ORAI1 Mutation in a Child with Primary Immunodeficiency-9

Primary immunodeficiency-9 is an autosomal recessive disorder due to defects in the ORAI1 gene. ORAI1 encodes for calcium release-activated calcium (CRAC) channels which are essential for antigen induced gene expression for T cell activation and proliferation via the NFAT-driven pathway and T cell migration and homing to lymph nodes. Lymphocyte development is preserved while immune function is dramatically impaired. Patients with ORAI1 mutation are also at a higher risk of developing autoimmunity, ectodermal dysplasia, and muscular hypotonia.