Introduction: GoF mutations of STAT1 were initially associated with mucocutaneous candidiasis and manifestations of autoimmunity and inflammation. The initial approach is usually the treatment of infectious and non-infectious manifestations.
Presentation of the case: female patient, five years old, presents from the first year of life with extensive oral, nail, and cutaneous candidiasis not responsive to different topical and oral antifungal treatments. She does not present any other non-infectious, autoimmune, or inflammatory manifestation. No inbreeding, no family history of autoimmune, inflammatory, or mucocutaneous candidiasis. Immunoglobulin dosage and phenotyping of lymphocytes are normal. Genetic sequencing performed by the Veritas laboratory, by the Jeffrey Modell Foundation program, identified mutation in STAT1 (STAT1(NM_007315):c.1154C>T (p.Thr385Met), missense variant, heterozygous, classified as PATHOGENIC. Ruxolitinib has been indicated but has yet to be started.
Discussion: Mutations with STAT1 GoF do not always present early with autoimmunity or inflammation, and there is not always a good response with available treatments for Candida spp. Infection. Ruxolitinib has been used successfully.