1
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Elgaali E, Mezzavilla M, Ahmed I, Elanbari M, Ali A, Abdelaziz G, Fakhro KA, Saleh A, Ben-Omran T, Almulla N, Cugno C. Genetic background of primary and familial HLH in Qatar: registry data and population study. Front Pediatr 2024; 12:1326489. [PMID: 38808104 PMCID: PMC11130942 DOI: 10.3389/fped.2024.1326489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 04/08/2024] [Indexed: 05/30/2024] Open
Abstract
Background Familial hemophagocytic lymphohistiocytosis (FHLH) is an inherited life-threatening disease. Five types are identified, with the addition of congenital immunodeficiency syndromes in which HLH is a typical manifestation. The literature on this disease is very scarce in the Middle East, with only a few scattered reports. Methods We report detailed demographic, clinical, and genomic data from 28 patients diagnosed with primary and familial HLH over the last decade in Qatar. An evaluation was performed of allele frequencies of deleterious variants from 12 primary and familial HLH causative genes on the Qatar Genome Programme (QGP) cohort of 14,669 Qatari individuals. Results The genetic diagnosis was obtained in 15 patients, and four novel mutations in Perforin 1 (PRF1), UNC13D, LYST, and RAB27A genes were found. We identified 22,945 low/high/moderate/modifier impact variants significantly enriched in the QGP in those 12 genes. The variants rs1271079313 in PRF1 and rs753966933 in RAB27A found in our patient cohort were significantly more prevalent in the QGP compared to the Genome Aggregation Database (gnomAD) database, with a high carrier frequency in the Qatari population. Conclusions We established the first primary and familial HLH Registry in the Gulf Region and identified novel possibly pathogenic variants present at higher frequency in the Qatari population, which could be used for screening purposes. Raising awareness about primary and familial HLH and implementing screening activities in the Qatari highly inbred population could stem into more comprehensive premarital and prenatal evaluations and faster diagnosis.
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Affiliation(s)
- Elkhansa Elgaali
- Pediatric Hematology and Oncology Department, Sidra Medicine, Doha, Qatar
| | | | - Ikhlak Ahmed
- Research Department, Sidra Medicine, Doha, Qatar
| | | | - Aesha Ali
- Research Department, Sidra Medicine, Doha, Qatar
| | | | | | - Ayman Saleh
- Pediatric Hematology and Oncology Department, Sidra Medicine, Doha, Qatar
| | - Tawfeg Ben-Omran
- Division of Genetic and Genomic Medicine, Sidra Medicine, Doha, Qatar
- Department of Medical Genetics, Hamad Medical Corporation, Doha, Qatar
| | - Naima Almulla
- Pediatric Hematology and Oncology Department, Sidra Medicine, Doha, Qatar
| | - Chiara Cugno
- Pediatric Hematology and Oncology Department, Sidra Medicine, Doha, Qatar
- Research Department, Sidra Medicine, Doha, Qatar
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2
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Tomomasa D, Hiejima E, Miyamoto T, Tanita K, Matsuoka M, Niizato D, Mitsuiki N, Isoda T, Yasumi T, van Zelm MC, Morio T, Kanegane H. Recurrent tandem duplication of UNC13D in familial hemophagocytic lymphohistiocytosis type 3. Clin Immunol 2022; 242:109104. [PMID: 36041693 DOI: 10.1016/j.clim.2022.109104] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/03/2022]
Abstract
Familial hemophagocytic lymphohistiocytosis type 3 is a fatal inborn error of immunity due to abnormal cytotoxic activity of T and NK cells and is caused by variants in UNC13D, which encodes Munc13-4. One published case was reported to carry a tandem duplication of UNC13D exons 7-12, and we here present another case with the exact same duplication breakpoints. The patient carried the tandem duplication from maternal origin, and a c.2346_2349 variant on the paternal allele. Single nucleotide polymorphism analysis around UNC13D revealed that the allele with tandem duplication was most likely a founder allele. Transposable element analysis showed that the breakpoints occurred within Alu elements in introns 12 and 6. Multiple sequence alignment revealed that Alu elements containing the truncated points are highly homologous. Sequence homology was thought to be a factor predisposing to the tandem duplication variant.
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Affiliation(s)
- Dan Tomomasa
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Eitaro Hiejima
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takayuki Miyamoto
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kay Tanita
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Masaki Matsuoka
- Department of Pediatrics, Toho University Omori Medical Center, Tokyo, Japan
| | - Daiki Niizato
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Noriko Mitsuiki
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takeshi Isoda
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takahiro Yasumi
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Menno C van Zelm
- Department of Immunology and Pathology, Central Clinical School, Monash University and Alfred Hospital, Melbourne, VIC, Australia
| | - Tomohiro Morio
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Hirokazu Kanegane
- Department of Child Health and Development, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
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3
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Keegan NP, Wilton SD, Fletcher S. Analysis of Pathogenic Pseudoexons Reveals Novel Mechanisms Driving Cryptic Splicing. Front Genet 2022; 12:806946. [PMID: 35140743 PMCID: PMC8819188 DOI: 10.3389/fgene.2021.806946] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/09/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding pre-mRNA splicing is crucial to accurately diagnosing and treating genetic diseases. However, mutations that alter splicing can exert highly diverse effects. Of all the known types of splicing mutations, perhaps the rarest and most difficult to predict are those that activate pseudoexons, sometimes also called cryptic exons. Unlike other splicing mutations that either destroy or redirect existing splice events, pseudoexon mutations appear to create entirely new exons within introns. Since exon definition in vertebrates requires coordinated arrangements of numerous RNA motifs, one might expect that pseudoexons would only arise when rearrangements of intronic DNA create novel exons by chance. Surprisingly, although such mutations do occur, a far more common cause of pseudoexons is deep-intronic single nucleotide variants, raising the question of why these latent exon-like tracts near the mutation sites have not already been purged from the genome by the evolutionary advantage of more efficient splicing. Possible answers may lie in deep intronic splicing processes such as recursive splicing or poison exon splicing. Because these processes utilize intronic motifs that benignly engage with the spliceosome, the regions involved may be more susceptible to exonization than other intronic regions would be. We speculated that a comprehensive study of reported pseudoexons might detect alignments with known deep intronic splice sites and could also permit the characterisation of novel pseudoexon categories. In this report, we present and analyse a catalogue of over 400 published pseudoexon splice events. In addition to confirming prior observations of the most common pseudoexon mutation types, the size of this catalogue also enabled us to suggest new categories for some of the rarer types of pseudoexon mutation. By comparing our catalogue against published datasets of non-canonical splice events, we also found that 15.7% of pseudoexons exhibit some splicing activity at one or both of their splice sites in non-mutant cells. Importantly, this included seven examples of experimentally confirmed recursive splice sites, confirming for the first time a long-suspected link between these two splicing phenomena. These findings have the potential to improve the fidelity of genetic diagnostics and reveal new targets for splice-modulating therapies.
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Affiliation(s)
- Niall P. Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
- *Correspondence: Niall P. Keegan,
| | - Steve D. Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
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4
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Petersen USS, Doktor TK, Andresen BS. Pseudoexon activation in disease by non-splice site deep intronic sequence variation - wild type pseudoexons constitute high-risk sites in the human genome. Hum Mutat 2021; 43:103-127. [PMID: 34837434 DOI: 10.1002/humu.24306] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/02/2021] [Accepted: 11/06/2021] [Indexed: 12/27/2022]
Abstract
Accuracy of pre-messenger RNA (pre-mRNA) splicing is crucial for normal gene expression. Complex regulation supports the spliceosomal distinction between authentic exons and the many seemingly functional splice sites delimiting pseudoexons. Pseudoexons are nonfunctional intronic sequences that can be activated for aberrant inclusion in mRNA, which may cause disease. Pseudoexon activation is very challenging to predict, in particular when activation occurs by sequence variants that alter the splicing regulatory environment without directly affecting splice sites. As pseudoexon inclusion often evades detection due to activation of nonsense-mediated mRNA decay, and because conventional diagnostic procedures miss deep intronic sequence variation, pseudoexon activation is a heavily underreported disease mechanism. Pseudoexon characteristics have mainly been studied based on in silico predicted sequences. Moreover, because recognition of sequence variants that create or strengthen splice sites is possible by comparison with well-established consensus sequences, this type of pseudoexon activation is by far the most frequently reported. Here we review all known human disease-associated pseudoexons that carry functional splice sites and are activated by deep intronic sequence variants located outside splice site sequences. We delineate common characteristics that make this type of wild type pseudoexons distinct high-risk sites in the human genome.
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Affiliation(s)
- Ulrika S S Petersen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark
| | - Thomas K Doktor
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark
| | - Brage S Andresen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark
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5
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Bąbol-Pokora K, Wołowiec M, Popko K, Jaworowska A, Bryceson YT, Tesi B, Henter JI, Młynarski W, Badowska W, Balwierz W, Drabko K, Kałwak K, Maciejka-Kembłowska L, Pieczonka A, Sobol-Milejska G, Kołtan S, Malinowska I. Molecular Genetics Diversity of Primary Hemophagocytic Lymphohistiocytosis among Polish Pediatric Patients. Arch Immunol Ther Exp (Warsz) 2021; 69:31. [PMID: 34677667 PMCID: PMC8536594 DOI: 10.1007/s00005-021-00635-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/10/2021] [Indexed: 08/30/2023]
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of life-threatening inflammation caused by an excessive, prolonged and ineffective immune response. An increasing number of HLH cases is recognized in Poland, but the genetic causes of familial HLH (FHL) have not been reported. We investigated the molecular genetics and associated outcomes of pediatric patients who met HLH criteria. We studied 54 patients with HLH, 36 of whom received genetic studies. Twenty-five patients were subjected to direct sequencing of the PRF1, UNC13D, STX11, XIAP and SH2D1A genes. Additionally, 11 patients were subjected to targeted next-generation sequencing. In our study group, 17 patients (31%) were diagnosed with primary HLH, with bi-allelic FHL variants identified in 13 (36%) patients whereas hemizygous changes were identified in 4 patients with X-linked lymphoproliferative diseases. In addition, one patient was diagnosed with X-linked immunodeficiency with magnesium defect, Epstein–Barr virus infection and neoplasia due to a hemizygous MAGT1 variant; another newborn was diagnosed with auto-inflammatory syndrome caused by MVK variants. The majority (65%) of FHL patients carried UNC13D pathogenic variants, whereas PRF1 variants occurred in two patients. Novel variants in UNC13D, PRF1 and XIAP were detected. Epstein–Barr virus was the most common trigger noted in 23 (65%) of the patients with secondary HLH. In three patients with secondary HLH, heterozygous variants of FHL genes were found. Overall survival for the entire study group was 74% with a median of 3.6 years of follow-up. Our results highlight the diversity of molecular causes of primary HLH in Poland.
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Affiliation(s)
- Katarzyna Bąbol-Pokora
- Department of Pediatrics, Oncology and Hematology, Medical University of Lodz, Lodz, Poland
| | - Magdalena Wołowiec
- Department of Pediatrics, Hematology and Oncology, Medical University of Warsaw, Żwirki i Wigury 63A, 02-091, Warsaw, Poland
| | - Katarzyna Popko
- Department of Laboratory Diagnostics and Clinical Immunology of Developmental Age, Medical University of Warsaw, Warsaw, Poland
| | - Aleksandra Jaworowska
- Department of Pediatrics, Oncology and Hematology, Medical University of Lodz, Lodz, Poland
| | - Yenan T Bryceson
- Department of Medicine, Centre for Hematology and Regenerative Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Bianca Tesi
- Department of Medicine, Centre for Hematology and Regenerative Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Jan-Inge Henter
- Department of Medicine, Centre for Hematology and Regenerative Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Wojciech Młynarski
- Department of Pediatrics, Oncology and Hematology, Medical University of Lodz, Lodz, Poland
| | - Wanda Badowska
- Division of Pediatric Hematology and Oncology, Children Hospital, Olsztyn, Poland
| | - Walentyna Balwierz
- Department of Pediatrics Oncology and Hematology, University Children's Hospital, Jagiellonian University Collegium Medicum, Krakow, Poland
| | - Katarzyna Drabko
- Department of Pediatric Hematology, Oncology and Stem Cell Transplantation, Medical University of Lublin, Lublin, Poland
| | - Krzysztof Kałwak
- Department of Pediatric Stem Cell Transplantation, Hematology and Oncology, Medical University, Wroclaw, Poland
| | | | - Anna Pieczonka
- Department of Pediatric Oncology, Hematology and Transplantology, University of Medical Sciences, Poznan, Poland
| | - Grażyna Sobol-Milejska
- Department of Pediatrics, Hematology and Oncology, Medical University of Silesia, Silesia, Poland
| | - Sylwia Kołtan
- Department of Pediatrics, Hematology and Oncology, Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland
| | - Iwona Malinowska
- Department of Pediatrics, Hematology and Oncology, Medical University of Warsaw, Żwirki i Wigury 63A, 02-091, Warsaw, Poland.
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6
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Amirifar P, Ranjouri MR, Abolhassani H, Moeini Shad T, Almasi-Hashiani A, Azizi G, Moamer S, Aghamohammadi A, Yazdani R. Clinical, immunological and genetic findings in patients with UNC13D deficiency (FHL3): A systematic review. Pediatr Allergy Immunol 2021; 32:186-197. [PMID: 32679608 DOI: 10.1111/pai.13323] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Familial hemophagocytic lymphohistiocytosis (FHL) is a rare autosomal recessive immune disorder that is caused by mutations in 6 different genes related to the formation and function of secretory lysosomes within cytotoxic T lymphocytes and natural killer (NK) cells. Thus, defect in these genes is associated with the accumulation of antigens due to defective cytotoxic function. FHL type 3 (FHL3) accounts for nearly 30-40% of FHL, and its underlying reason is mutation in UNC13D gene which encodes Munc13-4 protein. METHODS For the first time, we aimed to systematically review clinical features, immunologic data, and genetic findings of patients with FHL3. We conducted electronic searches for English-language articles in PubMed, Web of Science, EMBASE, and Scopus databases to collect comprehensive records related to patients with UNC13D mutations. RESULTS A total of 279 abstracts were initially reviewed for inclusion. Among them, 57 articles corresponding to 322 individual FHL3 patients fulfilled our selection criteria. Finally, 73 and 249 patients were considered as severe and mild feature groups, respectively. Our results confirmed that fever, hepatosplenomegaly, and hemophagocytosis are common clinical features in the disease. Moreover, reduced fibrinogen and NK cell activity, as well as increased ferritin and triglycerides, are important markers for early diagnosis of the FHL3 disease. Investigation of genotype showed that the most prevalent type and zygosity of UNC13D are splice-site errors and compound heterozygous, respectively. CONCLUSION FHL3 patients have a wide range of clinical manifestations, which makes it difficult to diagnose. Therefore, it seems that the sequencing of the entire UNC13D gene (coding and non-coding regions) is the most appropriate way to accurate diagnosis of FHL3 patients.
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Affiliation(s)
- Parisa Amirifar
- Department of Medical Genetics, School of Medicine, Tehran University of medical sciences, Tehran, Iran.,Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Ranjouri
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Abolhassani
- Research Center for Primary Immunodeficiencies, Iran University of medical sciences, Tehran, Iran.,Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institute at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Tannaz Moeini Shad
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Gholamreza Azizi
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.,Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Soraya Moamer
- School of Public Health, Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Asghar Aghamohammadi
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Yazdani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
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7
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Frequency and spectrum of disease-causing variants in 1892 patients with suspected genetic HLH disorders. Blood Adv 2020; 4:2578-2594. [PMID: 32542393 PMCID: PMC7322966 DOI: 10.1182/bloodadvances.2020001605] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/10/2020] [Indexed: 01/13/2023] Open
Abstract
This article explores the distribution and mutation spectrum of potential disease-causing genetic variants in hemophagocytic lymphohistiocytosis (HLH)-associated genes observed in a large tertiary clinical referral laboratory. Samples from 1892 patients submitted for HLH genetic analysis were studied between September 2013 and June 2018 using a targeted next-generation sequencing panel approach. Patients ranged in age from 1 day to 78 years. Analysis included 15 genes associated with HLH. A potentially causal genetic finding was observed in 227 (12.0%) samples in this cohort. A total of 197 patients (10.4%) had a definite genetic diagnosis. Patients with pathogenic variants in familial HLH genes tended to be diagnosed significantly younger compared with other genes. Pathogenic or likely pathogenic variants in the PRF1 gene were the most frequent. However, mutations in genes associated with degranulation defects (STXBP2, UNC13D, RAB27A, LYST, and STX11) were more common than previously appreciated and collectively represented >50% of cases. X-linked conditions (XIAP, SH2D1A, and MAGT1) accounted for 17.8% of the 197 cases. Pathogenic variants in the SLC7A7 gene were the least encountered. These results describe the largest cohort of genetic variation associated with suspected HLH in North America. Merely 10.4% of patients were identified with a clearly genetic cause by this diagnostic approach; other possible etiologies of HLH should be investigated. These results suggest that careful thought should be given regarding whether patients have a clinical phenotype most consistent with HLH vs other clinical and disease phenotypes. The gene panel identified known pathogenic and novel variants in 10 HLH-associated genes.
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8
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Lin H, Hargreaves KA, Li R, Reiter JL, Wang Y, Mort M, Cooper DN, Zhou Y, Zhang C, Eadon MT, Dolan ME, Ipe J, Skaar TC, Liu Y. RegSNPs-intron: a computational framework for predicting pathogenic impact of intronic single nucleotide variants. Genome Biol 2019; 20:254. [PMID: 31779641 PMCID: PMC6883696 DOI: 10.1186/s13059-019-1847-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 10/03/2019] [Indexed: 12/27/2022] Open
Abstract
Single nucleotide variants (SNVs) in intronic regions have yet to be systematically investigated for their disease-causing potential. Using known pathogenic and neutral intronic SNVs (iSNVs) as training data, we develop the RegSNPs-intron algorithm based on a random forest classifier that integrates RNA splicing, protein structure, and evolutionary conservation features. RegSNPs-intron showed excellent performance in evaluating the pathogenic impacts of iSNVs. Using a high-throughput functional reporter assay called ASSET-seq (ASsay for Splicing using ExonTrap and sequencing), we evaluate the impact of RegSNPs-intron predictions on splicing outcome. Together, RegSNPs-intron and ASSET-seq enable effective prioritization of iSNVs for disease pathogenesis.
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Affiliation(s)
- Hai Lin
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Katherine A Hargreaves
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA
| | - Rudong Li
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Jill L Reiter
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Yue Wang
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Matthew Mort
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - David N Cooper
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Yaoqi Zhou
- Institute for Glycomics and School of Informatics and Communication Technology, Griffith University, Parklands Dr., Southport, QLD, 4215, Australia
| | - Chi Zhang
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Michael T Eadon
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - M Eileen Dolan
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, 60637, USA
| | - Joseph Ipe
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA
| | - Todd C Skaar
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA.
| | - Yunlong Liu
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA.
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9
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Chen X, Wang F, Zhang Y, Teng W, Wang M, Nie D, Zhou X, Wang D, Zhao H, Zhu P, Liu H. Genetic variant spectrum in 265 Chinese patients with hemophagocytic lymphohistiocytosis: Molecular analyses of PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP. Clin Genet 2018; 94:200-212. [PMID: 29665027 DOI: 10.1111/cge.13363] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 12/12/2022]
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening hyperinflammatory disease. This study aimed to investigate the frequencies and distributions of inherited variants in PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP genes in Chinese patients with HLH. A total of 265 patients diagnosed with HLH from January, 2010 to December, 2016 were recruited and analyzed for the 6 genes. Genetic variants were observed in 87 (32.83%) patients. 36 (13.58%) exhibited variants in UNC13D, 18 (6.79%) exhibited PRF1 variants, 10 (3.77%) had variants in XIAP, 9 (3.40%) exhibited variants in STXBP2, 6 (2.26%) carried variants in SH2D1A, 1 (0.38%) had STX11 variant, and 7 (2.64%) exhibited digenic variants. Monoallelic variants were the most common, which accounted for 49.43% of all cases with variants. All variants were confirmed to be germline-derived. The present study describes a distinct variant spectrum in Chinese patients with HLH, whereby UNC13D is the most frequently mutated gene with missense variants that are the most common molecular defects. The variant profile of Chinese HLH patients is quite different from that of Western cohorts but similar to that of Korean patients, yet showing its own uniqueness. This racial difference shows the role of genetic background in the occurrence of HLH.
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Affiliation(s)
- X Chen
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - F Wang
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - Y Zhang
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - W Teng
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - M Wang
- Department of Hematology, Peking University First Hospital, Beijing, China
| | - D Nie
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - X Zhou
- Department of Immunotherapy, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - D Wang
- Department of Immunotherapy, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - H Zhao
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China
| | - P Zhu
- Department of Hematology, Peking University First Hospital, Beijing, China
| | - H Liu
- Department of Pathology and Laboratory Medicine Division, Hebei Yanda Lu Daopei Hospital, Langfang, China.,Translational Medicine Research Center, Beijing Lu Daopei Institute of Hematology, Beijing, China
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10
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Hiejima E, Shibata H, Yasumi T, Shimodera S, Hori M, Izawa K, Kawai T, Matsuoka M, Kojima Y, Ohara A, Nishikomori R, Ohara O, Heike T. Characterization of a large UNC13D gene duplication in a patient with familial hemophagocytic lymphohistiocytosis type 3. Clin Immunol 2018; 191:63-66. [PMID: 29596912 DOI: 10.1016/j.clim.2018.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/05/2017] [Accepted: 03/21/2018] [Indexed: 02/06/2023]
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) type 3 is a life-threatening immune dysregulation syndrome caused by mutations in the UNC13D gene, encoding the munc13-4 protein, which is important for function of cytotoxic lymphocytes. FHL3 accounts for 30-40% of FHL cases, and more than 100 mutations in the UNC13D gene have been described to date. We describe the first case of FHL3 carrying an intragenic duplication of UNC13D, apparently mediated by recombination of Alu elements. NK cell degranulation and munc13-4 protein expression assays are useful for early identification of such mutations, which may be missed by analysis of genomic DNA alone.
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Affiliation(s)
- Eitaro Hiejima
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hirofumi Shibata
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahiro Yasumi
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Saeko Shimodera
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masayuki Hori
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kazushi Izawa
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomoki Kawai
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masaki Matsuoka
- Department of Pediatrics, Toho University Ohmori Medical Center, Tokyo, Japan
| | - Yasuko Kojima
- Department of Pediatrics, Toho University Ohmori Medical Center, Tokyo, Japan
| | - Akira Ohara
- Department of Pediatrics, Toho University Ohmori Medical Center, Tokyo, Japan
| | - Ryuta Nishikomori
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Osamu Ohara
- Laboratory for Integrative Genomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan; Department of Human Genome Research, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Toshio Heike
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
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11
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Human CTL-based functional analysis shows the reliability of a munc13-4 protein expression assay for FHL3 diagnosis. Blood 2018; 131:2016-2025. [PMID: 29549174 DOI: 10.1182/blood-2017-10-812503] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 03/05/2018] [Indexed: 01/09/2023] Open
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is the major form of hereditary hemophagocytic lymphohistiocytosis (HLH); as such, it requires prompt and accurate diagnosis. We previously reported that FHL type 3 (FHL3) can be rapidly screened by detecting munc13-4 expression in platelets using flow cytometry; however, the reliability of the munc13-4 expression assay for FHL3 diagnosis is unclear. Regardless of the type of UNC13D mutation, all reported FHL3 cases examined for the munc13-4 protein showed significantly reduced expression. However, the translated munc13-4 protein of some reportedly disease-causing UNC13D missense variants has not been assessed in terms of expression or function; therefore, their clinical significance remains unclear. The aim of this study was to determine the reliability of a munc13-4 expression assay for screening FHL3. Between 2011 and 2016, 108 HLH patients were screened by this method in our laboratory, and all 15 FHL3 patients were diagnosed accurately. To further elucidate whether munc13-4 expression analysis can reliably identify FHL3 patients harboring missense mutations in UNC13D, we developed an alloantigen-specific cytotoxic T lymphocyte (CTL) line and a CTL line immortalized by Herpesvirus saimiri derived from FHL3 patients. We then performed a comprehensive functional analysis of UNC13D variants. Transient expression of UNC13D complementary DNA constructs in these cell lines enabled us to determine the pathogenicity of the reported UNC13D missense variants according to expression levels of their translated munc13-4 proteins. Taken together with previous findings, the results presented herein show that the munc13-4 protein expression assay is a reliable tool for FHL3 screening.
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12
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Cetica V, Sieni E, Pende D, Danesino C, De Fusco C, Locatelli F, Micalizzi C, Putti MC, Biondi A, Fagioli F, Moretta L, Griffiths GM, Luzzatto L, Aricò M. Genetic predisposition to hemophagocytic lymphohistiocytosis: Report on 500 patients from the Italian registry. J Allergy Clin Immunol 2015; 137:188-196.e4. [PMID: 26342526 PMCID: PMC4699615 DOI: 10.1016/j.jaci.2015.06.048] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 06/04/2015] [Accepted: 06/10/2015] [Indexed: 12/31/2022]
Abstract
BACKGROUND Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease affecting mostly children but also adults and characterized by hyperinflammatory features. A subset of patients, referred to as having familial hemophagocytic lymphohistiocytosis (FHL), have various underlying genetic abnormalities, the frequencies of which have not been systematically determined previously. OBJECTIVE This work aims to further our understanding of the pathogenic bases of this rare condition based on an analysis of our 25 years of experience. METHODS From our registry, we have analyzed a total of 500 unselected patients with HLH. RESULTS Biallelic pathogenic mutations defining FHL were found in 171 (34%) patients; the proportion of FHL was much higher (64%) in patients given a diagnosis during the first year of life. Taken together, mutations of the genes PRF1 (FHL2) and UNC13D (FHL3) accounted for 70% of cases of FHL. Overall, a genetic diagnosis was possible in more than 90% of our patients with FHL. Perforin expression and the extent of degranulation have been more useful for diagnosing FHL than hemophagocytosis and the cytotoxicity assay. Of 281 (56%) patients classified as having "sporadic" HLH, 43 had monoallelic mutations in one of the FHL-defining genes. Given this gene dosage effect, FHL is not strictly recessive. CONCLUSION We suggest that the clinical syndrome HLH generally results from the combined effects of an exogenous trigger and genetic predisposition. Within this combination, different weights of exogenous and genetic factors account for the wide disease spectrum that ranges from HLH secondary to severe infection to FHL.
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Affiliation(s)
- Valentina Cetica
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital, Florence, Italy
| | - Elena Sieni
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital, Florence, Italy
| | - Daniela Pende
- Istituto di Ricovero e Cura a Carattere Scientifico Azienda Ospedaliera Universitaria San Martino-Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy
| | - Cesare Danesino
- Medical Genetics, Department of Molecular Medicine, University of Pavia and Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Carmen De Fusco
- Pediatric Hematology and Oncology, Pausilipon Hospital, Naples, Italy
| | - Franco Locatelli
- Department of Pediatric Hematology and Oncology, IRCCS Ospedale Pediatrico Bambino Gesù, Rome, and the University of Pavia, Pavia, Italy
| | | | | | - Andrea Biondi
- Pediatric Clinic, University of Milan Bicocca, San Gerardo Hospital/Fondazione MBBM, Monza, Italy
| | - Franca Fagioli
- Pediatric Onco-Hematology, Stem Cell Transplantation and Cellular Therapy Division, Regina Margherita Children's Hospital, Turin, Italy
| | | | - Gillian M Griffiths
- Cambridge Institute for Medical Research, University of Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, United Kingdom
| | | | - Maurizio Aricò
- Istituto Toscano Tumori (I.T.T.), Florence, Italy; Azienda Sanitaria Provinciale, Ragusa, Italy.
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Bioinformatics tools for discovery and functional analysis of single nucleotide polymorphisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 827:287-310. [PMID: 25387971 DOI: 10.1007/978-94-017-9245-5_17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
With the high speed DNA sequencing of genome, databases of genome data continue to grow, and the understanding of genetic variation between individuals grows as well. Single nucleotide polymorphisms (SNPs), a main type of genetic variation, are increasingly important resource for understanding the structure and function of the human genome and become a valuable resource for investigating the genetic basis of disease. During the past years, in addition to experimental approaches to characterize specific variants, intense bioinformatics techniques were applied to understand effects of these genetic changes. In the genetics studies, one intends to understand the molecular basis of disease, and computational methods are becoming increasingly important for SNPs selection, prediction and understanding the downstream effects of genetic variation. The review provides systematic information on the available resources and methods for SNPs discovery and analysis. We also report some new results on DNA sequence-based prediction of SNPs in human cytochrome P450, which serves as an example of computational methods to predict and discovery SNPs. Additionally, annotation and prediction of functional SNPs, as well as a comprehensive list of existing tools and online recourses, are reviewed and described.
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14
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Abstract
Hemophagocytic lymphohistiocytosis (HLH) covers a wide array of related life-threatening conditions featuring ineffective immunity characterized by an uncontrolled hyperinflammatory response. HLH is often triggered by infection. Familial forms result from genetic defects in natural killer cells and cytotoxic T-cells, typically affecting perforin and intracellular vesicles. HLH is likely under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy to be made. Current treatment regimens include immunosuppression, immune modulation, chemotherapy, and biological response modification, followed by hematopoietic stem-cell transplant (bone marrow transplant). A number of recent studies have contributed to the understanding of HLH pathophysiology, leading to alternate treatment options; however, much work remains to raise awareness and improve the high morbidity and mortality of these complex conditions.
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Affiliation(s)
- Melissa R George
- Department of Pathology, Penn State Milton S Hershey Medical Center, Hershey, PA, USA
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15
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Qian Y, Johnson JA, Connor JA, Valencia CA, Barasa N, Schubert J, Husami A, Kissell D, Zhang G, Weirauch MT, Filipovich AH, Zhang K. The 253-kb inversion and deep intronic mutations in UNC13D are present in North American patients with familial hemophagocytic lymphohistiocytosis 3. Pediatr Blood Cancer 2014; 61:1034-40. [PMID: 24470399 DOI: 10.1002/pbc.24955] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 12/23/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND The mutations in UNC13D are responsible for familial hemophagocytic lymphohistiocytosis (FHL) type 3. A 253-kb inversion and two deep intronic mutations, c.118-308C > T and c.118-307G > A, in UNC13D were recently reported in European and Asian FHL3 patients. We sought to determine the prevalence of these three non-coding mutations in North American FHL patients and evaluate the significance of examining these new mutations in genetic testing. PROCEDURE We performed DNA sequencing of UNC13D and targeted analysis of these three mutations in 1,709 North American patients with a suspected clinical diagnosis of hemophagocytic lymphohistiocytosis (HLH). RESULTS The 253-kb inversion, intronic mutations c.118-308C > T and c.118-307G > A were found in 11, 15, and 4 patients, respectively, in which the genetic basis (bi-allelic mutations) explained 25 additional patients. Taken together with previously diagnosed FHL3 patients in our HLH patient registry, these three non-coding mutations were found in 31.6% (25/79) of the FHL3 patients. The 253-kb inversion, c.118-308C > T and c.118-307G > A accounted for 7.0%, 8.9%, and 1.3% of mutant alleles, respectively. Significantly, eight novel mutations in UNC13D are being reported in this study. To further evaluate the expression level of the newly reported intronic mutation c.118-307G > A, reverse transcription PCR and Western blot analysis revealed a significant reduction of both RNA and protein levels suggesting that the c.118-307G > A mutation affects transcription. CONCLUSIONS These specified non-coding mutations were found in a significant number of North American patients and inclusion of them in mutation analysis will improve the molecular diagnosis of FHL3.
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Affiliation(s)
- Yaping Qian
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, Ohio
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16
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Cichocki F, Schlums H, Li H, Stache V, Holmes T, Lenvik TR, Chiang SCC, Miller JS, Meeths M, Anderson SK, Bryceson YT. Transcriptional regulation of Munc13-4 expression in cytotoxic lymphocytes is disrupted by an intronic mutation associated with a primary immunodeficiency. ACTA ACUST UNITED AC 2014; 211:1079-91. [PMID: 24842371 PMCID: PMC4042637 DOI: 10.1084/jem.20131131] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A conserved regulatory element in intron 1 of UNC13D regulates Munc13-4 expression. Autosomal recessive mutations in UNC13D, the gene that encodes Munc13-4, are associated with familial hemophagocytic lymphohistiocytosis type 3 (FHL3). Munc13-4 expression is obligatory for exocytosis of lytic granules, facilitating cytotoxicity by T cells and natural killer (NK) cells. The mechanisms regulating Munc13-4 expression are unknown. Here, we report that Munc13-4 is highly expressed in differentiated human NK cells and effector CD8+ T lymphocytes. A UNC13D c.118-308C>T mutation, causative of FHL3, disrupted binding of the ETS family member ELF1 to a conserved intronic sequence. This mutation impairs UNC13D intron 1 recruitment of STAT4 and the chromatin remodeling complex component BRG1, diminishing active histone modifications at the locus. The intronic sequence acted as an overall enhancer of Munc13-4 expression in cytotoxic lymphocytes in addition to representing an alternative promoter encoding a novel Munc13-4 isoform. Mechanistically, T cell receptor engagement facilitated STAT4-dependent Munc13-4 expression in naive CD8+ T lymphocytes. Collectively, our data demonstrates how chromatin remodeling within an evolutionarily conserved regulatory element in intron 1 of UNC13D regulates the induction of Munc13-4 expression in cytotoxic lymphocytes and suggests that an alternative Munc13-4 isoform is required for lymphocyte cytotoxicity. Thus, mutations associated with primary immunodeficiencies may cause disease by disrupting transcription factor binding.
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Affiliation(s)
- Frank Cichocki
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455
| | - Heinrich Schlums
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
| | - Hongchuan Li
- Basic Science Program, Leidos Biomedical Research, Inc., Laboratory of Experimental Immunology, SAIC-Frederick Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Vanessa Stache
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
| | - Timothy Holmes
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
| | - Todd R Lenvik
- Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455
| | - Samuel C C Chiang
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
| | - Jeffrey S Miller
- Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455
| | - Marie Meeths
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital Solna, 171 76 Stockholm, Sweden
| | - Stephen K Anderson
- Basic Science Program, Leidos Biomedical Research, Inc., Laboratory of Experimental Immunology, SAIC-Frederick Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Yenan T Bryceson
- Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Broegelmann Research Laboratory, Clinical Institute, University of Bergen, N-5021 Bergen, Norway
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17
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Alsina L, Colobran R, de Sevilla MF, Català A, Viñas L, Ricart S, Plaza AM, Lois S, Juan M, Pujol-Borrell R, Martinez-Gallo M. Novel and atypical splicing mutation in a compound heterozygous UNC13D defect presenting in Familial Hemophagocytic Lymphohistiocytosis triggered by EBV infection. Clin Immunol 2014; 153:292-7. [PMID: 24825797 DOI: 10.1016/j.clim.2014.04.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 04/28/2014] [Accepted: 04/30/2014] [Indexed: 11/19/2022]
Abstract
Familial Hemophagocytic Lymphohistiocytosis type 3 (FHL3) is a genetic disorder caused by mutations in UNC13D gene, coding the granule priming factor Munc13-4 that intervenes in NK and T cell cytotoxic function. Here we report the case of a 17-month-old girl with prolonged symptomatic EBV infectious mononucleosis and clinical symptoms of hemophagocytic syndrome. In vitro functional analysis pointed to a degranulation defect. The genetic analysis of UNC13D gene identified initially a heterozygous mutation (c.753+1G>T) in the donor splice-site that resulted in exon 9 skipping (maternal allele). Mutations in other genes were considered, but additional analysis of UNC13D cDNA revealed in the paternal allele a heterozygous transition from G to A (c.2448-13G>A) at the 3' acceptor splice-site in intron 25, generating a new acceptor splice-site that leads to a frameshift and a premature STOP codon. Allele specific amplification of the cDNA confirmed the absence of a functional mRNA from the paternal allele. This case illustrates an atypical compound heterozygous UNC13D mutation affecting the RNA splicing that generates a typical FHL3 phenotype.
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Affiliation(s)
- L Alsina
- Allergy and Clinical Immunology, Universitat de Barcelona, Barcelona, Spain; Immunology Functional Unit, SJD-Clínic, Barcelona, Spain
| | - R Colobran
- Deparment of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain; Immunology Division Hospital Universitari Vall d'Hebron, Barcelona, Spain; Vall d'Hebron Institut de Recerca, Barcelona, Spain
| | - M F de Sevilla
- Paediatric Department, Universitat de Barcelona, Barcelona, Spain
| | - A Català
- Hematology Department, Hospital Sant Joan de Déu., Universitat de Barcelona, Barcelona, Spain
| | - L Viñas
- Deparment of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - S Ricart
- Paediatric Department, Universitat de Barcelona, Barcelona, Spain
| | - A M Plaza
- Allergy and Clinical Immunology, Universitat de Barcelona, Barcelona, Spain; Immunology Functional Unit, SJD-Clínic, Barcelona, Spain
| | - S Lois
- Research Unit in Translational Bioinformatics in Neurosciences, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Juan
- Immunology Functional Unit, SJD-Clínic, Barcelona, Spain; Immunology Department, Hospital Clinic, Universitat de Barcelona - IDIBAPS, Barcelona, Spain
| | - R Pujol-Borrell
- Deparment of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain; Immunology Division Hospital Universitari Vall d'Hebron, Barcelona, Spain; Vall d'Hebron Institut de Recerca, Barcelona, Spain.
| | - M Martinez-Gallo
- Deparment of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain; Immunology Division Hospital Universitari Vall d'Hebron, Barcelona, Spain; Vall d'Hebron Institut de Recerca, Barcelona, Spain
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18
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Sieni E, Cetica V, Hackmann Y, Coniglio ML, Da Ros M, Ciambotti B, Pende D, Griffiths G, Aricò M. Familial hemophagocytic lymphohistiocytosis: when rare diseases shed light on immune system functioning. Front Immunol 2014; 5:167. [PMID: 24795715 PMCID: PMC3997030 DOI: 10.3389/fimmu.2014.00167] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 03/29/2014] [Indexed: 12/03/2022] Open
Abstract
The human immune system depends on the activity of cytotoxic T lymphocytes (CTL), natural killer (NK) cells, and NKT cells in order to fight off a viral infection. Understanding the molecular mechanisms during this process and the role of individual proteins was greatly improved by the study of familial hemophagocytic lymphohistiocytosis (FHL). Since 1999, genetic sequencing is the gold standard to classify patients into different subgroups of FHL. The diagnosis, once based on a clinical constellation of abnormalities, is now strongly supported by the results of a functional flow-cytometry screening, which directs the genetic study. A few additional congenital immune deficiencies can also cause a resembling or even identical clinical picture to FHL. As in many other rare human disorders, the collection and analysis of a relatively large number of cases in registries is crucial to draw a complete picture of the disease. The conduction of prospective therapeutic trials allows investigators to increase the awareness of the disease and to speed up the diagnostic process, but also provides important functional and genetic confirmations. Children with confirmed diagnosis may undergo hematopoietic stem cell transplantation, which is the only cure known to date. Moreover, detailed characterization of these rare patients helped to understand the function of individual proteins within the exocytic machinery of CTL, NK, and NKT cells. Moreover, identification of these genotypes also provides valuable information on variant phenotypes, other than FHL, associated with biallelic and monoallelic mutations in the FHL-related genes. In this review, we describe how detailed characterization of patients with genetic hemophagocytic lymphohistiocytosis has resulted in improvement in knowledge regarding contribution of individual proteins to the functional machinery of cytotoxic T- and NK-cells. The review also details how identification of these genotypes has provided valuable information on variant phenotypes.
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Affiliation(s)
- Elena Sieni
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital , Florence , Italy
| | - Valentina Cetica
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital , Florence , Italy ; Pediatric Hematology Oncology Network, Istituto Toscano Tumori (I.T.T.) , Florence , Italy
| | - Yvonne Hackmann
- Cambridge Institute for Medical Research, University of Cambridge Biomedical Campus , Cambridge , UK
| | - Maria Luisa Coniglio
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital , Florence , Italy
| | - Martina Da Ros
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital , Florence , Italy
| | - Benedetta Ciambotti
- Department Pediatric Hematology Oncology, Azienda Ospedaliero-Universitaria Meyer Children Hospital , Florence , Italy
| | - Daniela Pende
- Istituto di Ricovero e Cura a Carattere Scientifico Azienda Ospedaliera Universitaria San Martino-Istituto Nazionale per la Ricerca sul Cancro , Genoa , Italy
| | - Gillian Griffiths
- Cambridge Institute for Medical Research, University of Cambridge Biomedical Campus , Cambridge , UK
| | - Maurizio Aricò
- Pediatric Hematology Oncology Network, Istituto Toscano Tumori (I.T.T.) , Florence , Italy
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19
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Gupta S, Weitzman S. Primary and secondary hemophagocytic lymphohistiocytosis: clinical features, pathogenesis and therapy. Expert Rev Clin Immunol 2014; 6:137-54. [PMID: 20383897 DOI: 10.1586/eci.09.58] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sumit Gupta
- Division of Haematology/Oncology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
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20
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Seo JY, Song JS, Lee KO, Won HH, Kim JW, Kim SH, Lee SH, Yoo KH, Sung KW, Koo HH, Kang HJ, Shin HY, Ahn HS, Han DK, Kook H, Hwang TJ, Lyu CJ, Lee MJ, Kim JY, Park SS, Lim YT, Kim BE, Koh KN, Im HJ, Seo JJ, Kim HJ. Founder effects in two predominant intronic mutations of UNC13D, c.118-308C>T and c.754-1G>C underlie the unusual predominance of type 3 familial hemophagocytic lymphohistiocytosis (FHL3) in Korea. Ann Hematol 2012. [DOI: 10.1007/s00277-012-1628-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Bode SF, Lehmberg K, Maul-Pavicic A, Vraetz T, Janka G, Stadt UZ, Ehl S. Recent advances in the diagnosis and treatment of hemophagocytic lymphohistiocytosis. Arthritis Res Ther 2012; 14:213. [PMID: 22682420 PMCID: PMC3446494 DOI: 10.1186/ar3843] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages secreting high amounts of inflammatory cytokines. It is a frequent manifestation in patients with predisposing genetic defects, but can occur secondary to various infectious, malignant, and autoimmune triggers in patients without a known genetic predisposition. Clinical hallmarks are prolonged fever, cytopenias, hepatosplenomegaly, and neurological symptoms, but atypical variants presenting with signs of chronic immunodeficiency are increasingly recognized. Impaired secretion of perforin is a key feature in several genetic forms of the disease, but not required for disease pathogenesis. Despite progress in diagnostics and therapy, mortality of patients with severe HLH is still above 40%. Reference treatment is an etoposide-based protocol, but new approaches are currently explored. Key for a favorable prognosis is the rapid identification of an underlying genetic cause, which has been facilitated by recent immunological and genetic advances. In patients with predisposing genetic disease, hematopoietic stem cell transplantation is performed increasingly with reduced intensity conditioning regimes. Current research aims at a better understanding of disease pathogenesis and evaluation of more targeted approaches to therapy, including anti-cytokine antibodies and gene therapy.
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Affiliation(s)
- Sebastian Fn Bode
- Centre of Chronic Immunodeficiency, University Medical Center Freiburg, D-79106 Freiburg, Germany
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22
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A prospective evaluation of degranulation assays in the rapid diagnosis of familial hemophagocytic syndromes. Blood 2012; 119:2754-63. [PMID: 22294731 DOI: 10.1182/blood-2011-08-374199] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is a life-threatening disorder of immune regulation caused by defects in lymphocyte cytotoxicity. Rapid differentiation of primary, genetic forms from secondary forms of hemophagocytic lymphohistiocytosis (HLH) is crucial for treatment decisions. We prospectively evaluated the performance of degranulation assays based on surface up-regulation of CD107a on natural killer (NK) cells and cytotoxic T lymphocytes in a cohort of 494 patients referred for evaluation for suspected HLH. Seventy-five of 77 patients (97%) with FHL3-5 and 11 of 13 patients (85%) with Griscelli syndrome type 2 or Chediak-Higashi syndrome had abnormal resting NK-cell degranulation. In contrast, NK-cell degranulation was normal in 14 of 16 patients (88%) with X-linked lymphoproliferative disease and in 8 of 14 patients (57%) with FHL2, who were identified by diminished intracellular SLAM-associated protein (SAP), X-linked inhibitor of apoptosis protein (XIAP), and perforin expression, respectively. Among 66 patients with a clinical diagnosis of secondary HLH, 13 of 59 (22%) had abnormal resting NK-cell degranulation, whereas 0 of 43 had abnormal degranulation using IL-2-activated NK cells. Active disease or immunosuppressive therapy did not impair the assay performance. Overall, resting NK-cell degranulation below 5% provided a 96% sensitivity for a genetic degranulation disorder and a specificity of 88%. Therefore, degranulation assays allow a rapid and reliable classification of patients, benefiting treatment decisions.
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Sieni E, Cetica V, Mastrodicasa E, Pende D, Moretta L, Griffiths G, Aricò M. Familial hemophagocytic lymphohistiocytosis: a model for understanding the human machinery of cellular cytotoxicity. Cell Mol Life Sci 2012; 69:29-40. [PMID: 21990010 PMCID: PMC11114696 DOI: 10.1007/s00018-011-0835-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 09/13/2011] [Accepted: 09/13/2011] [Indexed: 02/03/2023]
Abstract
Cytotoxic T lymphocytes, natural killer cells, and NKT cells are effector cells able to kill infected cells. In some inherited human disorders, a defect in selected proteins involved in the cellular cytotoxicity mechanism results in specific clinical syndromes, grouped under the name of familial hemophagocytic lymphohistiocytosis. Recent advances in genetic studies of these patients has allowed the identification of different genetic subsets. Additional genetic immune deficiencies may also induce a similar clinical picture. International cooperation and prospective trials resulted in refining the diagnostic and therapeutic approach to these rare diseases with improved outcome but also with improved knowledge of the mechanisms underlying granule-mediated cellular cytotoxicity in humans.
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Affiliation(s)
- Elena Sieni
- Dipartimento Oncoematologia Pediatrica e Cure Domiciliari, Azienda Ospedaliero-Universitaria Meyer, Viale Pieraccini, 24, 50139 Florence, Italy
| | - Valentina Cetica
- Dipartimento Oncoematologia Pediatrica e Cure Domiciliari, Azienda Ospedaliero-Universitaria Meyer, Viale Pieraccini, 24, 50139 Florence, Italy
| | - Elena Mastrodicasa
- S.C. di Oncoematologia Pediatrica con Trapianto di CSE, Ospedale “S.M. della Misericordia” A.O, Perugia, Italy
| | - Daniela Pende
- A.O.U. San Martino-IST, Istituto Nazionale Ricerca sul Cancro, Genoa, Italy
| | | | - Gillian Griffiths
- Cambridge Institute for Medical Research, Addenbrooke’s Hospital, Cambridge, CB2 0XY UK
| | - Maurizio Aricò
- Dipartimento Oncoematologia Pediatrica e Cure Domiciliari, Azienda Ospedaliero-Universitaria Meyer, Viale Pieraccini, 24, 50139 Florence, Italy
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Familial hemophagocytic lymphohistiocytosis type 3 (FHL3) caused by deep intronic mutation and inversion in UNC13D. Blood 2011; 118:5783-93. [DOI: 10.1182/blood-2011-07-369090] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is an autosomal recessive, often-fatal hyperinflammatory disorder. Mutations in PRF1, UNC13D, STX11, and STXBP2 are causative of FHL2, 3, 4, and 5, respectively. In a majority of suspected FHL patients from Northern Europe, sequencing of exons and splice sites of such genes required for lymphocyte cytotoxicity revealed no or only monoallelic UNC13D mutations. Here, in 21 patients, we describe 2 pathogenic, noncoding aberrations of UNC13D. The first is a point mutation localized in an evolutionarily conserved region of intron 1. This mutation selectively impairs UNC13D transcription in lymphocytes, abolishing Munc13-4 expression. The second is a 253-kb inversion straddling UNC13D, affecting the 3′-end of the transcript and likewise abolishing Munc13-4 expression. Carriership of the intron 1 mutation was found in patients across Europe, whereas carriership of the inversion was limited to Northern Europe. Notably, the latter aberration represents the first description of an autosomal recessive human disease caused by an inversion. These findings implicate an intronic sequence in cell-type specific expression of Munc13-4 and signify variations outside exons and splice sites as a common cause of FHL3. Based on these data, we propose a strategy for targeted sequencing of evolutionary conserved noncoding regions for the diagnosis of primary immunodeficiencies.
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Sieni E, Cetica V, Santoro A, Beutel K, Mastrodicasa E, Meeths M, Ciambotti B, Brugnolo F, zur Stadt U, Pende D, Moretta L, Griffiths GM, Henter JI, Janka G, Aricò M. Genotype-phenotype study of familial haemophagocytic lymphohistiocytosis type 3. J Med Genet 2011; 48:343-52. [PMID: 21248318 DOI: 10.1136/jmg.2010.085456] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Mutations of UNC13D are causative for familial haemophagocytic lymphohistiocytosis type 3 (FHL3; OMIM 608898). OBJECTIVE To carry out a genotype-phenotype study of patients with FHL3. METHODS A consortium of three countries pooled data on presenting features and mutations from individual patients with biallelic UNC13D mutations in a common database. RESULTS 84 patients with FHL3 (median age 4.1 months) were reported from Florence, Italy (n=54), Hamburg, Germany (n=18), Stockholm, Sweden (n=12). Their ethnic origin was Caucasian (n=57), Turkish (n=10), Asian (n=7), Hispanic (n=4), African (n=3) (not reported (n=3)). Thrombocytopenia was present in 94%, splenomegaly in 96%, fever in 89%. The central nervous system (CNS) was involved in 49/81 (60%) patients versus 36% in patients with FHL2 (p=0.001). A combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia was present in 71%. CD107a expression, NK activity and Munc 13-4 protein expression were absent or reduced in all but one of the evaluated patients. 54 different mutations were observed, including 15 new ones: 19 missense, 14 deletions or insertions, 12 nonsense, nine splice errors. None was specific for ethnic groups. Patients with two disruptive mutations were younger than patients with two missense mutations (p<0.001), but older than comparable patients with FHL2 (p=0.001). CONCLUSION UNC13D mutations are scattered over the gene. Ethnic-specific mutations were not identified. CNS involvement is more common than in FHL2; in patients with FHL3 and disruptive mutations, age at diagnosis is significantly higher than in FHL2. The combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia appears to be the most easily and frequently recognised clinical pattern and their association with defective granule release assay may herald FHL3.
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Affiliation(s)
- Elena Sieni
- Department of Pediatric Hematology and Oncology, Azienda Ospedaliero-Universitaria Meyer, Florence, Italy
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Cetica V, Pende D, Griffiths GM, Aricò M. Molecular basis of familial hemophagocytic lymphohistiocytosis. Haematologica 2010; 95:538-41. [PMID: 20378576 DOI: 10.3324/haematol.2009.019562] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Yoon HS, Kim HJ, Yoo KH, Sung KW, Koo HH, Kang HJ, Shin HY, Ahn HS, Kim JY, Lim YT, Bae KW, Lee KO, Shin JS, Lee ST, Chung HS, Kim SH, Park CJ, Chi HS, Im HJ, Seo JJ. UNC13D is the predominant causative gene with recurrent splicing mutations in Korean patients with familial hemophagocytic lymphohistiocytosis. Haematologica 2009; 95:622-6. [PMID: 20015888 DOI: 10.3324/haematol.2009.016949] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Familial hemophagocytic lymphohistiocytosis is a fatal disease characterized by immune dysregulation from defective function of cytotoxic lymphocytes. Three causative genes have been identified for this autosomal recessive disorder (PRF1, UNC13D, and STX11). We investigated the molecular genetics of familial hemophagocytic lymphohistiocytosis in Korea. DESIGN AND METHODS Pediatric patients who fulfilled the HLH-2004 criteria were recruited from the Korean Registry for Histiocytosis. Molecular genetic studies were performed on the patients' DNA samples by direct sequencing of all coding exons and flanking sequences of PRF1, UNC13D, and STX11. RESULTS Forty patients were studied and familial hemophagocytic lymphohistiocytosis mutations were identified in nine; eight patients had UNC13D mutations (89%) and one had a mutation in PRF1. No patient had a STX11 mutation. Notably, four patients had only one UNC13D mutant allele, suggesting that the other mutation was missed by conventional direct sequencing. All UNC13D mutations were deleterious in nature. One known splicing mutation, c.754-1G>C, was recurrent, accounting for 58% of all the mutant alleles (7/12). Five UNC13D mutations were novel (p.Gln98X, p.Glu565SerfsX7, c.1993-2A>G, c.2367+1G>A, and c.2954+5G>A). The one patient with PRF1 mutation was homozygous for a frameshift mutation (p.Leu364GlufsX93), which was previously reported to be the most frequent PRF1 mutation in Japan. CONCLUSIONS This is the first investigation on the molecular genetics of familial hemophagocytic lymphohistiocytosis in Korea. The data showed that UNC13D is the predominant causative gene in the Korean population. The identification of mutations missed by conventional sequencing would better delineate the mutation spectrum and help to establish the optimal molecular diagnostic strategy for familial hemophagocytic lymphohistiocytosis in Korea, which might need an RNA-based screening strategy.
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Affiliation(s)
- Hoi Soo Yoon
- Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, Korea
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Current World Literature. Curr Opin Allergy Clin Immunol 2009; 9:574-8. [DOI: 10.1097/aci.0b013e328333c13c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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