RAG2 and Omenn syndrome: Mutations in RAG1 or RAG2 can lead to a spectrum of disorders, ranging from typical B-T-severe combined immunodeficiency to Omenn's syndrome.<h4>Case presentation</h4>A two-month-old Saudi baby girl presented with fever, respiratory distress due to bronchiolitis, exfoliative erythroderma and a family history of childhood death within the first few months of life in two of her sisters who had had a similar clinical presentation to her own.