Fatal familial insomnia: a rare inherited disorder

Sleep is essential for our physical and mental well-being. And, yet, the Sleep Foundation estimates that 50 to 70 million people in the US alone experience sleep disturbances, with insomnia, sleep apnea, and narcolepsy being the most common. But while these conditions can significantly impact daily life, they pale in comparison to the devastating effects of fatal familial insomnia (FFI).

This extremely rare genetic disorder progressively robs individuals of the ability to sleep, leading to a fast decline in physical and mental health. Intrigued? Click through to learn more about this debilitating disorder and the ongoing efforts to find a cure.

What is fatal familial insomnia?

Fatal familial insomnia (FFI) is a rare genetic disorder that causes progressive insomnia, leading to severe sleep disturbances and eventual death.

Sleep is paramount

Sleep is vital for our overall health. It allows the brain and body to repair and recharge, leaving us feeling refreshed and alert. Insufficient sleep disrupts this critical process, impairing cognitive ability and impacting our body’s main functions.

Genetics

The disease is exceedingly rare, affecting an estimated one to two people per million annually, with roughly 50 to 70 families worldwide believed to carry the FFI gene mutation. Both males and females are equally susceptible to developing the condition.

Gene mutation

The gene mutation alters the production of prion proteins, causing them to misfold. These new abnormally shaped proteins are toxic to brain cells, leading to a progressive decline in brain function.

Visual aid

To illustrate the mutation, specialists use a simple analogy: think of when instead of neatly folding a T-shirt, you just crumple it up and throw it in a drawer. Over time, the drawer gets filled with these misshapen T-shirts, making it harder to close. Similarly, in FFI, the misfolded proteins accumulate in the brain, impairing its functions.

Dimmer switch

Deep within the brain, the thalamus plays a crucial role in regulating sleep and wakefulness. It's like a "dimmer switch," controlling the brain's activity levels. In FFI, this switch malfunctions, leaving the brain constantly active, preventing individuals from entering the deep, restorative phases of sleep.

Progressive insomnia

A core symptom of FFI is progressive insomnia, meaning the inability to sleep worsens steadily over time. Eventually, patients suffering with FFI may become completely unable to sleep.

Memory loss

During sleep, our brains solidify the connections between neurons, allowing us to learn and remember effectively. When we're sleep-deprived, these connections weaken, making it harder to focus, learn new things, and recall information.

Involuntary movements

People with FFI may experience myoclonus, which are sudden, involuntary muscle jerks or twitches. These movements occur due to disruptions in the nervous system, which can also affect a patient's coordination.

Fatal disease

FFI is a progressive and fatal disease. Most individuals with FFI eventually enter a coma-like state and, sadly, typically succumb to the disease within 12 to 30 months of the onset of symptoms.

Diagnosis

Specialists will diagnose FFI based on symptoms and the results of various tests. Click on to learn more about these tests.

Electroencephalogram (EEG)

An EEG records the brain's electrical activity through small sensors placed on a person's scalp. While not always necessary for diagnosis, an EEG may show abnormal brainwave patterns, such as slow waves or sharp spikes, which can be a sign of a prion disease like FFI.

Imaging tests

While brain MRI scans may show some general signs of brain atrophy, such as thinning of the brain tissue and enlarged fluid-filled spaces within the brain, more specialized techniques like PET and SPECT scans can reveal specific abnormalities in FFI. These scans often show reduced brain activity in key areas affected by the disease, including the thalamus.

Genetic testing

Genetic testing is crucial for confirming a diagnosis of FFI. This test identifies the specific gene mutation responsible for the disease. For families considering having children, if there's a concern about the risk of passing on genetic conditions, it's essential to discuss genetic testing options with a healthcare provider.

Ongoing efforts

Researchers are actively working towards finding a cure for FFI. In 2015, a clinical trial began testing the use of the antibiotic doxycycline to prevent the onset of FFI. This long-term study will follow 10 individuals who carry the FFI gene mutation over the course of 10 years.