%0 Case Reports
%T Activated phosphoinositide 3-kinase delta syndrome misdiagnosed as anti-neutrophil cytoplasmic antibody-associated vasculitis: a case report.
%A Zhang X
%A Wang J
%A Zhu K
%A Jin Y
%A Fu H
%A Mao J
%J J Int Med Res
%V 49
%N 5
%D May 2021
%M 34039074
%F 1.573
%R 10.1177/03000605211013222
%X Activated phosphoinositide 3-kinase delta syndrome (APDS) is a combined inborn error of immunity mainly caused by PIK3CD mutations. We herein describe a 4-year-old Chinese boy who was admitted for recurrent pneumonia and persistent hematuria and exhibited multisystem involvement and anti-neutrophil cytoplasmic antibody (ANCA) positivity. He was initially diagnosed with ANCA-associated vasculitis. However, genetic testing revealed a c.1574A>G PIK3CD mutation, resulting in a diagnosis of APDS1.