Recurrent Enteritis and Intestinal Obstruction in a Patient with Chronic Mucocutaneous Candidiasis due to STAT1 Gain-of-Function Mutation.

We presented a case of chronic mucocutaneous candidiasis (CMC) due to STAT1 GOF mutation with recurrent enteritis and intestinal obstruction. A 33-year-old woman complained of recurrent oral erosion and finger (toe) nails damage for over 30 years. Candida albicans were cultured from the oral mucosa and nails. Sanger sequencing revealed a gain-of-function mutation in STAT1 (c.A1159 G, p.T387A). Since the age of 37, she developed recurrent enteritis and intestinal obstruction. Laboratory examinations revealed an increased pSTAT1 protein expression and a decreased proportion of Th17 cells in peripheral blood lymphocyte (PBMC), with a high expression of pSTAT1 and scarce expression of IL17A observed in intestinal immunohistochemistry. Intestinal obstruction had not previously been reported as the main clinical manifestation in STAT1 GOF patients. We speculated that the low levels of IL17A impaired the intestinal barrier, which might lead to gastrointestinal disorders in this patient. This case expanded the clinical phenotype of heterozygous STAT1 GOF patients.