The actor Cameron Boyce, 20, who died on Saturday, had epilepsy, and his death was caused by a seizure that occurred during his sleep, his family said in a statement.

Mr. Boyce starred in shows on the Disney Channel, including “Descendants” and “Jessie,” and appeared in a number of movies.

“Cameron’s tragic passing was due to a seizure as a result of an ongoing medical condition, and that condition was epilepsy,” a Boyce family spokesperson told ABC News in a statement on Tuesday night. The Los Angeles County coroner’s office conducted an autopsy, but said it was awaiting the results of additional tests before determining an official cause of death.

The most likely cause of his death was Sudep, or sudden unexpected death in epilepsy, said Dr. Orrin Devinsky, director of NYU Langone’s Comprehensive Epilepsy Center in Manhattan. He was not involved in Mr. Boyce’s care.