Gain-of-function mutations in signal transducer and activator of transcription 1 ( STAT1 ): Chronic mucocutaneous candidiasis accompanied by enamel defects and delayed dental shedding

Immunophenotyping showed a low percentage of switched memory B cells (1.3%; normal range, 5% to 10%; see Table E3 in this article's Online Repository at www.jacionline.org). Because withdrawal of IVIG was associated with an increased incidence of pneumonia, treatment was optimized by restarting IVIG and initiating azithromycin (both for antibacterial prophylaxis and its anti-inflammatory actions) and fluconazole prophylaxis, as well as overnight tube feeding. [...]at the age of 18 years, hypothyroidism was diagnosed almost simultaneously with the initial reports on STAT1 coiled-coil domain gain-of-function mutations.3,4 A mutation in the DNA-binding domain of STAT1 was detected (c.1154C>T, p.T385M; Fig 2, A; for information on the analysis, see the Results section in this article's Online Repository at www.jacionline.org).