A Second Chance for Simon: Living with NEMO Deficiency Syndrome

When Simon was born, there was no immediate sign that anything was wrong. But at just 11 days old, he was hospitalized with a high fever and fungal infection. Doctors called it a fluke, and his family hoped it would be a one-time scare.

But the warning signs kept coming. A bone infection from a simple scratch. A puzzling lack of response to vaccines. Unusual cone-shaped teeth that didn’t match typical growth patterns. His parents, Sandie and Dan, knew something was wrong—even if no one could name it yet.

Photo shared from GeneDx.com

That changed when Simon's care team turned to advanced genetic testing, and the results finally gave them the answer they'd been searching for: NEMO Deficiency Syndrome, a rare primary immunodeficiency caused by mutations in the IKBKG gene.

This condition severely compromises the body’s ability to fight infection. Children with NEMO experience recurrent bacterial and viral infections, especially in the lungs, skin, and gastrointestinal tract. There are only about 200 known cases worldwide, making diagnosis and treatment an urgent—and challenging—journey.

Simon's mom Sandie shared, “You want your kid to live a full life, but for so long, we didn’t know if that would be possible... we were so surprised when his doctors cleared him to go on that adventure... a simple pleasure of life that we weren’t sure he’d ever get to experience.”

The diagnosis changed everything. It helped Simon’s doctors adjust his medications, refer him to specialists at Texas Children’s Hospital and the NIH, and ultimately perform a successful bone marrow transplant—before irreversible organ damage could set in.

Today, Simon is thriving. He’s in kindergarten. He’s made friends. He went swimming in a lake for the first time—something his parents once feared might never be possible.

His story is a powerful reminder of the role early diagnosis, genetic testing, and specialized care play in the lives of children with primary immunodeficiencies. At the Yellow Bear Foundation, we stand with families like Simon’s—because no child should have to fight rare disease without answers, hope, or support.

Original story shared by GeneDx.