title: STK4 (MST1) deficiency in two siblings with autoimmune cytopenias: A novel mutation.
abstract: Combined immunodeficiencies (CIDs) are heterogeneous group of disorders characterized by abrogated/impaired T cell development and/or functions that resulted from diverse genetic defects. In addition to the susceptibility to infections with various microorganisms, the patients may have lymphoproliferation, autoimmunity, inflammation, allergy and malignancy. Recently, three groups have independently reported patients having mutations in STK4 gene that cause a novel autosomal recessive (AR) CID. We describe here two siblings with a novel STK4 mutation identified during the evaluation of a group of patients with features highly overlapping with those of DOCK-8 deficiency, a form of AR hyperimmunoglobulin E syndrome. The patients' clinical features include autoimmune cytopenias, viral skin (molluscum contagiosum and perioral herpetic infection) and bacterial infections, mild onychomycosis, mild atopic and seborrheic dermatitis, lymphopenia (particularly CD4 lymphopenia), and intermittent mild neutropenia. Determination of the underlying defect and reporting the patients are required for the description of the phenotypic spectrum of each immunodeficiency.
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: seviloskay@gmail.com.
authors.forename: Sevil Oskay
authors.initials: SO
authors.lastname: Halacli
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: dcagdas@gmail.com.
authors.forename: Deniz Cagdas
authors.initials: DC
authors.lastname: Ayvaz
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: cagmantan@gmail.com.
authors.forename: Cagman
authors.initials: C
authors.lastname: Sun-Tan
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: baranerman@gmail.com.
authors.forename: Baran
authors.initials: B
authors.lastname: Erman
authors.affiliation: Uludag University, Faculty of Arts and Sciences, Department of Molecular Biology and Genetics, 16059 Bursa, Turkey. Electronic address: elifuz@uludag.edu.tr.
authors.forename: Elif
authors.initials: E
authors.lastname: Uz
authors.affiliation: Hacettepe University Medical Faculty, Institute of Child Health, Laboratory of Metabolic Diseases, Sihhiye, 06100 Ankara, Turkey. Electronic address: dyucel@hacettepe.edu.tr.
authors.forename: Didem Yucel
authors.initials: DY
authors.lastname: Yilmaz
authors.affiliation: Hacettepe University Medical Faculty, Institute of Child Health, Laboratory of Metabolic Diseases, Sihhiye, 06100 Ankara, Turkey. Electronic address: rkozgul@hacettepe.edu.tr.
authors.forename: Koksal
authors.initials: K
authors.lastname: Ozgul
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: fetezcan@hacettepe.edu.tr.
authors.forename: İlhan
authors.initials: İ
authors.lastname: Tezcan
authors.affiliation: Hacettepe University, Institute of Child Health, Department of Pediatric Immunology, Sihhiye, 06100 Ankara, Turkey. Electronic address: sanaloz@gmail.com.
authors.forename: Ozden
authors.initials: O
authors.lastname: Sanal
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis / Q000235:genetics*; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D047908:Intracellular Signaling Peptides and Proteins; D007589:Job Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D008231:Lymphopenia / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D008297:Male; D009154:Mutation; D010375:Pedigree; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics*; D035781:Siblings; D000099317:Hippo Kinases
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; C095566:STK4 protein, human; D000099317:Hippo Kinases
keywords: Autoimmune cytopenia; Hyper IgE syndrome; STK4 deficiency; T cell deficiency