PIK3CD and immunodeficiency disease: Introduction: APDS (PASLI disease) (p110d-Activating mutation causing Senescent T cells, Lymphadenopathy, Immunodeficiency) is a primary immunodeficiency due to heterozygous GOF mutations in PI3Kδ catalytic p110δ or PIK3R1 genes causing APDS1 and APDS2 respectively.Digital vasculitis with C1q deficiency is reported in APDS2.Vasculitis not been reported in APDS1.