SNP Shot: Genomic Insights

Narcolepsy is a long-term sleep disorder that throws off the regular cycle of sleeping and waking. It can start at any age, but it's most common in teenagers.

A key symptom of narcolepsy is feeling extremely sleepy during the day. People with narcolepsy are constantly tired and have sudden, overwhelming urges to sleep throughout the day. These "sleep attacks" can happen at any time, even during activities like eating or talking. They usually last for a few seconds or minutes and are often followed by a nap, after which the person feels refreshed.

Another frequent symptom is cataplexy, a sudden loss of muscle control triggered by strong emotions such as laughter, surprise, or anger. During these episodes, individuals might slump or fall, sometimes leading to injuries. Cataplexy episodes usually only last a few seconds and can occur several times a day or only a few times a year. Most individuals diagnosed with narcolepsy experience cataplexy. However, some do not, leading researchers to differentiate between two main types of the condition: narcolepsy with cataplexy and narcolepsy without cataplexy.

Narcolepsy also impacts sleep at night. Most individuals struggle to sleep for more than a few hours. They often experience vivid hallucinations when falling asleep (hypnogogic hallucinations) or waking up (hypnopompic hallucinations). They may also have intense, disturbing dreams and physically act them out by moving or talking in their sleep. Many individuals also experience sleep paralysis, a temporary inability to move or speak while falling asleep or waking up. The combination of hallucinations, vivid dreams, and sleep paralysis can be frightening and unpleasant.

The severity of narcolepsy varies; some people experience all the major symptoms, while others have only one or two. While the signs and symptoms are usually lifelong, the frequency of cataplexy episodes may decrease with age and treatment.

Inheritance:

In most instances, narcolepsy appears randomly in individuals with no family history of the disorder. A small percentage of cases are reported to occur within families; however, there is no clear inheritance pattern. Individuals who are closely related (parents, siblings, and children) to someone with narcolepsy with cataplexy have a significantly higher risk (40 times greater) of developing the condition compared to the general population.