Olympic swimmer and gold medalist Michael Phelps may not have Marfan syndrome but he certainly has people talking about it.

In recent weeks there have been conflicting media reports that his long arms, slender physique and increased flexibility are signs he has the incurable condition, but an excerpt from his autobiography assures his fans he is disease-free.

Marfan syndrome is a genetic disease where the body's connective tissue is defective.

Because connective tissue is present throughout the body, this condition can affect many systems, including the skeleton, eyes, heart and blood vessels, nervous systems, skin and lungs, the National Marfan Foundation said on its Web site.

In the book, “Michael Phelps: Beneath the Surface,” Phelps describes how he first got to be checked at Johns Hopkins University in Baltimore, Md.

My heart rate was accelerating and Bob suggested I see the doctor. Because I was very flexible and had long hands and feet, I had some early symptoms of Marfan syndrome, a disease that affects connective tissues and can be fatal if there is leakage to the vessels that lead to the heart. If you reach out your arms and form a T and your wingspan is longer than your height, you can be at risk. In my case, those measurements have always been very close. I didn't know at the time why the doctor decided to look into this. My mom and Bob didn't want me to freak out, so they told me it was simply a good idea for young athletes to have an EKG test in order to look at the heart.

Fortunately everything was, and still is, okay. I have been tested once a year ever since at John's Hopkins under the direction of Dr. Peter Roe, and the tissues are strong, the aortic route is clear and my heart is in good shape - as long as my Baltimore Ravens are winning."

Dr. Reed Pyeritz, chief of the medical division of genetics at the University of Pennsylvania, said Phelps’ features certainly fit the criteria of a Marfan patient – but it could also fit anyone in the general population.

“So I would never dissuade anybody, a physician in particular, from suspecting Marfan syndrome,” Pyeritz said. “But, if that’s all there was, the likelihood would be relatively low.”

Other characteristics of Marfan patients include:

— protruding or concave sternum

— curvature of the spine

— dislocation of one or both eye lenses

— stretch marks, even without weight gain

— arching of the roof of the mouth, which may cause crowding of teeth

— enlargement of the aorta

— restrictive lung disease

Marfan syndrome may present itself in many different ways, according to the Foundation's Web site: Some patients are mildly affected and have only a few of these characteristics, while others are severely affected.

“The enlargement of the aorta can be present before birth or during childhood,” Pyeritz said. “But, in an adult male, if he had Marfan syndrome, it would be present. And, if they were looking for the disease, they would have detected the enlarged aorta already. I’m sure (Michael Phelps) had an echocardiogram already, and then he probably wouldn’t be swimming since physical activity is restricted.”

There are 200,000 people in the United States who have the disease or a related connective tissue disorder, said Eileen Masciale, director of communication for the National Marfan Foundation, which is located in Port Washington, N.Y.

Of those people, 50,000 to 60,000 have Marfan syndrome, she said, and about half of them are undiagnosed.

Marfan patients can live well into their 70s with proper treatment, which is why it is so important to be checked out, Masciale said.

In 1986, Olympic volleyball player Flo Hyman died of complications from Marfan syndrome. It is suspected that John Larson, writer of the Broadway musical "Rent," who died of an aortic aneurysm, also had the disease.

“Hyman had been checked countless times for college, for the Olympics, and no one suspected Marfan syndrome,” Pyeritz said.

However, soon after her death, an article ran in Sports Illustrated about the disease and a number of people with Marfan characteristics rushed to their doctors.

Pyeritz said he saw an increased number of patients that year.

“We wound up diagnosing a number of people,” he said. “There is great value in publicizing the features. The vast majority won’t have it based on flexible joints or long arms, but there will be a few who do have it and we will be able to save their lives.”