Case of Omenn Syndrome with a Novel RAG2 Missense Mutation

Omenn syndrome is one of rare severe immunodeficiency.It is characterized by the presence of a substantial number of oligoclonal, activated T cells, and the lack of B lymphocytes.Patients with Omenn syndrome usually die from opportunistic infections early in life.The cause of Omenn syndrome is mutations of the recombination activating genes (RAG1 or RAG2).Herein, we report a newborn Japanese case of Omenn syndrome with a novel RAG2 missense mutation.Although it is rare, dermatologists should be aware of Omenn syndrome as a cause of erythroderma in early infancy.