#13-year-old battling COVID-19-like symptoms actually died of rare heart condition

A 13-year-old California boy who died while battling coronavirus-like symptoms did not die of COVID-19 after all, officials said.

Maxx Cheng died of a rare heart condition while self-quarantining July 16 in his room due to symptoms that his family thought may have been from the virus, CBS LA reported.

The Los Angeles County Medical Examiner listed the primary cause of death as cardiac tamponade, which causes blood or fluids to build up in the space around the heart, putting pressure on the organ.

He also suffered from a genetic mutation associated with Loeys-Dietz syndrome, a condition characterized by an enlarged aorta, the blood vessel that distributes blood from the heart to the rest of the body.

Cheng had started to feel ill on July 4 when he came down with symptoms including nausea, vomiting and chest pains, the outlet reported.

His mom took him to get tested for the coronavirus on July 9, though his results came back negative.

“His symptoms matched, but then the test came out negative. So we were a little bit confused,” his sister, Charlotte Cheng, told the outlet.

Skeptical of the results, the family had him continue to isolate in his room, the outlet reported.

He started to feel better but then days later, he was discovered unresponsive.

“We went to go check up on him, like we normally do [and] he wasn’t answering,” his sister said.

“We found him passed out in the room.”