John Travolta described Wednesday how he desperately tried to save the life of his seizure-prone son and made perhaps his first public description of the teen as autistic as he testified in the trial of two people accused of trying to blackmail him.

With his wife, Kelly Preston, looking on inside the Nassau, Bahamas courtroom, Travolta said that he performed CPR on his son after a nanny alerted him the teen had fallen ill at a family vacation home on Grand Bahama island. Jett Travolta later died from a seizure.