How an NBA player's genetic heart disease led to advocacy for hypertrophic cardiomyopathy

A healthy athlete all his life, Jared Butler entered his college basketball physical exam as the last step before he could step on the court. But an unexpected diagnosis of a potentially lethal heart condition put him on the sidelines while he anxiously wondered if his basketball career was over.

"After a month of testing, we found out that I had hypertrophic cardiomyopathy," Butler told ABC News. "I had never heard the term before. I was worried what this would mean for my playing career -- and ultimately my life."

That was three years ago. Today, Butler is coming off a starring role in an NCAA championship run at Baylor University and playing as a rookie in the NBA for the Utah Jazz. He has been able to continue his career thanks to routine cardiac evaluation and support by his family, doctors and team.

Hypertrophic cardiomyopathy is this most common genetically inherited heart disease, estimated to affect between 1 in 200 and 1 in 500 people worldwide, according to a 2015 study published in the Journal of the American College of Cardiology. The condition causes the heart muscle to become too thick, which could lead to life-altering conditions such as arrhythmias, heart failure, stroke or death.

Dr. Steve Ommen, cardiologist and medical director of the Mayo Hypertrophic Cardiomyopathy Clinic in Rochester, Minnesota, said the disease is not gender-selective and has no ethnic or geographic hotspots.

"The disease can manifest at any time and at any age among family members carrying the mutation," said Dr. Seema Mital, pediatric cardiologist and head of cardiovascular research at The Hospital for Sick Children in Toronto. "Some may even go without any evidence of the disease throughout their lifetime."

Once someone, like Butler, is found to have the disease, immediate family members are tested for the genetic mutation. In Butler's case, his mother, Juanea, also tested positive for genetic markers of the disease. She will also be monitored regularly by a cardiologist.

"I found out that I am the culprit. I am the one who carries the gene" said Juanea. "I was really confused and in a state of shock. I grew up active as well and never had symptoms or noted to have heart problems."

Mother and son were symptom-free their whole lives. But Dr. Michael Ackerman, genetic cardiologist at the Mayo Clinic and Jared Butler's physician, said people and physicians should be aware of the most-concerning symptoms, including chest pain, fainting and shortness of breath.

The disease can be especially risky for professional athletes because it increases the risk of sudden cardiac death. But thanks to the medical field having a better understanding of this disease, not every athlete needs to give up their career.

"Every athlete [with hypertrophic cardiomyopathy] doesn't need to give up what they're doing," said Mital. "Having the disease means you are going to be followed medically to make sure we can prevent heart failure and death. In fact, we now know that patients with hypertrophic cardiomyopathy can live a long, healthy life without any complications."

Ackerman has treated over 700 athletes with genetic cardiac conditions, a majority of whom do not require extensive medical procedures.

"For Jared, we made a plan with him, his family and his team and reassess that plan frequently and alter it as needed," said Ackerman. "This is not the new and improved way, this is just the approved and best way."

Ommen added that "shared decision-making" between a doctor and patient is meant to educate patients about the potential risks and make a group decision that is best for them.

He's more concerned about the 85% of the patients -- assuming 1 in 500 Americans have the condition -- who are living undiagnosed. To raise awareness, Butler and his mom decided to launch a campaign, "Could it be HCM?" in conjunction with Bristol Myers Squibb.

Ackerman added the second aspect of the campaign is knowing your family history. Having that knowledge about the sudden death of a family member could be life saving information

"Young patients come to the doctor complaining of shortness of breath, or chest pressure, and they are mistakenly diagnosed with exercise-induced asthma," said Ommen. "Campaigns like 'Could it be HCM?' are trying to raise awareness that if a young person does come in with symptoms, think about hypertrophic cardiomyopathy as one of the potential causes."

There is no cure, but Mital said that there are medications and surgical techniques to help alleviate symptoms and a lot of research invested in finding treatments to slow progression of the disease is in the future.

"Finding out you have the condition is just the beginning. It has been a long journey, and it has changed my life," said Butler. "But I find myself lucky that I do not have symptoms and I can continue playing basketball."

Lily Nedda Dastmalchi, D.O., M.A., is a physician and cardiology fellow at Temple University Hospital and a contributor to the ABC News Medical Unit.