Recurrent subcutaneous abscesses and pneumonia in a toddler with a novel pathogenic variation in IL-17RA gene

Area of Science:

• Immunology
• Genetics

Background:

• Inborn errors of immunity (IEI) can manifest with recurrent infections, necessitating early diagnosis.
• Interleukin-17 receptor A (IL-17RA) pathway is crucial for host defense against fungal and bacterial pathogens.

Observation:

• A toddler presented with recurrent subcutaneous abscesses, otitis media, pneumonia, and failure to thrive.
• Diagnostic workup revealed neutrophilic leucocytosis, elevated inflammatory markers, and isolation of Klebsiella pneumoniae from blood culture.
• Genetic analysis identified a novel homozygous pathogenic variant in the IL-17RA gene.

Findings:

• The patient exhibited a novel homozygous pathogenic variant (c.2563G>A, p. Asp855Asn) in the IL-17RA gene.
• Dihydrorhodamine-123 assay was negative, and immunoglobulin profile showed elevated IgG.
• Treatment with intravenous colistin and fluconazole resulted in complete resolution of abscesses and clinical improvement.

Implications:

• IL-17RA deficiency should be considered in children with recurrent deep-seated abscesses, skin ulcerations, and pneumonia, especially after common IEIs are excluded.
• Identification of novel IL-17RA variants expands the genotypic spectrum of this IEI.
• Targeted antimicrobial and antifungal therapy can effectively manage IL-17RA deficiency, highlighting the importance of genetic diagnosis.