An international group of doctors, scientists and patients met in Toronto on Friday to try to solve the mystery of an incurable and hard-to-diagnose lung disease that attacks mainly young women.

The 30 delegates are looking at lymphangioleiomyomatosis, or LAM.

It's a progressive disease that sometimes kills a person in just a couple of years, and it's almost always a woman in her childbearing years.

"We don't know how long people live," said Dr. Elizabeth Petri Henske, a LAM specialist at Harvard Medical School who is attending the summit.

"Partly because it's so hard to diagnose that we guess that only the most severely affected women get diagnosed. Probably many women have it and don't know it."

Doctors don't know what causes LAM, and the only cure at this point is a complete lung transplant. A few experimental drugs are now being tried.

Symptoms include:

• Shortness of breath.
• Chest pain.
• Collapsed lung.
• Abdominal discomfort.
• Frequent coughing.

The disease, discovered in the 1930s, forms abnormal cells that attack the lungs, kidneys and lymph system by creating cysts and destroying healthy tissue. A patient's lungs can be so deprived of oxygen that the patient suffers respiratory failure.

Estrogen suspected

About 30,000 to 50,000 people have been diagnosed with pulmonary LAM disease worldwide, while about 250,000 have LAM as part of another disease known as tuberous sclerosis complex (TSC), a hereditary disorder.

About 100 people in Canada are known to have LAM, but it may be underdiagnosed because its often confused with asthma or emphysema. It can take years for a patient to find out she has it.

Henske said the fact that it's almost always young women who get it leads to speculation that hormones are involved.

"There's a big effort in my lab to find out if estrogen is contributing and that's what everyone suspects. I think in all of human disease … it has a stronger gender predisposition than breast cancer. It's very striking."

The one-day summit has pulled in researchers from different disciplines — people who study LAM, TSC and pulmonary destruction — to see if they can come up with some models to study because so little is known about the ailment's origins.

The biggest breakthrough came eight years ago when it was discovered that both LAM and TSC showed similarities in a mutation in one of two tumor suppressor genes.

A cure can't come fast enough for Catherine Lawrence of Toronto and Amy Farber of Cambridge, Mass.

They both have the disease and have formed organizations to raise awareness, raise money for research and organize these kinds of summits.

Lawrence, a former marathon runner, says she is short of breath at this point, and Farber's case has progressed to the point where her lungs are now full of holes.

Says Farber: "I know that time is ticking and so the urgency and the desire to raise the red flag and say, 'Now is the time to act,' is what drives me to mobilize the scientists, 24 hours a day, working across the world with patients."