Case report: Novel CYBB missense mutation causing X-linked chronic granulomatous disease in a boy with recurrent pneumonia and testicular abscesses misdiagnosed as tuberculosis

Weiqi JiangPing RenTian Tian^*

• Xi'an International Medical Center Hospital, Xi'an, China

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by mutations in genes encoding the phagocyte NADPH oxidase complex, leading to recurrent bacterial and fungal infections.We describe a 2-year-old boy who developed severe infections beginning at 12 months of age, including necrotizing pneumonia and Staphylococcus aureus cervical lymphadenitis.He later presented with fungal pneumonia and epididymo-orchitis, followed by recurrent testicular abscesses that were initially treated as tuberculosis. Culture of excised tissue grew Burkholderia gladioli, and the lesions improved with intravenous meropenem. Whole-exome sequencing identified a novel hemizygous CYBB missense mutation, confirming X-linked CGD. Prophylaxis with trimethoprim– sulfamethoxazole and itraconazole has since prevented further severe infections. This case expands the CYBB mutational spectrum and underscores the need to consider CGD in children with recurrent catalase-positive infections or tuberculosis-like presentations, while highlighting the role of early molecular diagnosis in guiding prophylaxis, targeted therapy, and timely evaluation for curative options.