DOCK8 deficiency

Purpose of review Previously described as an autosomal recessive form of hyper IgE syndrome, DOCK8 deficiency is now recognized as a combined immunodeficiency, with predominant dermatological manifestations. This review details overlap between DOCK8 deficiency, actin regulator actinopathies, and Tregopathies, and summarizes current treatment experience. Recent findings Dermatological infection and inflammation are predominant features of DOCK8 deficiency. Previous research demonstrated the importance of the actin defect in contributing to the severe and persistent viral infection that characterizes DOCK8 deficiency. More recent findings have demonstrated a reduction in number and function of regulatory T lymphocytes in the skin of patients with DOCK8 deficiency, which contributes to the severe inflammatory phenotype and may be controlled by treatment with dupilumab. The outcomes of haematopoietic stem cell transplantation are summarized. Summary DOCK8 deficiency is a severe inborn error of immunity with features of Tregopathies, actinopathies, and STAT3 signalling defects. Curative treatment with haematopoietic stem cell transplantation should be offered to these patients, and abolishes most of the symptoms, although allergic manifestations may persist.