Genetic testing helps one family navigate a challenging diagnosis

A healthcare shortage complicates Marissa’s search for answers

The Martens family lives in rural southern Alberta outside the town of Lethbridge, where it’s always been more challenging to find specialized care. A healthcare shortage throughout the province made their search even harder.

Getting routine care was already tricky for the Martens. “The southern zone has been without doctors for the last 4 years, and patients have been without a family doctor for upwards of 8 years,” said Marissa.

Finding a healthcare provider who could help them unravel the mystery of what was happening to Meaghen would be even harder, but Marissa was undaunted.

She brought Meaghen to an audiologist, thinking maybe she’d lost her hearing. But her hearing was perfect. “At this point, we thought she was just choosing not to respond.”

Then she found Meaghen an appointment with a pediatric specialist who visits a clinic in their region once a month. He told her the nature of Meaghen’s symptoms and their sudden onset — ”Like somebody flipped a switch,” Marissa said — indicated she had level 3 autism, the most severe form of the condition.

The day after Meaghen received this diagnosis, that doctor retired. It took Marissa another six months to find another specialist to help them.

Meaghen was 2½ when she saw a pediatric specialist with autism expertise. Her new doctor recommended they try genetic testing, particularly for epilepsy. Marissa reasoned there might be other health implications they didn’t yet know, and a genetic test may reveal them.

“We figured we could be proactive, get it done and eliminate some of the problems we might face.” So, Meaghan’s doctor ordered an epilepsy gene panel.

Marissa appreciated how easy the test was on Meaghen. “It was non-invasive. They didn’t have to strap her down or take blood. There was a little discomfort from having a Q-tip in her mouth, and that was it.”

When the results returned a few weeks later, they told a story different from what Meaghen’s doctors had suspected.

A genetic test clarifies Meaghen’s diagnosis

Meaghen didn’t have autism. Her genetic test showed she had a rare variant in the RHOBTB2 gene that causes seizures, movement disorders and intellectual disability.⁵ Meaghen’s developmental regressions were due to having many small seizures — so small her caregivers couldn’t see them happening, but so constant they undermined her ability to walk, talk, feed herself and keep learning the basic skills of childhood.

RHOBTB2 syndrome was first described in 2018. In 2023, only 34 patients were identified,⁵ but talk among families who’ve connected through online support groups indicates there may be more.

“She’s not talking yet,” said Marissa, “but she’s making sounds. She can move her hands. She can see herself. She’s selective about who she interacts with, but not all kids with this disease even have that ability.”

Before Marissa had children, she’d done her own genetic test to find out if she had any risk of passing a disease-causing variant down to her kids. That test didn’t identify the genetic variant that Meaghen’s test later identified.

Meaghen’s RHOBTB2 variant was a “de novo missense change,”⁶ a genetic variant that happens spontaneously as an embryo develops. None of her family members have this gene variant.

Becoming advocates for Meaghen and her RHOBTB2 syndrome

Receiving a more precise diagnosis helped Meaghen’s doctors focus on treating her symptoms and recommending the proper tests and therapies. For example, Meaghen could benefit from an electroencephalogram (EEG), which measures electrical activity in the brain, and magnetic resonance imaging (MRI), which produces detailed images of the body’s internal structures.

“Meaghen needed better support,” Marissa said. “And quite frankly, so did I.”

At first, Marissa didn’t understand the basic support structures that Meaghen needed, like a steady routine.

Protecting Meaghen’s quality of life

This September, she started preschool. With the help of a teaching aid Marissa calls “an angel walking this earth,” Meaghen has blossomed. “She’s started to come out of her shell, play near others and even use items for their intended purposes,” Marissa says. “It’s phenomenal.”

Of the genetic test that revealed the actual cause of Meaghen’s condition, Marissa said, “The results gave us the insight we needed and helped us focus our concern on what was really happening with Meaghen. The news was painful, but it allowed us to adapt to that pain. It improved Meaghen’s quality of life, which should be the ultimate goal. We just want to make sure she has the best life possible.”

To explore genetic testing options that may be right for your, visit Invitae, now part of Labcorp. Learn More

To find more genetic testing patient stories from people like Meaghen, visit Invitae, now part of Labcorp. Learn More