Although Delante Resper suffered from asthma and curvature of the spine, the enthusiasm with which the eighth-grader rode his wheelchair to classes at J. Hayden Johnson Junior High School in Southeast Washington made most people think that he was okay.

"I nicknamed him 'Speedy' because of the way he flew up and down the hallway," said Michael Berry, a security guard at Johnson. "If you asked him what was wrong with him, he'd say, 'I'm just small for my age,' and keep on rolling."

It wasn't until Delante, 13, suffered a stroke at school last month, then two more at Children's Hospital, that doctors discovered the cause of his health problems: Delante had progeria, a rare genetic disease that accelerates the aging process to about seven times the normal rate.

The boy's internal organs were what you'd expect to find in a 90-year-old man.

Only after his death Jan. 4 from that massive third stroke did people learn just how courageous Delante really was and what a precious gift his life had been for those who knew him.

"The only time he'd miss school was when he had a doctor's appointment," said Robert Gill, the principal at Johnson. "I don't know how many 90-year-old men would go to work in a wheelchair every day. But Delante would not give in."

In November, teenagers at Johnson -- who already were wary of developing close friendships because of previous losses to violence -- became even more reluctant when one of their classmates, 14-year-old Erica Herring, was fatally shot by another 14-year-old while sitting in a van.

But in Delante, they could see someone cope with grief and pain and still have faith and close friends. Students reached out to him, served him lunch from the school cafeteria and included him in conversations.

For even the most disparaging of students, it was impossible to stay stuck in a rut while watching someone who could neither run nor play still manage to laugh and delight in life.

"Having him at Johnson brought all of us to a higher level of caring," Gill said. "He brought out the best in us."

Hundreds of mourners gathered for Delante's funeral at Johnson Memorial Baptist Church in Southeast on Saturday. Many were stunned to learn about the premature aging that had taken his life.

"He would always call adults by our first names," recalled Freda Newby, Delante's aunt. "Now I wonder if that was because he knew he was older than all of us."

With progeria comes wrinkled, aged-looking skin, baldness and a pinched nose. Mental growth is said to be equivalent to that of other children of the same age. But Delante's family members are not so sure about that and thought, even before his death, that he was wise beyond his years.

"I was amazed at the things he could do in spite of his disabilities," said Jackie Resper, Delante's mother. "He was a computer whiz even though he never had formal training. His mind was so sharp that if you said something that didn't sound right, he'd respond like a grown person."

Resper remembered Delante's reaction last year when she told him she was engaged and that her fiance, who lived in Ohio, was planning to quit his job and move in with them.

"He gave me this incredulous look and said, 'Hello? What about rent, food and utilities?' You expect a response like that from your parents, not from your 13-year-old son."

When Delante's aunt and grandmother told him that they were about to purchase their first homes, Resper said, "He joked, 'Why y'all wait till you get so old to buy a house?' His grandmother would say that he sounded like he had been here before."

For Delante, this school year began on a high note because he had a new, more powerful wheelchair. School guard Berry decorated it with blue fog lights and a siren. By December, however, Delante was experiencing severe headaches. He was especially lethargic on the day of the school's Christmas party but insisted on going.

"He said, 'I'm not missing the party after I've paid my $5,' " Resper recalled.

He not only made it to the party, he was the life of it.

E-mail: milloyc@washpost.com.