Abstract
OBJECTIVE: To investigate the etiology of recurrent severe pneumonia and pleural effusion in a pediatric patient through pathogenic gene testing and bioinformatics analysis. METHODS: Clinical characteristics and laboratory findings were retrospectively reviewed. Peripheral blood samples were collected from the patient and both parents. Genomic DNA was extracted and subjected to trio whole-exome sequencing (WES) using high-throughput sequencing technology. Sanger sequencing was used to validate suspected pathogenic variants. RESULTS: Whole-exome sequencing revealed a homozygous variant c.427C>T (p.Q143*) in exon 6 of the CYBA gene, inherited from both parents. This variant has not been previously reported in the literature. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, c.427C>T(p.Q143*) was assessed as a likely pathogenic variant (PVS1_Strong+PM2_Supporting+PM3_Supporting). This variant is associated with autosomal recessive chronic granulomatous disease type 4(A22° CGD). CONCLUSION: This study identified a novel CYBA gene variant in a pediatric patient with recurrent severe pneumonia and pleural effusion, expanding the spectrum of pathogenic variants in this gene and providing evidence for clinical diagnosis and genetic counseling.