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Disease in Disguise


By Michelle Brubaker   |   December 19, 2016

For Indira Iyer, the past year has been a nightmare. Her 18-year-old son has been living with a rare disease. His only chance of survival was the heart transplant he recently underwent.

Suraj Iyer

Suraj Iyer recently underwent a heart transplant to treat Danon disease. His skin cells are now being used to help identify a less invasive treatment.

“I wish there would have been other treatment options available, but there wasn’t,” said Iyer.

Iyer’s son, Suraj, was diagnosed with Danon disease when he was 7 years old. The number of patients with Danon disease in the United States is estimated to be less than 500. In patients with Danon disease, the basic biological process of removing and recycling dysfunctional cellular machinery doesn’t work properly. One consequence is a weakening of heart and skeletal muscles and disruption to cognitive function. The condition is more common in males and symptoms begin in childhood or adolescence.

Iyer says Suraj was a very athletic young child so she knew something was wrong when he began “huffing and puffing” at Little League practice.

“It was a maternal instinct,” said Iyer.

Eric Adler, MD, cardiologist at UC San Diego Health and associate professor of medicine at UC San Diego School of Medicine, is one of the few researchers in the nation studying Danon disease.

“In many cases, the condition is inherited by a parent, typically the mother,” said Adler. “We believe Danon disease is more common than we think, but it is often misdiagnosed and treated as heart failure.”

Danon cells

A. Healthy skin cells; B. Danon disease cells

Diseased heart muscle can lead to an enlarged heart. Alder says patients diagnosed with Danon disease have hearts that are two to three times larger than a normal heart and usually present with symptoms similar to heart failure, such as shortness of breath, fatigue and fluid gain.

The Iyer family has a history of the disease, but Indira has never been officially diagnosed. On average, males with Danon disease survive only to age 19 without a heart transplant.

“We are currently treating all heart failure the same, with a transplant, but this isn’t practical with more than 3,000 people in the United States currently on the wait list for a heart,” said Adler. “We need to find new therapies to address and treat Danon disease.”

Iyer says she has committed the last 11 years to worldwide research, ultimately leading her to Alder, who received a $2 million grant from the California Institute for Regenerative Medicine (CIRM) to study the disease at UC San Diego Health. He and his team are now turning patient skin cells into beating heart cells in a lab.

“By using the patient’s own skin cells to create a heart model, we can accurately study the disease in a very personal way,” said Adler. “We believe we can find a potential treatment therapy other than a heart transplant in the next five years.”

Kim Marincik and her sons were the first in the nation to be diagnosed with Danon disease in 2005.

Suraj’s skin cells are part of Adler’s research. The Iyer family, who lives in Pennsylvania, has traveled to San Diego to visit Adler’s lab. “We are thrilled to know our son’s skin cells are contributing to science and a potential break for all families suffering from this debilitating disease,” Iyer said.

Kim Marincik and her family were the first in the nation to be diagnosed with Danon disease. Both Marincik and her two sons, Liam (age 15) and Mason (age 11), were diagnosed in 2005.

“I just underwent my eleventh cardiac procedure and my oldest son just recently experienced his first. Both my boys get around now using scooters due to their muscle deterioration, and my youngest has significant development delay,” said Marincik, who is not a UC San Diego Health patient or part of the study. “Dr. Adler’s research is so important for the future of Danon disease. We hope his work will raise awareness and educate physicians so more testing can be conducted and patients receive the right diagnosis sooner.”

Adler says that for most people, science seems foreign and hard to grasp, but his study is truly resonating with patients since it’s their own stem cells beating in a Petri dish.

Skin Cells Turned into Beating Heart Cells

Danon disease, a rare genetic disorder is often misdiagnosed as heart failure. The disease weakens the heart and skeletal muscles, and a transplant is currently the only treatment available. A UC San Diego researcher is turning skin cells into beating hearts cells to find a less invasive therapy.

“Rare diseases can be disheartening to patients since overall they do not get the support of more common diseases,” said Adler. “I want patients with Danon disease to know that someone is fighting for them and working to identify a cure.”

Suraj is doing well post-heart transplant and is already back in college, but Iyer says she wishes for a day when all children with this disease are treated and families are saved from the heartbreak that comes with the condition.

“If a new treatment was discovered, it could literally save our entire family,” said Iyer.

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