Deficiency of caspase recruitment domain-containing protein 9 (CARD9) is an autosomal recessive primary immunodeficiency disorder, which typically predisposes immunocompetent individuals to single fungal infections and multiple fungal infections are very rare. We study an otherwise healthy 48-year-old man, who had been admitted to our hospital diagnosed with deep dermatophytosis caused by Trichophyton rubrum for three times at 29, 33 and 48 years old, respectively. At the age of 39 years, he suffered from cutaneous mucormycosis due to Mucor irregularis. Moreover, he had a long history of superficial fungal diseases and occasional oral candidiasis. Whole-exome sequencing revealed two compound heterozygous splicing variants in CARD9 gene, c. 184 + 5 G > T and c. 951G > A, confirmed by Sanger sequencing. Patients with recurrent fungal infections especially invasive fungal infections in the absence of known immunodeficiencies should be tested for CARD9 mutations.
Keywords: CARD9 deficiency; Deep dermatophytosis; Mucormycosis; Superficial dermatophytosis.