Investigators on Monday were trying to determine what exactly killed a 5-year-old Queens boy, a day after he was found unconscious in his Jamaica home.

The boy, Michael Guzman, was found unresponsive at his home on 109th Avenue at about 4:15 p.m. after his mom called 911, police said. He was taken to Jamaica Hospital Medical Center, where he was pronounced dead, they said.

Guzman had no obvious signs of trauma, a police source said, and suffered from epileptic seizures.

Police also questioned Guzman’s parents on Monday in connection with his death.

Over the years, the Administration for Children’s Services had opened up 13 cases involving the family, five of which were determined to be unfounded, a police source said.

Guzman’s mother told investigators she gave the little boy his epilepsy medicine before she left him with his five siblings at around midnight to go to a friend’s house, the source said. When she got home at about 2:30 a.m. on Sunday, she found Guzman sleeping, intertwined on the couch with one of his siblings.

Guzman might have been having trouble breathing at the time, she told police, because he apparently said he was in pain, but was able to get up and walked to bed on his own, the source said.

His mother then told police she found the boy unconscious in his bed with vomit coming out of his mouth the next day. The medical examiner estimated that he had been dead for about 12 hours, the source said.

No arrests had been made as of Monday evening.

The medical examiner will determine the cause of death.