Born with an incurable genetic disease that relentlessly weakens his muscles, Landon Tercano still adores playing power soccer from his wheelchair, loves chess and gardening and is in an honors program at his elementary school, according to his mother, Michelle.
Recently, in fact, as he awaited his first-ever soccer tournament in Jacksonville, she says, he could barely contain his excitement. “He just loves the game. It’s his favorite thing to do.”
Like most kids, 10-year-old Landon has his down days. But, Michelle describes her only child as mostly optimistic, highly resilient and warmly supported by a “great group of friends” in his Kissimmee neighborhood, as he struggles with Duchenne muscular dystrophy.
“We’re very open with him,” about the disease, she says, the most common and most severe of the neuromuscular disorders, known as dystrophies. All of them have been linked to errors or mutations in a single gene.
So, Landon knows what to expect, putting up with endless physical therapy sessions and daylong visits to a battery of specialists every six months to slow Duchenne progression. He’s also aware, his mother says, of promising research, which eventually could edit out parts of the defective gene, or replace it altogether, to enable his body to make dystrophin, the critical protein missing or limited once the gene mutates.
Landon Tercano is in an honors program at his elementary school. Photo by the Tercano family.
Dystrophin normally protects muscles as they flex and contract. Low levels of the protein, however, causes muscle deterioration, leaving behind scar tissue and life-threatening vulnerabilities, especially in the heart—one of the body’s strongest muscles.
By being as open as they are about Landon’s illness, it’s clear Michelle and Gil Tercano won’t allow his disability to define him. “You do life differently,” she says, referring to the demands of raising a special needs child. “But, you figure it out, and you adapt.”
Physicians diagnosed Landon with Duchenne muscular dystrophy in 2017 when he was 3 years old. Constant earaches, later requiring tubes in his ears, led to a recommendation that he undergo blood testing and tissue biopsies. For over six months, he endured these tests, Michelle says, with a final test detecting high levels of creatine phosphokinase, or CPK. Too much of the CPK enzyme indicated possible injuries to his muscles and heart and the need for genetic testing.
The test’s results blindsided the young couple. Neither knew of any family member with Duchenne, an X-linked inheritable disease, which passes down almost always from mother to son—occurring in an estimated 1 out of 3,500-to-5,000 live male births. Nor had they noticed any of the developmental delays, which usually show up by age five: trouble sitting, standing or walking and language difficulties.
Doctors also told them at first that Landon might be in liver failure, as skeletal muscles sometimes leak other enzymes into the blood, similar to the dystrophin protein. Instead, the test confirmed a diagnosis of Duchenne muscular dystrophy and left the Tercanos facing numerous challenges they had yet to understand.
Soon after Landon’s diagnosis, Michelle says, she underwent her own genetic testing, learning that she carries the faulty dystrophin gene, as it’s known, on one of her two X chromosomes. Because she still has a good gene, essentially balancing out the bad, geneticists say, it lessens her own disease risk and explains, in part, why Duchenne so rarely occurs in females. But as a carrier, Michelle knows, having another child, if the child is male, holds a 50% likelihood the genetic flow will recur.
Devastated by the news and driven by a desire to do whatever they could to help their son, the Tercanos began reaching out to other families and researching their options. For medical care, they moved closer to Nemours Children’s Hospital in Orlando and they connected with CureDuchenne, a global nonprofit that has invested more than $22 million into research, which has led to additional follow-on funding of more than $3 billion from other investors and companies to advance these programs further. The organization’s co-founders, Debra and Paul Miller, who live in California, created CureDuchenne a year after the diagnosis of Duchenne in their son, Hawken, in 2002.
CureDuchenne has backed 49 research projects, so far, 18 of which have advanced to human clinical trials, according to CureDuchenne’s 2023 Impact Report. Not only does that include the first drug approved by the U.S. Food and Drug Administration for Duchenne in 2016, says Debra Miller, CureDuchenne chief executive officer and founder, it also includes the first gene therapy, for 4-and 5-year-olds—the typical age for diagnosis—winning the federal agency’s fast-track approval just last year.
In addition, other drugs, including one Landon now takes, recently gained FDA approval as an alternative to steroids, a longtime staple in treating Duchenne to improve muscle function and to reduce inflammation. Clinical trials found the newer drug lessens the undesirable side effects of steroids after prolonged use: growth-stunting, unwanted weight gain and steroid-induced osteoporosis, brittle-bone disease often seen in older individuals.
No such treatment choices existed when doctors told the Millers their then 5-yearold son had Duchenne, says Debra Miller. “We were told that nothing could be done and to just go home and love our son,” who was not expected to live past 18. Today, however, through the powerful push of patient advocacy and continuing research progress, average life expectancy has increased by 10 years, she and others say.
And Hawken, now 26, a graduate of the University of Southern California, appears to be doing well, writing newsletters, blogs and other marketing materials for CureDuchenne, the organization’s website, states.
Hawken Miller was diagnosed with Duchenne at age 5. He is now 26 and a graduate of the University of Southern California, and also writes materials for CureDuchenne. Photo by Cureduchenne
To ensure other successes, CureDuchenne actively supports genetic screening for the disease in newborns. As with other conditions on the recommended uniform screening panel that states adopt, earlier diagnoses holds the promise of earlier intervention and better prognoses. The lack of treatments for young children in the past served as a barrier to this goal, Debra Miller says, but with the recent approval of one gene therapy—and severals others in the pipeline in late-stage testing—that soon could change.
Ohio is the only state currently mandating and also implementing testing for the muscular dystrophy gene in newborns, she says, although others states have moved closer to requiring its inclusion, including Minnesota and New York, and many other states have expressed interest.
As for Michelle, she enthusiastically supports the idea of newborn screening. The lack of any “big indicators” in Landon’s case, she says, never allowed the family to prepare, or perhaps, scientists to prevent the error through genetic-editing techniques, now in their infancy.
Not that she’s complaining.
Landon’s ability to make her laugh and his irrepressible spirit comes easily through her daily routines with him. “He’s my best friend,” she says.