First Case of Deficiency of Adenosine Deaminase 2 (DADA2) in Oman With a Novel Mutation: A Case Report.

Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive disorder that results from biallelic loss-of-function mutations in the ADA2 gene. It is characterized by a spectrum of clinical features, predominantly vasculitis, autoinflammation, dysregulated immune function, and hematologic abnormalities, making it a challenging condition to diagnose. This case report presents the first documented case of DADA2 in Oman, highlighting a novel mutation in the ADA2 gene. It provides insights into the diagnostic process, therapeutic strategies, systemic evaluations, and family-focused management, contributing to the growing understanding of this rare disorder. This is a case of an 18-month-old male toddler who presented with persistent bi-cytopenia and a history of febrile seizures. Genetic testing revealed a novel homozygous pathogenic variant in the ADA2 gene. The patient was managed with infliximab infusions and regular follow-up. This report enhances the understanding of DADA2. The identification of a novel mutation in this case further highlights the growing insight into the pathogenesis of DADA2 and its clinical implications. Effective management requires genetic testing, systemic evaluation, and targeted therapy. Genetic counseling and family screening are crucial for early intervention and disease prevention. Further research is needed to improve diagnostics, treatments, and patient outcomes.