Clinical, biochemical, and genetic characterization of Lebanese patients with chronic granulomatous disease due to NCF2 pathogenic variants.

Chronic Granulomatous Disease (CGD) is caused by mutations in the NADPH oxidase complex that impair the ability of phagocytes to eliminate injested pathogens. As a result, patients with CGD suffer from recurrent infections and chronic inflammation. We report the clinical, biochemical, and genetic basis of the disease in 17 CGD patients from Lebanon. Whole exome sequencing (WES) identified 2 distinct mutations in NCF2 resulting in the deletion of exons 3 and 5, accounting for 82 % of the cases that underwent WES. This high prevalence provided the rationale for a diagnostic strategy involving assessment of NADPH oxidase function, identification of the affected protein, and targeted gene sequencing. Using this approach, 3 additional CGD patients with simmilar deletions were identified, supporting the presence of a founder effect in the Lebanese population. This biochemical and tageted sequencing approach is rapid, reliable, and cost-effective, making it a particularly valuable diagnostic option for families who cannot afford WES.