Deep Dermatophytosis and Inherited CARD9 Deficiency

BackgroundDeep dermatophytosis is a severe and sometimes life-threatening fungal infection caused by dermatophytes. It is characterized by extensive dermal and subcutaneous tissue invasion and by frequent dissemination to the lymph nodes and, occasionally, the central nervous system. The condition is different from common superficial dermatophyte infection and has been reported in patients with no known immunodeficiency. Patients are mostly from North African, consanguineous, multiplex families, which strongly suggests a mendelian genetic cause. MethodsWe studied the clinical features of deep dermatophytosis in 17 patients with no known immunodeficiency from eight unrelated Tunisian, Algerian, and Moroccan families. Because CARD9 (caspase recruitment domain-containing protein 9) deficiency has been reported in an Iranian family with invasive fungal infections, we also sequenced CARD9 in the patients. ResultsFour patients died, at 28, 29, 37, and 39 years of age, with clinically active deep dermatophytosis. No other severe infections, fungal or otherwise, were reported in the surviving patients, who ranged in age from 37 to 75 years. The 15 Algerian and Tunisian patients, from seven unrelated families, had a homozygous Q289X CARD9 allele, due to a founder effect. The 2 Moroccan siblings were homozygous for the R101C CARD9 allele. Both alleles are rare deleterious variants. The familial segregation of these alleles was consistent with autosomal recessive inheritance and complete clinical penetrance. ConclusionsAll the patients with deep dermatophytosis had autosomal recessive CARD9 deficiency. Deep dermatophytosis appears to be an important clinical manifestation of CARD9 deficiency. (Funded by Agence Nationale pour la Recherche and others.) Dermatophyte infections are unusual but can cause serious invasive disease. In this report, autosomal recessive CARD9 deficiency indicated a potential genetic susceptibility to deep dermatophytosis, a severe invasive fungal infection. Deep dermatophytosis is a rare, invasive, sometimes life-threatening, fungal infection caused by dermatophytes.(1) These filamentous fungi are ubiquitous and usually cause benign infections that are limited to keratinized tissues and lead to onychomycosis, tinea corporis, tinea cruris, tinea pedis, or tinea capitis.(2) In deep dermatophytosis, dermatophytes invade the dermis and hypodermis and disseminate to the skin, hair, nails, lymph nodes, and brain.(3) Deep dermatophytosis has been reported in patients with the human immunodeficiency virus and patients who are receiving immunosuppressive therapy.(3) It was first described in 1959 in otherwise apparently healthy persons as dermatophytic disease.(1) Forty-five cases have been reported ...