Marathon Marvel

Monday, April 16th 2001, 12:00 am

By: News On 6

HOPKINTON, Mass. (AP) _ Katie Lynch spends most of her time in a wheelchair or on a walker. On Monday, tears trickled down her face and the crowd erupted in cheers as she crossed the finish line of her own Boston Marathon _ 26.2 feet from the start.

``I was nervous like any other marathoner, but it was a good nervous energy,'' she said. ``I don't think it could have been more satisfying.''

Lynch, 26, weighs 35 pounds and stands 28 inches tall. She has a unique, unidentified form of dwarfism and suffers from circulatory problems and back pain.

Yet on Monday, she dressed as any marathoner would _ with a cap, sneakers and racer number 2001 pinned on her shirt _ and took her mark at the starting line before the rest of the race got started.

Leaning on a tiny walker with wheels, and supported on either side by her two brothers, she walked the first 26.2 feet of the Boston Marathon route. The starting line is in Hopkinton, 26.2 miles from downtown Boston.

``It was the most amazing thing,'' she said.

Lynch had been training for her marathon by walking 100 feet, in 10-foot increments. She had hoped to finish her 26.2 feet in 15 minutes; she completed it in less than 1 minute.

``With Katie, you never know what to expect,'' said her brother, Wyeth Lynch. ``She surprises us all the time.''

Lynch was only 13 inches long and weighed 4 pounds 13 ounces when she was born. Doctors wrongly diagnosed her as retarded and predicted she would die young.

But her parents tried to provide a normal family life, and Lynch graduated with honors from high school, where she managed the women's indoor track team and wrestling team. She graduated with highest honors from Regis College and now works at Boston Children's Hospital as an advocate for sick children and their families.

She also moonlights as a motivational speaker, championing the cause of the physically challenged.