[Bacillus Calmette-Guérin infection and chronic granulomatous disease due to new pathogenic variants in the NCF2 gene in the Mayan ethnic group. Report of two cases.]

Introduction: Chronic granulomatous disease (CGD) is an inborn error of immunity, characterized by abnormal susceptibility to bacterial and fungal infections and a lack of systemic inflammatory regulation. Pathogenic variants in the CYBB gene are transmitted in an X-linked pattern of inheritance; while the pathogenic variants present in the EROS, NCF1, NCF2, NCF4, or CYBA genes are transmitted with an autosomal recessive inheritance pattern.

Objetives: To describe the clinical, immunological, and genetic characteristics of two patients with CGD and BCG infection.

Methods: In peripheral blood neutrophils, H₂O₂ production and the expression of NADPH oxidase subunits were measured. Detection of pathogenic variants was by Sanger sequencing of the NCF2 gene. The clinical information was extracted from the records by the treating physicians.

Results: We present two male infants from two unrelated families of Mayan ethnicity, with CGD and BCG vaccine infection. Three different pathogenic variants in the NCF2 gene were identified; on the one hand, c.304 C>T (p.Arg102*) has already been reported, on the other hand, c.1369 A>T (p.Lys457*) and c.979 G>T (p.Gly327*) not reported.

Conclusions: In patients with mycobacterial infection with BCG, we should suspect an inborn error of immunity, such as CGD. The diagnosis of CGD is made through the detection of a lack of radical oxygen species in neutrophils. The reported patients had pathogenic variants in the NCF2 gene, two of which have not been previously reported in the literature.