Double-hit RAG2 mutation presenting with hyper-immunoglobulin E and preserved T cells diagnostic challenge: a case report

This case underscores the diagnostic and therapeutic challenges in managing Omenn Syndrome, particularly in settings where routine newborn screening for severe combined immunodeficiency is not available. Early recognition and genetic diagnosis are vital to initiate life-saving interventions such as hematopoietic stem cell transplantation. Increased awareness among clinicians regarding atypical presentations of primary immunodeficiency can lead to earlier referrals, improved outcomes, and reduction in diagnostic delays.