Sophie Nguyen recalls the day two years ago when she couldn’t run a mile in gym class without falling down. “I was pretty fit and used to be one of the fastest runners in the class,” says Sophie, now 14. “But I couldn’t even keep up with the kids who were walking, that’s how tired I was.”
Not surprisingly, she began to dread gym class. Her mother, Kathy Nguyen, initially assumed the issue was anxiety. But as the falls continued, Sophie’s twin sister, Andrea, always an outspoken advocate for her sister, told their mother she didn’t think anxiety was the culprit. Sophie often fell when it was just the two of them, like on Saturdays when they walked to their Chinese class. Plus, there were other signs that something was amiss; for instance, Sophie’s eyelids were drooping.
When the girls’ pediatrician later diagnosed Sophie with mononucleosis, the entire family was relieved. “We were high-fiving because at least mono wasn’t permanent,” says Kathy.
But as Sophie continued to fall and her fatigue worsened, her doctor referred her to a neuromuscular specialist. Bloodwork revealed high levels of autoantibodies interfering with her muscle function.
The diagnosis: myasthenia gravis (MG), a rare autoantibody disease in which the immune system mistakenly makes antibodies (e.g., anti-acetylcholine receptor, anti-muscle-specific tyrosine kinase and low-density lipoprotein receptor-related protein 4), which target proteins at the neuromuscular junction and can block or disrupt normal signaling from nerves to muscles. As a result, muscle contraction is impaired or prevented.
“Normally, whether we’re doing something involuntary, like swallowing or blinking, or something voluntary, like walking or running, the communication between the nerves and muscles is lightning-fast,” says Sindhu Ramchandren, M.D., Executive Medical Director, Neuroscience, Johnson & Johnson Innovative Medicine. “The nerve sends a signal to the muscles, and the muscles do their job. But in myasthenia gravis, autoantibodies disrupt this communication, making even everyday activities difficult.”
A rare disorder
Sophie lived with her symptoms for six months before she was finally diagnosed with MG—a delay common among MG patients. The disease is rare, especially in children; it impacts an estimated 700,000 people worldwide and approximately 10 to 15% of new cases of MG are diagnosed in pediatric patients 12 to 17 years of age. Among juvenile myasthenia gravis (JMG) patients, girls are affected more often than boys, with more than 65% of pediatric MG cases in the U.S. diagnosed in girls.
MG looks different in every individual, says Dr. Ramchandren. “Patients call it a ‘snowflake disease,’ meaning no two cases are exactly alike. Many MG patients experience at least one myasthenic crisis, which is a severe event characterized by breathing issues that lead to hospitalization, while others have less severe symptoms all their lives. Still others get worse over time either because of the side effects from medications, or from the disease itself.”
For Kathy, her daughter’s diagnosis was like an explosion. She began reading books on autoimmune disorders, joining MG Facebook groups and going down what she says was a rabbit hole of alternative therapies.
For her part, Sophie felt relieved by the diagnosis—at least at first. “I was excused from gym so I could sit on the sidelines and read a book, which was fantastic,” she says. “My parents also started driving me to my Chinese program on Saturdays, which made my life easier.” Arguably most importantly, she felt validated. “Finally,” she says, “it was clear to everyone that I wasn’t making the whole thing up.”
Seeking treatment for an incurable disease
Sophie’s treatment included a prescription to slow the breakdown of acetylcholine in her body. The medication helped, but the benefits would wear off after a few hours. She was also prescribed a number of other treatments, all meant to tamp down her immune system, the standard therapy for people with MG. “I knew immunosuppressants put her at risk of getting sick, and that steroids specifically could affect her growth over the long term, so I was very concerned,” says Kathy.
Everything was harder for me. When I tried to brush my hair or my teeth, my arms would get tired—even rolling over in bed was difficult.
As Sophie lived with the side effects from multiple treatments—including intense headaches that sometimes lasted three days at a time—her symptoms only worsened. “Everything was harder for me,” she says. “When I tried to brush my hair or my teeth, my arms would get tired—even rolling over in bed was difficult.”
Her family tried to pitch in by bringing things to her and carrying her upstairs, but it was hard being so dependent. “I had to ask for help with every little thing, even putting on a shower cap,” says Sophie. “It turns out everything you do needs a muscle.” In the summer of 2024, Sophie landed in the hospital.
Extended hospital stays are fairly common for children with MG: 30% percent of patients with MG are hospitalized during the first year of diagnosis, according to a recent study in the journal Neurology. “And 46 percent of pediatric patients with myasthenia gravis have at least one stay in the ICU,” adds Dr. Ramchandren.
A family rallies
For Sophie, family support and hospital visits made life with MG more tolerable. “My sister was always supportive,” she says. “At school, she carried my backpack. And when I was in the hospital, she stayed with me for hours at a time. My parents did, too. We were already close, but this made us all closer.”
Yet as with any health crisis, Sophie’s condition also created an enormous amount of stress for the family, particularly because there are few sources of support for people with JMG.
“Middle school is hard enough without having to cope with a rare condition that makes you feel isolated,” says Kathy. Thankfully, she was able to connect Sophie with a local support group through the Myasthenia Gravis Foundation of America. But her daughter was the only child present. “Trying to find her tribe has been difficult,” Kathy admits.
Then there was the added layer of navigating 8th grade in a wheelchair, which became a necessity. “Most people took my wheelchair in stride, but it made me uncomfortable,” says Sophie. “Kids would sometimes lean on the handles or wonder why I hadn’t needed a wheelchair the year before, or why I could walk sometimes—most people don’t realize that lots of people who use wheelchairs can walk sometimes.”
Kathy ultimately quit her job to devote more time to getting her daughter well, an option she knows isn’t available for every family. “Now, it’s much easier to be there for her and do all the things I need to do, whether that’s keeping track of her appointments or advocating for her at school,” says Kathy.
A turning point for MG patients
Despite the tremendous burden that adolescent MG can have on families, pediatric patients have long been underrepresented and underserved in neuromuscular disease research. The good news: There is currently a “golden age” of clinical trials for MG, and years of recent research have led to an improved treatment landscape for the disease that now includes targeted, longer-lasting options.
Some of these new medications have recently been approved for children as young as 12, and studies for children even younger are ongoing. “To have actual clinical trial data to show that a medication is safe and effective is priceless,” says Dr. Ramchandren.
A brighter future
Now a freshman in high school, Sophie has hit a milestone of her own. Her MG has stabilized and although she still has some symptoms—like dry eyes and occasional muscle fatigue—she’s reclaimed much of her previous life. “I’m able to walk upstairs again and sleep in my old bedroom with my sister,” she says. “I can brush my teeth and my hair without getting tired. And I won’t use my wheelchair in high school unless I really need it!”
Just as important, she’s eager to start this chapter in her life with a renewed sense of independence. “Having MG has helped me learn to advocate for myself, but it’s also taught me how to accept help from other people,” she says. “That has really been good for my mental and physical health and thanks to the support of my family, my doctors, my school and others, it’s all getting easier.”
