CALR and autoimmune disease: Indeed the forms of cSLE with an onset before the age of 5 are usually rare monogenic variants (such as cases resulting from mutations in the complement system genes), or classified as neonatal lupus erythematosus (autoimmune disease acquired in utero as a result of transplacental passage of maternal anti-Sjögren’s-syndrome-related antigen A (anti-SSA/Ro), anti-Sjögren’s-syndrome-related antigen B (anti-SSB/La), or anti-U1 ribonucleoprotein (anti-U1-RNP) antinuclear autoantibodies) (6).