Prenatal Autoimmune Disease, Multisystem, Infantile Onset-like Phenotype and Proximal Renal Tubular Dysplasia Associated With STAT3 Mutation.

Activating heterozygous germline mutations in the signal transducer and activator of transcription 3 (STAT3) gene are associated with the rare autoimmune disorder autoimmune disease, multisystem, infantile onset (ADMIO). The phenotype of ADMIO is typified by hypogammaglobulinemia and onset of autoimmune phenomena during early childhood that include diabetes and autoimmune enteritis. This case report describes in utero onset of precocious lymphocyte maturation, autoimmune enteropathy-like inflammation, and proximal renal tubular dysplasia associated with a novel de novo heterozygous STAT3 mutation. The findings expand the phenotype associated with activating STAT3 mutations and suggest that the impact of the immunological abnormalities associated with ADMIO can begin prior to birth.