DEF6 deficiency, a mendelian susceptibility to EBV infection, lymphoma and autoimmunity.

By studying four siblings with a null homozygous mutation in DEF6, we show that DEF6 deficiency is a new inherited immune dysregulation disorder with variable expressivity from autoimmunity/inflammation to EBV-associated viremia/lymphoproliferation/lymphoma without extra-hematopoietic manifestations.