98%
921
2 minutes
20
We report a novel variant in associated with IKAROS haploinsufficiency in a patient with familial immune thrombocytopenia (ITP). IKAROS, encoded by the gene, is a hematopoietic zinc-finger transcription factor that can directly bind to DNA. We show that the identified variant (p.His195Arg) alters a completely conserved histidine residue required for the folding of the third zinc-finger of IKAROS protein, leading to a loss of characteristic immunofluorescence nuclear staining pattern. In our case, genetic testing was essential for the diagnosis of IKAROS haploinsufficiency, of which known presentations include infections, aberrant hematopoiesis, leukemia, and age-related decrease in humoral immunity. Our family study underscores that, after infections, ITP is the second most common clinical manifestation of IKAROS haploinsufficiency.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6491668 | PMC |
http://dx.doi.org/10.3389/fped.2019.00139 | DOI Listing |
Clin Immunol
May 2025
Department of Pediatrics, National Defense Medical College, Saitama, Japan. Electronic address:
IKAROS, encoded by IKZF1, is a crucial transcription factor regulating hematopoiesis and B cell development. While IKZF1 haploinsufficiency variants are associated with various immunological disorders, inflammatory bowel disease (IBD) has been rarely reported. We report a case of IKZF1 haploinsufficiency presenting with an atypical IBD phenotype and its response to filgotinib.
View Article and Find Full Text PDFClin Immunol
May 2025
Immunology Service, Department of Laboratory Medicine, NIH Clinical Center, NIH, Bethesda, MD, USA. Electronic address:
IKAROS, encoded by IKZF1, is a six zinc-finger (ZF) transcription factor integral to lymphocyte development and function. IKZF1 mutations affecting DNA-binding (ZF1-4) and dimerization (ZF5-6) have been extensively reported and result in human disease. Herein, we investigated IKZF1 mutations affecting protein stability.
View Article and Find Full Text PDFAllergol Select
October 2024
Center for Child and Adolescent Health, Helios Hospital Krefeld, Academic Hospital of RWTH Aachen, Krefeld.
Front Pediatr
May 2024
Department of Pediatrics, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
Heterozygous germline variants in human encoding for IKAROS define an inborn error of immunity with immunodeficiency, immune dysregulation and risk of malignancy with a broad phenotypic spectrum. Growing evidence of underlying pathophysiological genotype-phenotype correlations helps to improve our understanding of IKAROS-associated diseases. We describe 6 patients from 4 kindreds with two novel variants leading to haploinsufficiency from 3 centers in Germany.
View Article and Find Full Text PDFJ Clin Immunol
May 2024
Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan.
AIOLOS, encoded by the IKZF3 gene, belongs to the Ikaros zinc finger transcription factor family and plays a pivotal role in regulating lymphocyte development. Recently, heterozygous missense loss-of-function variants within the DNA-binding domain of the IKZF3 gene (G159R, N160S, and G191R) have been identified in patients with inborn errors of immunity (IEI). Additionally, a missense and a truncating variant (E82K and Q402X) leading to the AIOLOS haploinsufficiency have been documented.
View Article and Find Full Text PDF