Genetic sequencing revealed that Rafi had an extremely rare, often fatal disease — and the discovery was amazingly made before he had serious symptoms.

Small, flu-like symptoms quickly worsened for 13-year-old Joey, causing his organs to fail and his family to desperately search for help with his rare disease.

When Andrea, 10, began having vision problems, there's no way her family could have predicted the complex diagnostic journey they were about to embark upon.

In unlocking the key to Elijah’s mystery illness, CHOP doctors identified a new autoimmune disease and developed a customized plan to treat his disorder.

After receiving treatment for hemophagocytic lymphohistiocytosis (HLH) at Children’s Hospital of Philadelphia, Luca is on the road to recovery.