Severe Early-Onset Combined Immunodeficiency due to Heterozygous Gain-of-Function Mutations in STAT1
- 959 Downloads
Loss and gain-of-function (GOF) mutations in human signal transducer and activator of transcription 1 (STAT1) lead to distinct phenotypes. Although recurrent infections are common to both types of STAT1 mutations, GOF mutations are distinguished by chronic mucocutaneous candidiasis and autoimmunity. However, the clinical spectra of STAT1 GOF mutations continue to expand. We here describe two patients with STAT1 GOF mutations presenting early in life with combined immunodeficiency (CID).
Clinical data and laboratory findings including immunophenotyping, level of interferon (IFN)-γ/IL-17+ T cells, interferon-induced STAT1 phosphorylation, and JAK inhibitor assays were evaluated. Sequencing of STAT1 gene was performed by Sanger sequencer.
Patient 1 (P1) had persistent oral candidiasis and cytomegalovirus (CMV) infection since 2 months of age and later developed cavitary lung lesions due to Mycobacterium tuberculosis. Patient 2 (P2) presented with oral candidiasis and recurrent pneumonia at 4 months of age and subsequently developed CMV pneumonitis. Both patients suffered heterozygous missense mutations in STAT1, leading to deleterious amino acid substitutions in the DNA binding domain (P1: c.1154C > T; p.T385M; P2. c.971G > T; p.C324F). Circulating CD4+ T cells of both patients exhibited increased interferon-γ and decreased IL-17 expression as compared to controls. They also exhibited increased IFN-β and -γ-induced STAT1 phosphorylation that was reversed upon treatment with the JAK kinase inhibitor ruxolitinib.
STAT1 GOF mutations may present early in life with CID, consistent with the clinical heterogeneity of the disease. JAK kinase inhibitors may potentially be useful in some patients as adjunct therapy pending definitive treatment with bone marrow transplantation.
KeywordsSTAT1 gain-of-function mutation mucocutaneous candidiasis combined immunodeficiency autoimmunity ruxolitinib
This manuscript is dedicated to the memory of Professor Dr. Işıl Berat Barlan (1958–2015). This work was supported by the National Institutes of Health (5R01AI065617), to T.A.C.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- 10.Sampaio EP, Hsu AP, Pechacek J, Bax HI, Dias DL, Paulson ML, et al. Signal transducer and activator of transcription 1 (STAT1) gain-of-function mutations and disseminated coccidioidomycosis and histoplasmosis. J Allergy Clin Immunol. 2013;131(6):1624–34. Pubmed Central PMCID: 3746066.CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Soltesz B, Toth B, Shabashova N, Bondarenko A, Okada S, Cypowyj S, et al. New and recurrent gain-of-function STAT1 mutations in patients with chronic mucocutaneous candidiasis from Eastern and Central Europe. J Med Genet. 2013;50(9):567–78. Pubmed Central PMCID: 3756505.CrossRefPubMedPubMedCentralGoogle Scholar
- 13.Higgins E, Al Shehri T, McAleer MA, Conlon N, Feighery C, Lilic D, et al. Use of ruxolitinib to successfully treat chronic mucocutaneous candidiasis caused by gain-of-function signal transducer and activator of transcription 1 (STAT1) mutation. J Allergy Clin Immunol. 2015;135(2):551–3.CrossRefPubMedGoogle Scholar
- 15.Uzel G, Sampaio EP, Lawrence MG, Hsu AP, Hackett M, Dorsey MJ, et al. Dominant gain-of-function STAT1 mutations in FOXP3 wild-type immune dysregulation-polyendocrinopathy-enteropathy-X-linked-like syndrome. J Allergy Clin Immunol. 2013;131(6):1611–23. Pubmed Central PMCID: 3672257.CrossRefPubMedPubMedCentralGoogle Scholar
- 16.Sobh A, Chou J, Schneider L, Geha RS, Massaad MJ. Chronic mucocutaneous candidiasis associated with an SH2 domain gain-of-function mutation that enhances STAT1 phosphorylation. J Allergy Clin Immunol 2016Google Scholar
- 18.Toubiana J, Okada S, Hiller J, Oleastro M, Lagos Gomez M, Aldave Becerra JC, et al. Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype: an international survey of 274 patients from 167 kindreds. Blood 2016Google Scholar