Now that the finer points of kidney transplantation have been mastered, doctors are looking for ways to make young recipients grow up to be big as well as strong, virtually impossible under conventional therapy.

"You can give them a good kidney, but if we don't give them a good life, it isn't worth it," said Dr. Amir Tejani, director of renal services at the State University of New York Health Science Center in New York City.Children with kidney failure, like those with other major illnesses, tend to be shorter than normal, sometimes barely topping 4 feet as adults. Even with successful transplants, they don't come close to reaching normal size because of a steroid commonly given them along with anti-rejection drugs.

"They want to look normal. They want to feel normal," Tejani said Tuesday at the annual conference of the American Society of Transplant Physicians.

"You can't tell them the world is made up of small people when Americans are getting taller," added Dr. Ira Greifer, medical director of the National Kidney Foundation.

To help the youngsters grow, Tejani is trying to withhold the steroid, prednisone, from their post-transplant treatment. The drug usually is combined with the potent anti-rejection drug cyclosporine and inhibits the growth plate in the bone from functioning normally. It also causes acne and puffiness, most noticeably in the face.

Some children, especially girls, cheat on their medication in a desperate attempt to improve their looks, Tejani said.

"The main bugaboo of children is that they look ugly and don't grow," he said. Perhaps the best known case is that of Gary Coleman, star of the former television series "Diff'rent Strokes." The 19-year-old actor, who has undergone two kidney transplants, is less than 5 feet tall.

"It's the ones who are 5 feet that want to be 5 feet 2," Greifer said. "They would give anything for another 2 inches."

About 1,200 youngsters age 16 and under experience kidney failure every year in the United States, according to Greifer. Six hundred to 800 end up receiving new kidneys, fewer than 9 percent of the total number of kidney transplants performed annually.

Overall, transplanted kidneys were still functioning at a rate of 80 to 85 percent a year after the operation, according to Dr. John McDonald, president of the American Society of Transplant Surgeons.

Tejani said that he's tried since 1983 to remove prednisone from the treatment of 30 children whose transplanted kidneys have functioned well.