ST. PETERSBURG, Fla. — Jacquez Welch was a star athlete on the gridiron for St. Petersburg Northeast High School and also a star pupil in the classroom.

That's the legacy he will leave behind as his life was cut short early due to the sudden onset of what doctors diagnosed as a congenital condition.

• Northeast High football player taken off life support
• Jacquez Welch, 17, collapsed after tackle during game Friday night
• Doctors tell his mother he had a pre-existing brain condition

According to Welch's mother, Marcia Nelson, Welch is "completely brain dead." She reported her son's condition during a gathering of the Northeast High School community at Gateway Baptist Church Monday evening.

Nelson went on to say that Welch's organs would be donated to help others. Already seven candidates for organ transplant had been identified whose lives could be saved thanks to the donation.

Nelson also expressed hope that more could be learned about the condition that ended Welch's life, to prevent other families from going through what her family and this community is going through.

"Looking for out of this, to be honest, to do research on what he had," she said. "It's[sic] no research on what he had, it's no side effects of what he had. You would not know until you drop with it."

Welch, 17, stumbled after a tackle during Friday night's game against Seminole Osceola High School and didn't get up.

Nelson watched it happen.

"It was a group tackle. Everybody got up. He got up a little slow and he didn't get back up," she said.

But she was adamant when she said Monday that she hoped her son's death would not discourage anyone from playing football.

"I don't want to see nobody afraid to play no sport, because they said if he was walking down the street not doing nothing he could have fell out," she said.

Doctors at Bayfront Health hospital told Nelson that the tackle had little do to with her son's injury. They say Welch has a pre-existing condition called an arteriovenous malformation in his brain, which is an abnormal tangle of blood vessels.

"It was something he couldn't control, nobody could control, so it's keeping me calm and understanding... what happened," Nelson said. "Tragedy happened, but it was a cause that I couldn't control, so maybe that's more why I'm a little calmer."

It's a calm that has become a source of strength for everyone who knows Welch.

"I'm just so proud of him. I just made sure I told him that every time I'd see him. I love you. I'm just so proud of you. He was the perfect son," said the man who raised him, Tory Larkins.

"I was a lucky man, not an unlucky man, because I got to be with Jacquez," Northeast High Coach Jeremy Frioud said. "I got to impact Jacquez and Jacquez got to impact me. So that's how the football team and how we're looking at it."

Nelson, for her part, said her support for the team is unwavering, even in the face of tragedy.

"I will be at every game until whenever because these are boys out here who became my new sons so I’m there for the long run," she said.

More about Arteriovenous Malformation

We looked into what might cause a brain arteriovenous malformation, or AVM.

An AVM disrupts the normal process of blood flow through your brain. The condition occurs when blood goes from your arteries directly to your veins through abnormal vessels.

Bayfront Health neurosurgeon Dr. Kirk Jobe told us the condition is very rare. He said 1 in 10,000 have the condition.

Symptoms include seizures or stroke-like symptoms.

The condition develops at birth and those with it have a two to four percent chance each year of having a rupture.

A rupture is most likely to occur in patients 30 to 40 years of age.

Jobe went on to say that the condition is not only rare, but unique to each patient, making it very unpredictable. 

“He could've had this getting up on a Saturday morning and having breakfast. He could have had it while having a morning jog or out for a swim,” said Jobe.  “So, it's literally one of those things that are a ticking time bomb in the head and there's no way to predict when this could happen or which people are walking around with this."

Finally, Jobe said family health history does not necessarily increase a person's chances of having an AVM.