Could Sleep Myoclonus Be Life Threatening?

YES , HELLO I NEED AN ANSWER FOR WHAT MY HUSBAND IS JUST RESENTLY STATRED TO DO IN HIS SLEEP. WHICH I HAVE SEEN. AND ALSO WOKE ME FROM A SOUND SLEEP. WHEN HE SLEEPS HIS BODY JUMPS. THIS HAPPENS EVERY NIGHT NOW. WHAT IS THIS AND IS THIS LIFE THREATENING? WHAT DO WE DO?