Leo the Superhero

Patient Stories

Leo the Superhero


Leo was a happy and healthy child. He reached his developmental milestones, walking and babbling during his first year. However, after the age of two, things began to change. Leo became increasingly unsteady until he could no longer walk or run. His parents consulted a multitude of specialists—even traveling to Japan—but after many tests, there was still no diagnosis.

As his parents continued to look for answers, Leo’s motor and verbal skills rapidly deteriorated. By the time he started preschool, he was in a wheelchair, his speech was slurred and he had trouble swallowing food.

“His mom and I are always in awe of his determination and how he faces every adversity with a smile,” says Leo’s dad, Satoshi. “He’s always been our superhero! Leo cannot walk, talk or even eat on his own, even though he was able to do all of that just a few years back.”

Finding hope at the NRI

It wasn’t until Leo underwent in-depth genetic testing that he was diagnosed with a mutation of the IRF2BPL gene. While very little is known about this complex condition, Satoshi found the only place where experts discovered the importance of this gene variant: the Jan and Dan Duncan Neurological Research Institute (NRI) at Texas Children’s Hospital.

Using a multidisciplinary approach that combined comprehensive clinical tests, exome sequencing, and studies in fruit flies, these NRI researchers identified the variant in IRF2BPL gene that was responsible for Leo’s condition. This cutting-edge process is akin to finding a needle in a haystack because the human genome consists of 3 billion base pairs and most people have many genetic variants in their genome, not all of which are harmful or cause disease.

Eager to learn more about their son’s condition, the family visited the NRI and met with Drs. Hugo Bellen, Shinya Yamamoto, Michael Wangler and Huda Zoghbi. They were astonished to see how fruit flies with the same genetic mutation as Leo could be the key to finding a treatment for his condition!

Satoshi explains, “After years of trying to make sense of Leo’s condition, my wife and I were elated. We are at the cusp of yet another long journey to find a treatment for Leo and other children like him who have IRF2BPL variants. The huge difference this time around is that we’re not alone. We feel blessed to have the support of other families and talented teams of physicians and scientists who are as passionate as we are about finding a treatment for this disorder.”

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