Severe pulmonary involvement and elevated interferon-stimulated genes expression in two siblings with a novel C1QB pathogenic variant

We report vasculitis and interstitial lung disease in two siblings with a novel C1QB pathogenic variant. Patients responded to rituximab + tacrolimus or baricitinib. This report broadens the genotypic and phenotypic landscape of C1Q deficiency and extends on the similarities with other type 1 interferonopathies.