TYK2 and hyper-IgE syndrome: The hyper-IgE syndromes have four distinct genetic causes including mutations in signal transducer and activator of transcription 3 (STAT3), dedicator of cytokinesis 8 (DOCK8), tyrosine kinase2 (TYK2) and phosphoglucomutase 3 (PGM3) (1, 34).