A homozygous CARD9 mutation in a Brazilian patient with deep dermatophytosis

Anete S Grumach1, Flavio de Queiroz-Telles, Mélanie Migaud

  • 1Outpatient Group of Recurrent Infections, Faculty of Medicine ABC, Santo Andre, SP, Brazil, asgrumach@gmail.com.

Insights

This study identifies a novel CARD9 mutation causing deep fungal infections in an immunocompetent patient. This finding expands the understanding of genetic predispositions to deep dermatophytosis.

Area of Science:

  • Immunology
  • Medical Mycology
  • Human Genetics

Background:

  • Deep dermatophytosis typically affects immunocompromised individuals.
  • Recent research links CARD9 (caspase recruitment domain-containing protein 9) deficiency to deep dermatophytosis in previously
  • immunocompetent" patients.

Observation:

  • A 24-year-old Brazilian male presented with persistent oral candidiasis from age 3.
  • He developed ulcerative, painful skin lesions at age 11, initially on the face and spreading to the trunk.
  • Trichophyton mentagrophytes was isolated from lesions, and antifungal treatments were ineffective.

Findings:

  • A novel homozygous CARD9 mutation (R101L) was identified, impairing neutrophil fungal killing.
  • The patient's family members showed varying carrier statuses for the mutation.
  • This is the first reported case of CARD9 deficiency in Latin America.

Implications:

  • Highlights CARD9 deficiency as a cause of deep dermatophytosis in immunocompetent individuals.
  • Expands the genetic and geographic understanding of CARD9-related immunodeficiency.
  • Suggests genetic screening for CARD9 mutations in unexplained deep fungal infections.

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