Sleep Paralysis: Hereditary?

This is a great question. A definitive, positive answer could possibly lead to help for those who experience chronic Sleep Paralysis. I'm currently looking for real research and findings on the subject on a hereditary link.

My grandmother (father's mom), father, mother, and sister have all experienced Sleep Paralysis, while only my grandmother and mother have experienced Exploding Head Syndrome.

The Cleveland Clinic had this to say about Sleep Paralysis:

People with sleep paralysis are not able to move the body or limbs when falling asleep or waking up. Brief episodes of partial or complete skeletal muscle paralysis can occur during sleep paralysis. Sometimes sleep paralysis runs in families, but the cause of sleep paralysis is not known. Sleep deprivation and irregular sleep-wake schedules can also cause sleep paralysis. It is also seen in narcolepsy, a disorder characterized by severe excessive daytime sleepiness. This disorder is not harmful, but people experiencing sleep paralysis often are fearful because they do not know what is happening. An episode of sleep paralysis often is terminated by sound or touch. Within minutes, the person with sleep paralysis is able to move again.

The complete page of information on Sleep Paralysis and other parasomnias from the Cleveland Clinic can be found ***here***.

Oh, in case you haven't heard the word "parasomnias" before, here is the definition from WebMD:

Parasomnias are disruptive sleep-related disorders that can occur during arousals from REM sleep or partial arousals from Non-REM sleep. Parasomnias include nightmares, night terrors, sleepwalking, confusional arousals and many others.