Disseminated BCG disease with defective immune metabolism caused by protein kinase C-delta deficiency

Protein kinase C-delta encoded by gene PRKCD is a unique member of the protein kinase C family, expressed in all types of tissues, and functions as a key molecule in maintaining immune homeostasis.1 It plays regulatory roles in B-cell signaling, autoimmunity, growth, apoptosis, and differentiation of a variety of cell types.1-3 Since 2013, 17 patients from 10 families have been reported with autosomal recessive PRKCD deficiency, and they clinically presented with systemic lupus erythematosus, lupus-like skin disease, or lymphoproliferative syndrome.