We introduced the Prkcd G510S mutation that we previously associated to a Mendelian cause of SLE in the mouse genome, by means of CRISPR-Cas9 gene editing. PrkcdG510S/G510S mice recapitulate the human phenotype, presenting with glomerulonephritis, splenomegaly, and various serum autoantibodies, including anti-nuclear, and had reduced lifespan. We demonstrate that this phenotype is linked to a B cell autonomous role of PRKCD in immune regulation. The penetrance of the lupus phenotype is 100% in this mouse model.