Deficiency of DNAse-1 (DNASE1), a cytoplasmic endonuclease degrading dsDNA [56], and lysosomal DNAse-2 (DNASE2) deficiency were reported in early-onset SLE patients who may exhibit “atypical” clinical features, such as neonatal pancytopenia, polyarthritis and cholestasis [57▪▪,58]. The gene discussed is DNASE1; the disease is polyarticular arthritis.