Treatment Brings Hope to Children Facing Spinal Muscular Atrophy, a Disabling, Often Fatal Disease

There is new hope for young patients who are diagnosed with a severely debilitating and often fatal genetic disease called spinal muscular atrophy, or SMA.

SMA affects the motor nerve cells in the spinal cord, taking away the ability to use muscles. This can impair walking, swallowing and even breathing.

Shane and Jennifer Lee, from Louisburg, North Carolina, are all too familiar with the disease. Of their five children, three were diagnosed with SMA: Jocelyn, Nathan and Kirra.

“Our journey started in 2007 with our first daughter, Jocelyn,” Mr. Lee says. “She was diagnosed with SMA type 1. She passed away from the disease at 4½ years old.”

The Lees’ son, Nathan, is now 6 years old and is wheelchair-bound, and he relies on a ventilator to breathe. But for Kirra, now 2 years old, a new medication has made all the difference.

What Is SMA?

SMA affects about 1 in 11,000 babies. “It’s relatively prevalent,” says UNC Children’s Hospital pediatric neurologist Zheng (Jane) Fan, MD. “It’s the second most common recessive disease that causes fatality in kids.”

“Children that inherit this disease start showing symptoms as early as the first few days of life, and over the course of time they lose muscle strength,” adds Yael Shiloh-Malawsky, MD, a UNC Children’s pediatric neurologist.

Children with SMA “are bright. They are very smart,” Dr. Fan says. But they are unable to move. “It is a very severe disease.”

There are several types of SMA. Without intervention, the most severe cases, called SMA type 1, typically result in death in the first few years of life. However, there is a new medicine that could change that. Drs. Fan and Shiloh-Malawsky have been treating Nathan and Kirra with a drug called Spinraza.

The Hope of Spinraza for SMA

“Spinraza is not a chemical. It’s not a protein. It’s DNA pieces with very specific sequences,” Dr. Fan says. “This medicine works. It’s lifesaving.”

SMA is caused when there’s a problem with both copies of the survival motor neuron 1 (SMN1) gene, which results in a deficiency of the survival motor neuron (SMN) protein. This protein is essential for the survival of the nerve cells that control muscles. In patients with SMA, a low level of SMN protein results in loss of muscle function. Spinraza prompts the body to produce the SMN protein so muscle strength can be maintained.

Kirra was diagnosed in utero with SMA, and the Lees reached out to UNC for help. At the time, Spinraza was still waiting for final FDA approval.

The Lees were excited by the drug’s potential, and then, “by the grace of God, three months before Kirra was born, the FDA approved Spinraza,” Mr. Lee says.

Nathan went years without treatment and still faces significant disabilities, but he has seen improvement with Spinraza.

“He was able to stop further progression,” Dr. Fan says. “He was able to regain some finger movement after the treatment and ankle movement, but the amazing thing is he was able to gain weight.” Nathan was at a critically low weight before treatment.

Kirra’s results have been especially remarkable. She was given Spinraza at just 11 days old.

“Clearly we treated her before the weakness began,” Dr. Fan says. Today, “she is a normal baby. She walked at the age of 11 months and she was running at the age of 15 months, and this is absolutely amazing.”

Kirra hasn’t shown any symptoms of SMA and has met every typical physical milestone. The abilities of babies like Kirra “underline the importance of newborn screening,” Dr. Fan adds. “Identify the disease earlier and treat them earlier.”

A Miracle Treatment for SMA Families

The Lees are stunned at Kirra’s development.

“Her middle name is Faith, being how she got here, because we would have never gotten here without our faith,” Mr. Lee says. “Kirra means ‘woman of light.’”

Spinraza has changed the course of SMA, Dr. Shiloh-Malawsky says.

“If treated early before symptoms start, most of these patients can have normal milestones, normal development. If treated later after symptoms develop, most patients will stop having deterioration of their condition and may even gain some strength,” she says.

Children need four doses of the drug in the first two months and then one maintenance dose every four months after that. Dr. Fan says insurance covered the cost for the Lee family.

“This has been amazing,” Dr. Fan says. “Historically, if you think about any genetic disease, we often are only able to treat the symptoms rather than correct the disease.”

To extend hope to more families, Drs. Fan and Shiloh-Malawsky want to see more genetic screening for SMA done on newborns. Then they can treat those who are diagnosed earlier and hopefully see more results like Kirra’s. North Carolina has a pilot study to do free newborn screenings called Early Check. UNC geneticist Cynthia Powell, MD, is a leader of the study, funded by the National Institutes of Health and led by the nonprofit RTI International.

“There’s a lot of hope, but there’s a lot of work to be done,” Dr. Shiloh-Malawsky says. “As a child neurologist, this is the most exciting event that’s happened in our field in decades, if not more.”

The Lees are proof of the power of screening and treatment; both Nathan and Kirra continue to do well.

“We’re excited about the future and what this miracle medicine is going to do for countless families,” Mr. Lee says. “It’s awesome to be able to share that there is hope.”

Learn more about UNC Children’s pediatric neurology care.