BUFFALO, N.Y. (AP) -- Hunter Kelly, whose battle with a fatal nervous system disease inspired his Hall of Fame father Jim Kelly's charitable works, died Friday. He was 8.
Hunter's doctor, Patricia Duffner, said he died of respiratory failure.
Hunter's Hope Foundation released a statement saying the Kelly family is grateful for the support people have shown.
''It is the family's hope that all who mourn for their son, Hunter, would join them in thanking the Lord for his precious life," the statement read.
Jim Kelly, a Hall of Fame quarterback with the Buffalo Bills, established Hunter's Hope Foundation with his wife, Jill, in 1997 in honor of their son. It has raised more than $6 million and awarded more than $3.8 million to leukodystrophy and other neurological disease-related research.
Born in 1997, Hunter Kelly was given no more than three years to live after being diagnosed with Krabbe disease, an inherited degenerative disorder of the central and peripheral nervous systems. The disease hinders development of the myelin sheath, a fatty covering that protects the brain's nerve fibers.
The disease has no known cure.
The Bills, in Green Bay for a scrimmage against the Packers, released a statement expressing their condolences.
''The entire Buffalo Bills organization is deeply saddened today to hear of the passing of Hunter Kelly," the statement read. ''This courageous young man served as an inspiration to us all during his brief life. And he will forever remain a symbol of hope."
Records are scarce, but experts believe Hunter was one of the longest living of people who developed Krabbe as an infant. The disease can also develop in juveniles and adults.
Hunter spent most of his life confined to a wheelchair and hooked up to a respirator and feeding tube, while receiving around-the-clock care from his family and therapists. He was eventually able to lift his arms and head, and learned to communicate through a series of facial expressions.
He had displayed a grasp for understanding, able to comprehend stories read to him. And he recently showed a capacity for bowling, able to hold a ball, shake his hand and aim it in the direction of pins.
Jim Kelly, who helped Buffalo win an unprecedented four consecutive AFC titles in the early 1990s, had credited his son for serving as his inspiration after he retired from football following the 1996 season.
''He'll never be able to do what daddy did," Kelly said last year. ''But he's going to do greater things. He's going to make a difference in kids' lives. He already has."
He also paid tribute to Hunter in his Hall of Fame acceptance speech in 2002.
''It has been written throughout my career that toughness is my trademark," Kelly said. ''Well, the toughest person I've ever met in my life is my hero, my soldier, my son, Hunter. I love you, buddy."
Kelly and his son shared a birthday -- Valentine's Day.
Duffner credited the Kelly family for Hunter living well beyond the initial prognosis and for its help in Krabbe research.
''He was such a brave little boy. ... He was a tough kid, like his dad," Duffner said. ''It's really quite remarkable how one family has changed the course of a disease."
She noted that New York will begin screening newborns for the disease, something which the foundation has long favored. If caught just after birth, an umbilical cord blood transplant can halt its effects.
The Kellys will hold a public memorial service Tuesday in Hamburg, N.Y., and ask that donations be made to the Hunter's Hope Foundation.