, the prion protein, which leads to the accumulation of aggregates harmful to neurons. Currently, there is no treatment that can cure these diseases.

What is the cause of fatal familial insomnia?

IFF is a genetic disease. It is linked to the mutation of a gene on chromosome 20 (D178N, associated with codon 129 encoding a methionine). This genetic mutation is inherited from one parent. For IFF, we speak of a hereditary disease with dominant transmission. In other words, to develop the disease, you just need to carry one copy of the mutated gene. Also, a sick person has a 50% risk of transmitting the disease with each pregnancy. “It only takes one parent to have this genetic mutation to have a 1 in 2 risk of transmitting the disease to their children.explains the neurologist.

How many cases in Europe?

Prion diseases are rare diseases since there are 2 cases per million inhabitants per year. Fatal familial insomnia is a very rare disease with only 198 cases worldwide in 2018. “In Europe, we identified 22 cases between 1992 and 2016”, points out Dr. Brandel.

What are the symptoms of fatal familial insomnia?

As its name suggests, IFF disrupts sleep and results in deterioration of cognitive functions and loss of coordination. Early symptoms are minor difficulty falling asleep and staying awake, sometimes accompanied by contractions, spasms and muscle rigidity.

Sleep gradually becomes impossible, we then speak of severe insomnia. “Patients hardly sleep anymore and have visual hallucinations. Added to this are neurodegenerative disorders such as fever of neurological origin, drops in blood pressure or, on the contrary, an increase in blood pressure accompanied by profuse sweating, respiratory disorders and intellectual disorders., explains the specialist. Gradually, movement disorders and dementia appear.

The permanent lack of sleep ends up plunging the patient into a form of coma linked to significant damage to the central nervous system.

What life expectancy?

IFF generally begins around age 50. But in some patients, the first symptoms may appear earlier or later. “The progression of this disease is rapid, the average survival time is between 12 and 18 months.says Dr. Brandel.

How to diagnose fatal familial insomnia?

The diagnosis is based on the observation of clinical signs (symptoms mentioned previously) and on carrying out an MRI on which certain anomalies are identified in the thalamus (area located at the base of the brain). A lumbar puncture may also be done to look for abnormal proteins in the spinal fluid.

The diagnosis of fatal familial insomnia is confirmed by genetic testing.

What is the treatment for fatal familial insomnia?

There is no treatment to cure the disease. Treatment for IFF relies on supportive measures that aim to relieve symptoms and make the patient feel as well as possible.

Experiments have tested measures to help people sleep, but the benefits have only been temporary.

How do you know if you have fatal familial insomnia?

If a close relative (father, mother, aunt, uncle, brother or sister) has developed the disease, there is a significant risk that you carry the genetic mutation responsible for the development of IFF. To find out, you can, if you are an adult, carry out a pre-symptomatic test to find out your genetic status.

This is a classic blood test but the results are not without consequences. “This pre-symptomatic testing process is based on several consultations supervised by a multidisciplinary team made up of a geneticist, psychologists and psychiatrists. This is a very difficult process for those affected. Some go through with the process while others choose to stop because they prefer not to know.”explains the neurologist.

Can we prevent the transmission of the disease to our children?

For those who have inherited the familial mutation, it is possible to stop transmission of IFF for future pregnancies.

  • The first option is the prenatal diagnosis. It consists of collecting and analyzing embryonic cells. If the mutation is present in the embryo or fetus, termination of pregnancy for medical reasons may be offered to the future parents. In the absence of a genetic mutation, the pregnancy continues;
  • The second option is the pre-implantation diagnostics. In this case, pregnancy is possible thanks to in vitro fertilization (IVF). Cells are collected from the embryo to do the genetic test. If the embryo carries the genetic abnormality, it is not implanted in the mother’s uterus. If it is non-carrying, it is re-implanted into the mother’s uterus.

Neuro IFF Europe: the first association dedicated to the disease

The Neuro IFF Europe and prion diseases association is the first patient association created by families and loved ones of people affected by fatal familial insomnia. TipsForWomens interviewed its president, Virginie Duigou, who witnessed the disease on several occasions since her aunt, her brother and her mother died from it, at 57, 21 and 63 years old respectively. Her sister, aged 35, carries the genetic mutation but is not sick. Virginie, for her part, does not know if she is a carrier of the mutation since she did not wish to take a pre-symptomatic test to find out her genetic status.

Since the death of her mother in March 2023, Virginie has put all her energy into creating the first association dedicated to IFF (and recently expanded to prion diseases). “The objectives of the Neuro IFF Europe and prion diseases association are to raise awareness about the disease, to bring together patients and their families, but also to help and advance research”explains Virginie Duigou.

The young woman’s tireless efforts, carried out for only a few months, have paid off since the association is today a member of the Rare Disease Alliance and this year attended the annual World Congress on Prions which was held at the Portugal. Virginie and the other members of the association also carried out several actions to raise funds during the last edition of the Telethon. “We are now trying to set up a scientific council and we would like, in the near future, to launch calls for research projects.”, confides the president of Neuro IFF Europe and prion diseases.