When the son of David Vermeire, Hermitage physician and a former long-time Hermitage school board member, was diagnosed with myasthenia gravis, Vermeire found out his son was not alone in Mercer County.

And the number of county residents who have been diagnosed with what is sometimes called the rag doll disease may be a cause for concern, Vermeire said.

Myasthenia gravis is an autoimmune disorder in which the immune system destroys receptor cells in the muscles so the nerves cannot stimulate the muscles to work.

The nerves normally provide signals to the muscles, but the muscles don't have the receptors to stimulate the muscle.

"We have about 25 cases in Mercer County and about 18 or 19 in the Shenango Valley," Vermeire said. "And we're about 50 percent above the national average in the valley. And I'm sure there are more cases in the county that I don't know about."

According to statistics that Vermeire got from the Myasthenia Gravis Foundation of America, Inc., there are about 25 cases for every 100,000 people. The Shenango Valley has about 44,000 people, and 18 or 19 cases in the valley makes the incidences of the disorder about 45 for every 100,000.

His journey to discover more information about the autoimmune disorder began around August 1999, when his then 18-year-old son, Jeff, was diagnosed.

"To the best of our knowledge, he began to get symptoms in 1998 -- when he was a junior in Hickory High School," said Vermeire, adding that his son had a problem with weakness after a district tennis meet.

Symptoms can include drooping eyelids, double vision, difficulty swallowing, general weakness and drooping of facial muscles.

Vermeire compared it to a television set: "If you have a nice antenna, you can get the waves coming in and get good reception. With rabbit ears, it's not going to pick up the signal as well and you'll have bad reception."

Following his son's diagnosis, Vermeire later found that two other Hermitage students were diagnosed with the disorder.

Kisha Doutt, a 2001 Hermitage High School graduate, and Courtney Ivan, a 2000 Hermitage High School alumnus, were also diagnosed with myasthenia gravis -- Ms. Doutt in 1998 and Ms. Ivan in 2001.

"When Courtney was diagnosed, we began to ask questions," said Vermeire, adding that though the three were in school together, there wasn't any one common denominator."

The cause of the disease is unknown, as well as the reason why there is such a high incidence in this area.

"We all wonder, is it environmental in nature, is it something in the air, the water or the soil?" Vermeire said. "We've had many industries around here for many years. There has been pollution of our air and water supply. In recent years there have been improvements to clean it up, but what went on 34 years ago when these things were in full bloom?"

He also added that though there is speculation about the school renovation and expansion project being part of the cause, two of the students were diagnosed before the renovations began.

"But three students who were in school at the same time -- you have to wonder," Vermeire said.

Although the cause is unknown, myasthenia gravis has some distinguishing factors. For example, many people who have the disease have an enlarged thymus gland, Vermeire said.

The thymus gland, which stimulates the immune system, is located behind the breastbone and usually deteriorates throughout childhood.

"Adults have very little of a gland left," Vermeire said. In some people with myasthenia gravis, the thymus gland enlarges over a few years.

Many people with myasthenia gravis have their thymus glands removed. When Vermeire's son, Jeff, had it removed, it extended the length of his breastbone when, at his age, it should have been almost gone.

Other factors that may contribute toward the disease are stress, other illnesses, injury or surgery or anything that may have damaged the immune system.

Myasthenia gravis patients in crisis may also be put on a respirator, Vermeire said. Fortunately, this has never happened to Jeff.

Myasthenia gravis patients can go about daily activities, but "they can't go full tilt," Vermeire said. "They have to learn what their limits are. They have to learn to limit their activities so they can be healthy."

In the meantime, Vermeire is starting a local support group for those with the disorder or for those wanting information about the disorder. The first meeting will be at 6 tonight at the Suburban Restaurant in Hermitage.

"If we can find a common thread, that would be wonderful," Vermeire said. "At least that would help direct us where we could be looking."

For more information about the support group, call (724) 342-6200.