[Serratia osteomyelitis and chronic granulomatous disease]

Area of Science:

• Immunology
• Genetics
• Pediatrics

Background:

• Chronic Granulomatous Disease (CGD) is a primary immunodeficiency.
• X-linked CGD, accounting for over two-thirds of cases, results from CYBB gene mutations affecting NADPH oxidase.
• Recurrent infections characterize CGD, often involving bacteria, fungi, and mycobacteria.

Observation:

• A case report of a three-month-old infant with metacarpic osteomyelitis caused by Serratia marcescens.
• The patient exhibited an abnormal neutrophil respiratory burst and absent gp91-phox expression.
• A pathogenic mutation in the CYBB gene (c.252 G>A, p.Ala84Ala) affecting splicing was identified in the patient and a sibling.

Findings:

• Confirmed diagnosis of X-linked CGD due to a novel splicing mutation in the CYBB gene.
• Demonstrated absence of gp91-phox protein and impaired neutrophil function.
• Successful management with prophylactic antibiotics and antifungals.

Implications:

• Highlights the importance of considering CGD in infants with severe or unusual infections.
• Underscores the role of genetic testing in diagnosing primary immunodeficiencies.
• Emphasizes the effectiveness of early diagnosis and prophylactic treatment in managing CGD complications.