Fatal CTLA‐4 heterozygosity with autoimmunity and recurrent infections: a de novo mutation

Primary immunodeficiency disorders are rarely diagnosed in adults but must be considered in the differential diagnosis of combined recurrent infections and autoimmune disease. We describe a patient with CTLA‐4 haploinsufficiency and an abnormal regulatory T‐cell phenotype. Unusually, infections were more severe than autoimmunity, illustrating therapeutic challenges in disease course.