Perhaps no one more appreciates the success of the play, "The Elephant Man" and its movie version than Mary Ann Wilson and the people with whom she meets every other month. Their lives have all been touched in some way by nbeurofibromatosis, the same disease that so hideously disfigured John Merrick, the Victorian medical curiosity and side-show attraction who was the Elephant Man.

Although neurofibromatosis -- NF -- is more common than muscular dystrophy and cystic fibrosis combined, little is known about this genetic disorder that affects an estimated 100,000 Americans today.

"It's the most overlooked common serious disorder in history," says Wilson, who founded the local chapter of the National Neurofibromatosis Foundation from her Mitchellville home nearly two years ago, and whose 10-year-old son John suffers from the disease. "We're asking the same questions and getting the same answers, and it's been over 100 years since John Merrick," she says.

Part of the reason NF has attracted so little scientific research and public attention in the past is that it usually is not life threatening, says Dr. Judith Bader, medical coordinator of the Inter-Institute Genetics Clinic at the National Institutes of Health. The cause has not attracted patrons willing or able to sponsor national telethons and other fund-raisers.

Since the play and movie "The Elephant Man" came to Washington theaters last year, however, the foundation has been overwhelmed by the public response, Wilson said. The number of persons in the area known to have the disease has more than doubled, symposia and medical articles on the subject have been published, and proposals for grants to NF research have increased.

Membership in the foundation has increased dramatically. The local chapter now includes in its membership 100 families, compared with 40 a year ago. The five chapters in the United States now have 418 families as members.

There is no cure for neurofibromatosis. Treatment usually consists of surgery -- either to remove the tumors characteristic of the disease or to correct the bone malformation that sometimes develops. One of several places where intensive research is being conducted is the National Institutes of Health, where patients and their medical histories are studied at weekly clinics, in a search for new information about the genetic aspects of the disease.

Like other genetic disorders, neurofibromatosis is hereditary. Parents who carry the gene have a 50 percent chance of passing it on to their children. wDoctors estimate, however, that half of all NF cases are "spontaneous mutations," in which the patients developed the disease although their familes had no history of it.

Symptoms usually begin in early childhood or adolescence, but can occur as late as age 50. Characteristic signs in the adult are coffee-colored spots on the skin (cafe-aulait spots), usually six or more; multiple benign tumors that usually develop just under the skin and, often, abnormal curvature of the spine. Doctors believe most NF patients will have normal life spans. Most are able to lead normal lives, but in some cases the tumors can be debilitating or even lead to death. Tumors may form in the brain or spinal cord, or on the optic and auditory nerves, where they impair hearing and vision.

But no matter what form the disease takes, its victims live with the fear that their condition will suddenly deteriorate. Many undergo surgery to remove tumors that interfere with normal activities, but run a risk that tumors not completely removed will grow back and multiply. Some bone malformations are serious enough to warrant amputation.

Because so little is known about neurofibromatosis, it often is diagnosed late in life. When Leta Diffenderfer of Silver Spring developed tumors at age 7, her doctor didn't know what they were. The tumors multiplied when she was 17 and she sought the advice of a dermatologist. It was then she was diagnosed as having NF.

For Diffenderfer, the lapse in time between the manifestation of the disease and the diagnosis caused considerable psychological -- and perhaps medical -- complications. "If they had told me when I was younger, I might have a better attitude towards it," she says. "That's pretty tough to put on somebody when they're 17."

Now 19, Diffenderfer estimates she has about 100 tumors, several of which have been removed. Her doctor recommended she quit her job as a dental assistant because they feared her job-related exposure to radiation might aggravate the tumors. She now works at Suburban Hospital, and doesn't try to hide the purple and brown marks indicative of her condition. "I don't want to hide it," she says, "because you're only hurting yourself when you hide it."

No one else in Diffenderfer's family has the disease, but her parents often attend the foundation's bimonthly meetings with her. They're very supportive, she says, and besides, graphic slides are shown and "you need somebody to hold sometimes."

For 45-year-old Doreen Flood of Greenbelt, neurofibromatosis has been an unwelcome part of her life since childhood. It is only in recent years, however, that her condition has worsened and the tumors have spread to most parts of her body. She has had several bothersome tumors removed, (one from an eyelid and another from a foot). She says the surgery is painful and can take several hours.

"I'm very sensitive about my appearance," she says. "There are very beautiful women's clothes, but I wear my top button buttoned and alwarys long sleeves. I don't wear dresses anymore, just pants."

Despite multiple other medical problems, including cancer, which she says are unrelated to NF, Foodn manages to lead an active life as a volunteer at Prince George's Hospital. "I forget about my appearance an awful lot. Working around people, I just forget," she says. "But there are times when I wish I could just stay home and hide in a closet."

Because of her appearance, Floodn is sensitive to the problems of the handicapped. She says people -- especially children -- are not educated to respect the needs of the handicapped. "There have been times when people have literally run away from me," she says.

Depite her infirmities, she says, she has always had a good attitude about herself and the need for personal dignity. "I have a problem that makes me different from other people," she concludes, "but I think I'd be this way anyway."