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Carrillo-Tapia E, Espinosa-Padilla SE, Perez-Perez D, Gonzalez-Serrano ME, Berron-Ruiz L, Espinosa-Rosales FJ, Rodriguez-Alba JC, Mújica-Guzman F, Yokoyama-Rebollar E, García-Flores JR, Herrera-González NE, Scheffler-Mendoza S, Yamazaki-Nakashimada MA, Staines-Boone AT, Lopez-Herrera G. Improved HUMARA for the Detection of X-Linked Agammaglobulinemia Carriers. Genet Test Mol Biomarkers 2022; 26:220-227. [PMID: 35394812 DOI: 10.1089/gtmb.2021.0139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a polymerase chain reaction (PCR)-based method for detecting X-linked agammaglobulinemia (XLA) carriers. This method takes advantage of X-chromosome inactivation (XCI) in female cells. XLA is caused by mutations in the Bruton tyrosine kinase (BTK) gene, located in Xq22.1. In this study, XCI is nonrandom or skewed in B cells. B cells with an active X-chromosome carrying a BTK mutation do not mature. Peripheral B cells in XLA carriers inactivate the mutated X-chromosome. Methods: HUMARA was performed using DNA from purified B cells and total leukocytes. DNA was digested using methylation-sensitive HhaI. The PCR of the HUMARA polymorphic marker was performed with the HhaI digested samples. The lengths of the PCR product were determined. If a suspected carrier showed skewed XCI in B cells, the marker length that corresponded with the length determined in the index patient indicated their carrier status. Results: HUMARA was conducted on purified B cells; this allowed easier identification of the mutated or inactive allele, as the active allele was enzymatically digested. Analysis of 30 possible carriers using modified HUMARA corroborated that the carrier status in all samples that were heterozygous for the marker using XCI calculation for leukocytes showed a Gaussian distribution, while the carrier B cell DNA showed a skewed XCI. Conclusion: Carrier status was successfully determined for most of the analyzed samples. B cell enrichment resulted in precise carrier determination data, reduced the sample size, and facilitated inactive and active allele identification.
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Affiliation(s)
| | - Sara E Espinosa-Padilla
- Laboratorio de Inmunodeficiencias, Instituto Nacional de Pediatría, Ciudad de México, México
| | - Daniela Perez-Perez
- Laboratorio de Inmunodeficiencias, Instituto Nacional de Pediatría, Ciudad de México, México.,Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | | | - Laura Berron-Ruiz
- Laboratorio de Inmunodeficiencias, Instituto Nacional de Pediatría, Ciudad de México, México
| | | | | | - Fabiola Mújica-Guzman
- Laboratorio de Hematología, Instituto Nacional de Pediatría, Ciudad de México, México
| | | | - Jose R García-Flores
- Posgrado en Ciencias de la Salud, Escuela Superior de Medicina, Ciudad de México, México
| | | | | | | | | | - Gabriela Lopez-Herrera
- Laboratorio de Inmunodeficiencias, Instituto Nacional de Pediatría, Ciudad de México, México
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2
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Magini P, Poscente M, Ferrari S, Vargiolu M, Bacchelli E, Graziano C, Wischmeijer A, Turchetti D, Malaspina E, Marchiani V, Cordelli DM, Franzoni E, Romeo G, Seri M. Cytogenetic and molecular characterization of a recombinant X chromosome in a family with a severe neurologic phenotype and macular degeneration. Mol Cytogenet 2015; 8:58. [PMID: 26236399 PMCID: PMC4522089 DOI: 10.1186/s13039-015-0164-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/15/2015] [Indexed: 11/13/2022] Open
Abstract
Background Duplications of MECP2 gene in males cause a syndrome characterized by distinctive clinical features, including severe to profound mental retardation, infantile hypotonia, mild dysmorphic features, poor speech development, autistic features, seizures, progressive spasticity and recurrent infections. Patients with complex chromosome rearrangements, leading to Xq28 duplication, share most of the clinical features of individuals with tandem duplications, in particular neurologic problems, suggesting a major pathogenetic role of MECP2 overexpression. Results We performed cytogenetic and molecular cytogenetic studies in a previously described family with affected males showing congenital ataxia, late-onset progressive myoclonic encephalopathy and selective macular degeneration. Microsatellite, FISH and array-CGH analyses identified a recombinant X chromosome with a deletion of the PAR1 region, encompassing SHOX, replaced by a duplicated segment of the Xq28 terminal portion, including MECP2. Conclusions Our report describes the identification of the actual genetic cause underlying a severe syndrome that previous preliminary analyses erroneously associated to a terminal Xp22.33 region. In the present family as well as in previously reported patients with similar rearrangements, the observed neurologic phenotype is ascribable to MECP2 duplication, with an undefined contribution of the other involved genes. Maculopathy, presented by affected males reported here, could be a novel clinical feature associated to Xq28 disomy due to recombinant X chromosomes, but at present the underlying pathogenetic mechanism is unknown and this potential clinical correlation should be confirmed through the collection of additional patients.
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Affiliation(s)
- Pamela Magini
- U.O. Genetica Medica, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, via Massarenti, 9, Bologna, 40138 Italy
| | - Monica Poscente
- S.S.V.D. Biologia Molecolare, Citogenetica, Citomorfologia Ematica e Vaginale, Ospedale Belcolle, Viterbo, Italy
| | - Simona Ferrari
- U.O. Genetica Medica, AOU di Bologna, Policlinico S. Orsola-Malpighi, Bologna, 40138 Italy
| | - Manuela Vargiolu
- Centro Interdipartimentale per la Ricerca Industriale Scienze della Vita e Tecnologie per la Salute, Università di Bologna, Bologna, Italy
| | - Elena Bacchelli
- Dipartimento di Farmacia e Biotecnologie, Università di Bologna, Bologna, Italy
| | - Claudio Graziano
- U.O. Genetica Medica, AOU di Bologna, Policlinico S. Orsola-Malpighi, Bologna, 40138 Italy
| | - Anita Wischmeijer
- U.O. Genetica Medica, AOU di Bologna, Policlinico S. Orsola-Malpighi, Bologna, 40138 Italy.,S.S.D. Genetica Clinica, Arcispedale S. Maria Nuova-Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia, Italy
| | - Daniela Turchetti
- U.O. Genetica Medica, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, via Massarenti, 9, Bologna, 40138 Italy
| | - Elisabetta Malaspina
- U.O. Neuropsichiatria Infantile, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, Bologna, Italy
| | - Valentina Marchiani
- U.O. Neuropsichiatria Infantile, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, Bologna, Italy
| | - Duccio Maria Cordelli
- U.O. Neuropsichiatria Infantile, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, Bologna, Italy
| | - Emilio Franzoni
- U.O. Neuropsichiatria Infantile, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, Bologna, Italy
| | - Giovanni Romeo
- U.O. Genetica Medica, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, via Massarenti, 9, Bologna, 40138 Italy
| | - Marco Seri
- U.O. Genetica Medica, Policlinico Sant'Orsola-Malpighi, DIMEC, Università di Bologna, via Massarenti, 9, Bologna, 40138 Italy
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3
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A female patient with incomplete hemophagocytic lymphohistiocytosis caused by a heterozygous XIAP mutation associated with non-random X-chromosome inactivation skewed towards the wild-type XIAP allele. J Clin Immunol 2015; 35:244-8. [PMID: 25744037 DOI: 10.1007/s10875-015-0144-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 02/13/2015] [Indexed: 10/23/2022]
Abstract
X-linked lymphoproliferative disease (XLP) is a rare inherited immunodeficiency that often leads to hemophagocytic lymphohistiocytosis (HLH). XLP can be classified as XLP1 or XLP2, caused by mutations in SH2D1A and XIAP, respectively. In women, X-chromosome inactivation (XCI) of most X-linked genes occurs on one of the X chromosomes in each cell. The choice of which X chromosome remains activated is generally random, although genetic differences and selective advantage may cause one of the X chromosomes to be preferentially inactivated. Here we describe three patients with pancytopenia, including one female patient, in a Japanese family with a novel XIAP mutation. All three patients exhibited deficient XIAP protein expression, impaired NOD2/XIAP signaling, and augmented activation-induced cell death. In the female patient, the paternally derived X chromosome was non-randomly and exclusively inactivated in her peripheral blood and hair root cells. In contrast to asymptomatic females, this patient exhibied non-random XCI skewed towards the wild-type XIAP allele. This is the first report of a female patient with incomplete HLH resulting from a heterozygous XIAP mutation in association with non-random XCI.
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4
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Takimoto T, Takada H, Ishimura M, Kirino M, Hata K, Ohara O, Morio T, Hara T. Wiskott-Aldrich syndrome in a girl caused by heterozygous WASP mutation and extremely skewed X-chromosome inactivation: a novel association with maternal uniparental isodisomy 6. Neonatology 2015; 107:185-90. [PMID: 25633059 DOI: 10.1159/000370059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/24/2014] [Indexed: 11/19/2022]
Abstract
Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema and immune deficiency, caused primarily by mutations in the WASP (Wiskott-Aldrich syndrome protein) gene. Female carriers are usually asymptomatic because of the preferential activation of the normal, nonmutated X-chromosome in their hematopoietic cells. We report our observations of a female child with WAS, who displayed symptoms of congenital thrombocytopenia. DNA sequencing analysis of the WASP gene revealed a heterozygous nonsense mutation in exon 10. The expressions of WASP and normal WASP mRNA were defective. We found preferential inactivation of the X-chromosome on which wild-type WASP was located. Single-nucleotide polymorphism microarray testing and the analysis of the polymorphic variable number of tandem repeat regions revealed maternal uniparental isodisomy of chromosome 6 (UPD6). Our results underscore the importance of WASP evaluation in females with congenital thrombocytopenia and suggest that UPD6 might be related to the pathophysiology of nonrandom X-chromosome inactivation.
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Affiliation(s)
- Tomohito Takimoto
- Departments of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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5
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Liao SL, Lai SH, Huang JL, Lee NC, Lee WI. Serial cytokine expressions in infants with incontinentia pigmenti. Immunobiology 2012; 218:772-9. [PMID: 23079196 DOI: 10.1016/j.imbio.2012.08.280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 08/26/2012] [Indexed: 11/18/2022]
Abstract
NF-κB dysfunction resulting from NEMO (NF-kappaB essential modulator) mutation can lead to significant alterations in cytokine production. However, little is known about changes in the expression of downstream molecules in patients with incontinentia pigmenti (IP). We aim to investigate serial cytokine expressions during the first 2 years of life in young infants with IP, the period in which skin inflammation and morphological changes are most significant. Gene analysis and X-inactivation test were performed for the two neonates with IP. Peripheral mononuclear cells were obtained after birth and successively at 6-month interval up to the age of two years. Levels of TNF-α and IL-6 were analyzed with ELISA before and after stimulating with Toll-like receptor ligands. The result showed the male IP patient had normal NEMO allele. His cytokine level, although initially lower, had returned to a level comparable with those of controls at 12 months of age. The female infant had mutated NEMO gene. Her baseline TNF-α level was significantly higher than those of the control subjects at birth and remained high by 6 months of age. All cytokine responses had decreased significantly by 2 years of age, the time in which all vesicular skin lesions had resolved. Both infants had normal serum immunoglobulin level and remained infection free during the follow up period. To our knowledge, this is the first report that demonstrates serial changes of cytokine profiles in humans with IP. This study showed that in the presence of NEMO mutation, alteration of cytokine production was remarkable during the first year of life, which may account for the prominent inflammatory changes in skin morphology.
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Affiliation(s)
- Sui-Ling Liao
- Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Taiwan
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6
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Loss of MAGT1 abrogates the Mg2+ flux required for T cell signaling and leads to a novel human primary immunodeficiency. MAGNESIUM RESEARCH 2012; 24:S109-14. [PMID: 21983175 DOI: 10.1684/mrh.2011.0286] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although Mg(2+) has a well-recognized role as an essential cofactor for all ATP-binding enzymes, its role as a signaling ion, like Ca(2+), has been controversial. A requirement for Mg(2+)for optimal T lymphocyte stimulation was demonstrated more than 30 years ago, but the mechanism of its synergistic effect with Ca(2+)in T cell activation remains elusive. Here, we summarize our recent discovery of a signaling role for Mg(2+)in the T cell antigen receptor (TCR) signaling pathway from the study of a novel primary immunodeficiency, now named X-linked immunodeficiency with Mg(2+)defect, EBV infection and neoplasia (XMEN). XMEN patients were found to have a deficiency in magnesium transporter 1 (MAGT1), an Mg(2+)-specific transporter, which leads to the absence of a TCR-stimulated Mg(2+)flux and an attenuation of T cell activation. We further showed that this Mg(2+)flux is required proximally for the temporal orchestration of phospholipase C-γ1 (PLCγ1) activation. Thus, our study not only provides a second messenger role for Mg(2+)to explain its synergism with calcium in T cell signaling, it also identifies a potential extracellular therapeutic target for T cell-specific immunomodulation.
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7
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Li FY, Chaigne-Delalande B, Kanellopoulou C, Davis JC, Matthews HF, Douek DC, Cohen JI, Uzel G, Su HC, Lenardo MJ. Second messenger role for Mg2+ revealed by human T-cell immunodeficiency. Nature 2011; 475:471-6. [PMID: 21796205 PMCID: PMC3159560 DOI: 10.1038/nature10246] [Citation(s) in RCA: 372] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/03/2011] [Indexed: 01/18/2023]
Abstract
The magnesium ion, Mg(2+), is essential for all life as a cofactor for ATP, polyphosphates such as DNA and RNA, and metabolic enzymes, but whether it plays a part in intracellular signalling (as Ca(2+) does) is unknown. Here we identify mutations in the magnesium transporter gene, MAGT1, in a novel X-linked human immunodeficiency characterized by CD4 lymphopenia, severe chronic viral infections, and defective T-lymphocyte activation. We demonstrate that a rapid transient Mg(2+) influx is induced by antigen receptor stimulation in normal T cells and by growth factor stimulation in non-lymphoid cells. MAGT1 deficiency abrogates the Mg(2+) influx, leading to impaired responses to antigen receptor engagement, including defective activation of phospholipase Cγ1 and a markedly impaired Ca(2+) influx in T cells but not B cells. These observations reveal a role for Mg(2+) as an intracellular second messenger coupling cell-surface receptor activation to intracellular effectors and identify MAGT1 as a possible target for novel therapeutics.
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Affiliation(s)
- Feng-Yen Li
- Molecular Development Section, Lymphocyte Molecular Genetics Unit, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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8
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Making a definitive diagnosis: successful clinical application of whole exome sequencing in a child with intractable inflammatory bowel disease. Genet Med 2011; 13:255-62. [PMID: 21173700 DOI: 10.1097/gim.0b013e3182088158] [Citation(s) in RCA: 510] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE We report a male child who presented at 15 months with perianal abscesses and proctitis, progressing to transmural pancolitis with colocutaneous fistulae, consistent with a Crohn disease-like illness. The age and severity of the presentation suggested an underlying immune defect; however, despite comprehensive clinical evaluation, we were unable to arrive at a definitive diagnosis, thereby restricting clinical management. METHODS We sought to identify the causative mutation(s) through exome sequencing to provide the necessary additional information required for clinical management. RESULTS After sequencing, we identified 16,124 variants. Subsequent analysis identified a novel, hemizygous missense mutation in the X-linked inhibitor of apoptosis gene, substituting a tyrosine for a highly conserved and functionally important cysteine. X-linked inhibitor of apoptosis was not previously associated with Crohn disease but has a central role in the proinflammatory response and bacterial sensing through the NOD signaling pathway. The mutation was confirmed by Sanger sequencing in a licensed clinical laboratory. Functional assays demonstrated an increased susceptibility to activation-induced cell death and defective responsiveness to NOD2 ligands, consistent with loss of normal X-linked inhibitor of apoptosis protein function in apoptosis and NOD2 signaling. CONCLUSIONS Based on this medical history, genetic and functional data, the child was diagnosed as having an X-linked inhibitor of apoptosis deficiency. Based on this finding, an allogeneic hematopoietic progenitor cell transplant was performed to prevent the development of life-threatening hemophagocytic lymphohistiocytosis, in concordance with the recommended treatment for X-linked inhibitor of apoptosis deficiency. At >42 days posttransplant, the child was able to eat and drink, and there has been no recurrence of gastrointestinal disease, suggesting this mutation also drove the gastrointestinal disease. This report describes the identification of a novel cause of inflammatory bowel disease. Equally importantly, it demonstrates the power of exome sequencing to render a molecular diagnosis in an individual patient in the setting of a novel disease, after all standard diagnoses were exhausted, and illustrates how this technology can be used in a clinical setting.
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Wild-type FOXP3 is selectively active in CD4+CD25(hi) regulatory T cells of healthy female carriers of different FOXP3 mutations. Blood 2009; 114:4138-41. [PMID: 19738030 DOI: 10.1182/blood-2009-04-214593] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Forkhead box P3 (FOXP3) is constitutively expressed by CD4(+)CD25(hi) regulatory T cells (nTregs). Mutations of FOXP3 cause a severe autoimmune syndrome known as immune dysregulation polyendocrinopathy enteropathy X-linked, in which nTregs are absent or dysfunctional. Whether FOXP3 is essential for both differentiation and function of human nTreg cells remains to be demonstrated. Because FOXP3 is an X-linked gene subject to X-chromosome inactivation (XCI), we studied 9 healthy female carriers of FOXP3 mutations to investigate the role of wild-type (WT) versus mutated FOXP3 in different cell subsets. Analysis of active WT versus mutated (mut)-FOXP3 allele distribution revealed a random pattern of XCI in peripheral blood lymphocytes and in naive and memory CD4(+)T cells, whereas nTregs expressed only the active WT-FOXP3. These data demonstrate that expression of WT-FOXP3 is indispensable for the presence of a normal nTreg compartment and suggest that FOXP3 is not necessary for effector T-cell differentiation in humans.
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10
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Skewed X chromosome inactivation and trisomic spontaneous abortion: no association. Am J Hum Genet 2009; 85:179-93. [PMID: 19646676 DOI: 10.1016/j.ajhg.2009.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 06/29/2009] [Accepted: 07/01/2009] [Indexed: 11/21/2022] Open
Abstract
Several studies suggest that highly skewed X chromosome inactivation (HSXI) is associated with recurrent spontaneous abortion. We hypothesized that this association reflects an increased rate of trisomic conceptions due to anomalies on the X chromosome that lead both to HSXI and to a diminished oocyte pool. We compared the distribution of X chromosome inactivation (XCI) skewing percentages (range: 50%-100%) among women with spontaneous abortions in four karyotype groups-trisomy (n = 154), chromosomally normal male (n = 43), chromosomally normal female (n = 38), nontrisomic chromosomally abnormal (n = 61)-to the distribution for age-matched controls with chromosomally normal births (n = 388). In secondary analyses, we subdivided the nontrisomic chromosomally abnormal group, divided trisomies by chromosome, and classified women by reproductive history. Our data support neither an association of HSXI with all trisomies nor an association of HSXI with chromosomally normal male spontaneous abortions. We also find no association between HSXI and recurrent abortion (n = 45).
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Woon ST, Ameratunga R, Croxson M, Taylor G, Neas K, Edkins E, Browett P, Gane E, Munn S. Follicular lymphoma in a X-linked lymphoproliferative syndrome carrier female. Scand J Immunol 2008; 68:153-8. [PMID: 18702745 DOI: 10.1111/j.1365-3083.2008.02128.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
X-linked lymphoproliferative (XLP) syndrome is a rare primary immune-deficiency disorder caused by mutations of the SH2D1A or XIAP genes. Males with the disorder are usually in good health until contracting Epstein-Barr virus (EBV) whereupon the majority of patients die from fulminant infectious mononucleosis, lymphoma or hypogammaglobulinaemia. This report describes a female carrier with an XLP phenotype who was retrospectively identified after her grandson died from the disorder. Subsequent genetic testing identified the patient's mother and affected maternal grandmother as XLP carriers. The family's medical records were significant. The proband had lymphoma at ages 2 and 8 and made a full recovery following treatment. Both the maternal grandmother and uncle died of non-Hodgkin's lymphoma. We were concerned that the XLP carrier mother may be predisposed to lymphoma if the normal X chromosome is skewed towards inactivation. The human androgen receptor assay detected random X chromosome inactivation in the carrier mother. EBV was not detected in the lymphoma tissues of the proband and his grandmother, confirming previous findings that EBV is not always associated with lymphoma in XLP. More significantly, our study highlights the importance of identifying XLP in families with a high incidence of lymphoma.
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Affiliation(s)
- S-T Woon
- Department of Virology, LabPLUS, Auckland City Hospital, Auckland, New Zealand
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12
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Weinhaeusel A, Thiele S, Hofner M, Hiort O, Noehammer C. PCR-based analysis of differentially methylated regions of GNAS enables convenient diagnostic testing of pseudohypoparathyroidism type Ib. Clin Chem 2008; 54:1537-45. [PMID: 18617581 DOI: 10.1373/clinchem.2008.104216] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Pseudohypoparathyroidism type Ib (PHPIb) is characterized by parathyroid hormone (PTH) resistance, which can lead to hypocalcemia, hyperphosphatemia, and increased serum PTH. The disorder is caused by mutations in regulatory regions of the GNAS gene (GNAS complex locus) that lead to interferences in the methylation status of alternative GNAS promoters, such as exon A/B, NESP55, and XL alpha-s. PHPIb comprises disorders that show distinctive changes in methylation status but share the same clinical phenotype: (a) loss of methylation only at exon A/B of the GNAS gene and involving no other obvious epigenetic abnormalities [e.g., those caused by heterozygous microdeletions in the STX16 (syntaxin 16) region and found in many patients with autosomal dominant (AD) PHPIb]; (b) methylation abnormalities at several differentially methylated regions (DMRs), which are observed in most patients with sporadic PHPIb and some families with AD PHPIb. METHODS To permit early and reliable diagnosis of suspected PHPIb, we designed methylation-sensitive restriction enzyme-based and bisulfite deamination-based PCR tests for exon A/B and NESP55 DMRs. RESULTS Both PCR strategies permit proper methylation testing of GNAS and NESP55 DMRs and elucidate different disease subtypes. We have identified a novel microsatellite repeat polymorphism within GNAS exon A/B, and pedigree analyses have shown its presence to be conclusive evidence for familial disease. CONCLUSIONS We provide a simple diagnostic test for PHPIb, an imprinting disorder caused by different molecular changes within the GNAS complex locus. PHPIb, a complex and diagnostically challenging clinical phenotype, can be treated successfully by taking steps before the manifestation of symptoms to avoid clinical complications in affected patients or asymptomatic members of affected families who show positive results in genetic tests.
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Affiliation(s)
- Andreas Weinhaeusel
- Austrian Research Centers GmbH-ARC, Molecular Diagnostics, Seibersdorf, Austria.
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13
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Nichols KE, Hom J, Gong SY, Ganguly A, Ma CS, Cannons JL, Tangye SG, Schwartzberg PL, Koretzky GA, Stein PL. Regulation of NKT cell development by SAP, the protein defective in XLP. Nat Med 2005; 11:340-5. [PMID: 15711562 PMCID: PMC10655637 DOI: 10.1038/nm1189] [Citation(s) in RCA: 295] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Accepted: 01/07/2005] [Indexed: 11/09/2022]
Abstract
The adaptor molecule SAP is expressed in T lymphocytes and natural killer (NK) cells, where it regulates cytokine production and cytotoxicity. Here, we show that SAP, encoded by the SH2D1A gene locus, also has a crucial role during the development of NKT cells, a lymphocyte subset with immunoregulatory functions in response to infection, cancer and autoimmune disease. Following stimulation with the NKT cell-specific agonist alpha-galactosyl ceramide (alphaGC), Sh2d1a-/- splenocytes did not produce cytokines or activate other lymphoid lineages in an NKT cell-dependent manner. While evaluating the abnormalities in alphaGC-induced immune responses, we observed that Sh2d1a-/- animals lacked NKT cells in the thymus and peripheral organs. The defect in NKT cell ontogeny was hematopoietic cell autonomous and could be rescued by reconstitution of SAP expression within Sh2d1a-/- bone marrow cells. Seventeen individuals with X-linked lymphoproliferative disease (XLP), who harbored germline mutations in SH2D1A, also lacked NKT cells. Furthermore, a female XLP carrier showed completely skewed X chromosome inactivation within NKT cells, but not T or B cells. Thus, SAP is a crucial regulator of NKT cell ontogeny in humans and in mice. The absence of NKT cells may contribute to the phenotypes of SAP deficiency, including abnormal antiviral and antitumor immunity and hypogammaglobulinemia.
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Affiliation(s)
- Kim E Nichols
- Pediatric Oncology, Wood, 4th floor, 3615 Civic Center Boulevard, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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Owen CJ, Jennings CE, Imrie H, Lachaux A, Bridges NA, Cheetham TD, Pearce SHS. Mutational analysis of the FOXP3 gene and evidence for genetic heterogeneity in the immunodysregulation, polyendocrinopathy, enteropathy syndrome. J Clin Endocrinol Metab 2003; 88:6034-9. [PMID: 14671208 DOI: 10.1210/jc.2003-031080] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The immunodysregulation, polyendocrinopathy, enteropathy syndrome (IPEX), is a rare disorder of immune regulation resulting in multiple autoimmune disorders, which demonstrates X-linked recessive inheritance. The disease gene, FOXP3, was identified in 2001, and several mutations within this gene have since been described in patients with IPEX. We used linkage analysis, mutational screening of the FOXP3 gene, human leukocyte antigen typing, and analysis of X-chromosome inactivation to investigate 2 kindreds (21 subjects in total) with 4 male infants (3 now deceased) and 1 girl affected by IPEX. In 1 family a novel FOXP3 mutation was identified in the proband, with a single base deletion at codon 76 of exon 2, leading to a frameshift, which predicted a truncated protein product (108 residues vs. 431 in wild type). In the second family, the FOXP3 locus was excluded by recombination, and mutational analysis of the gene was negative. The affected girl from this family was shown to have human leukocyte antigen DR2 and DR6 alleles and random X-chromosome inactivation in peripheral blood mononuclear cells. Our analysis has elucidated the molecular basis of IPEX in one family and has, for the first time, provided evidence for an autosomal locus, suggesting genetic heterogeneity in this syndrome.
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Affiliation(s)
- Catherine J Owen
- Institute of Human Genetics and Department of Child Health, University of Newcastle upon Tyne, United Kingdom.
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15
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Tommasini A, Ferrari S, Moratto D, Badolato R, Boniotto M, Pirulli D, Notarangelo LD, Andolina M. X-chromosome inactivation analysis in a female carrier of FOXP3 mutation. Clin Exp Immunol 2002; 130:127-30. [PMID: 12296863 PMCID: PMC1906506 DOI: 10.1046/j.1365-2249.2002.01940.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immune dysregulation, polyendocrinopathy and enteropathy with X-linked inheritance (IPEX) is a serious disease arising from mutations in FOXP3. This gene codifies for a transcription factor whose dysfunction results in hyperactivation of T cells. It is not clear, however, why an intermediate phenotype is not seen in heterozygous females, who are completely healthy. In order to address this question, we investigated X-chromosome inactivation in peripheral blood lymphocytes from a heterozygous female with a child affected by IPEX. No preferential inactivation was shown in freshly sorted CD4+, CD8+, CD19+ cells or in IL-2 cultured CD4 and CD8 T cells, indicating that peripheral blood lymphocytes in these women are randomly selected. Moreover, only one single FOXP3 transcript was expressed by CD4 T cell clones analysed by RT-PCR, confirming that this gene is subject to X- inactivation. We hypothesize that hyper-activation of T cell in carriers of FOXP3 mutations is regulated by the presence of normal regulatory T cells.
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Affiliation(s)
- A Tommasini
- Department of Sciences of Reproduction and Development IRCCS Burlo Garofolo, Trieste, Italy.
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16
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Inoue H, Kurosawa H, Nonoyama S, Imai K, Kumazaki H, Matsunaga T, Sato Y, Sugita K, Eguchi M. X-linked thrombocytopenia in a girl. Br J Haematol 2002; 118:1163-5. [PMID: 12199801 DOI: 10.1046/j.1365-2141.2002.03740.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report X-linked thrombocytopenia (XLT) in a 6-year-old girl with petechiae and thrombocytopenia from the age of 3 months. Her 2-year-old brother was also diagnosed with XLT. The Wiskott-Aldrich syndrome protein (WASP) gene was detected as a replacement of +5th G to Aon intron 6 using sequence analysis, and the WASP expression levels in this patient were one-third those of a healthy control. The X-inactivation analysis of the patients lymphocytes showed a random pattern of X-chromosome inactivation. To our knowledge, this is the first confirmed report of XLT in a female.
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Affiliation(s)
- Hirokazu Inoue
- Division of Haematology, Department of Paediatrics, Dokkyo University School of Medicine, Tochigi, Japan
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17
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Pilz DT, Kuc J, Matsumoto N, Bodurtha J, Bernadi B, Tassinari CA, Dobyns WB, Ledbetter DH. Subcortical band heterotopia in rare affected males can be caused by missense mutations in DCX (XLIS) or LIS1. Hum Mol Genet 1999; 8:1757-60. [PMID: 10441340 DOI: 10.1093/hmg/8.9.1757] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Subcortical band heterotopia (SBH) are bilateral and symmetric ribbons of gray matter found in the central white matter between the cortex and the ventricular surface, which comprises the less severe end of the lissencephaly (agyria-pachygyria-band) spectrum of malformations. Mutations in DCX (also known as XLIS ) have previously been described in females with SBH. We have now identified mutations in either the DCX or LIS1 gene in three of 11 boys studied, demonstrating for the first time that mutations of either DCX or LIS1 can cause SBH or mixed pachygyria-SBH (PCH-SBH) in males. All three changes detected are missense mutations, predicted to be of germline origin. They include a missense mutation in exon 4 of DCX in a boy with PCH-SBH (R78H), a different missense mutation in exon 4 of DCX in a boy with mild SBH and in his mildly affected mother (R89G) and a missense mutation in exon 6 of LIS1 in a boy with SBH (S169P). The missense mutations probably account for the less severe brain malformations, although other patients with missense mutations in the same exons have had diffuse lissencephaly. Therefore, it appears likely that the effect of the specific amino acid change on the protein determines the severity of the phenotype, with some mutations enabling residual protein function and allowing normal migration in a larger proportion of neurons. However, we expect that somatic mosaic mutations of both LIS1 and DCX will also prove to be an important mechanism in causing SBH in males.
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Affiliation(s)
- D T Pilz
- Institute for Medical Genetics, University Hospital of Wales, Cardiff CF4 4XW, UK
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18
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Shastry BS, Hiraoka M, Trese DC, Trese MT. Norrie disease and exudative vitreoretinopathy in families with affected female carriers. Eur J Ophthalmol 1999; 9:238-42. [PMID: 10544980 DOI: 10.1177/112067219900900312] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Norrie disease (ND) is a rare X-linked recessive disorder characterized by congenital blindness, which is often associated with sensorineural hearing loss and mental retardation. X-linked familial exudative vitreoretinopathy (FEVR) is a hereditary disorder characterized by an abnormality of the peripheral retina and is not associated with systemic diseases. X-linked recessive disorders generally do not affect females. Here we show that female carriers can be associated with manifestation of an X-linked disorder. METHODS A four-generation family with an affected female, and a history of congenital blindness and hearing loss, was identified through the pro-band. A second family, with a full-term female infant, was evaluated through ophthalmic examinations and found to exhibit ocular features, such as retinal folds, retinal detachment and peripheral exudates. Peripheral blood specimens were collected from several affected and unaffected family members. DNA was extracted and analyzed by single-strand conformation polymorphism (SSCP) following polymerase chain reaction (PCR) amplification of the exons of the Norrie disease gene. The amplified products were sequenced by the dideoxy chain termination method. RESULTS In an X-linked four-generation family, a novel missense (A118D) mutation in the third exon of the Norrie disease gene, was identified. The mutation was transmitted through three generations and cosegregated with the disease. The affected maternal grandmother and the unaffected mother carried the same mutation in one of their alleles. In an unrelated sporadic family, a heterozygous missense mutation (C96Y) was identified in the third exon of the Norrie disease gene in an affected individual. Analysis of exon-1 and 2 of the Norrie disease gene did not reveal any additional sequence alterations in these families. The mutations were not detected in the unaffected family members and the 116 normal unrelated controls, suggesting that they are likely to be the pathogenic mutations. CONCLUSIONS The results further strengthen the proposal that X-linked disorders can occur in female carriers, due likely to an unfavorable X-inactivation.
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Affiliation(s)
- B S Shastry
- Eye Research Institute, Oakland University, Rochester, MI 48309, USA
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19
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Kirchhausen T. Wiskott-Aldrich syndrome: a gene, a multifunctional protein and the beginnings of an explanation. MOLECULAR MEDICINE TODAY 1998; 4:300-4. [PMID: 9743991 DOI: 10.1016/s1357-4310(98)01268-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Patients with Wiskott-Aldrich syndrome show various defects in the normal function of platelets and lymphocytes. The recent identification of the gene responsible for this syndrome has led to a surge of studies aimed at solving the puzzle posed by the varied phenotype observed in this disease. It is now known that WASP, the protein product of this gene, can interact with a large number of other proteins known to be involved in the regulation of signal transduction and cytoskeletal organization. Thus, WASP appears to integrate these two basic and fundamental cellular mechanisms. Several groups are now focusing on understanding the function of WASP in detail, and translating this new knowledge into improved therapies.
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20
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Wengler GS, Giliani S, Fiorini M, Mella P, Mantuano E, Zanola A, Pollonini G, Eibl MM, Ugazio AG, Notarangelo LD, Parolini O. Mutation analysis by a non-radioactive single-strand conformation polymorphism assay in nine families with X-linked severe combined immunodeficiency (SCIDX1). Br J Haematol 1998; 101:586-91. [PMID: 9633906 DOI: 10.1046/j.1365-2141.1998.00721.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
X-linked severe combined immunodeficiency (SCIDX1) is an inherited disease characterized by profound abnormalities of cell-mediated and humoral immunity. Patients with SCIDX1 have defects in the common cytokine receptor gamma chain gene (IL2RG) that encodes a shared, essential component of the receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9 and IL-15. We have characterized nine SCIDX1 families by using a DNA-based, non-radioactive screening method and DNA sequencing. Nine different mutations were found, scattered from exon 1 to exon 5 of the IL2RG gene. Two of these mutations have been previously identified in other unrelated patients; the other seven are novel mutations that differ from all of the 95 already reported in the IL2RG mutation data base. In addition to describing novel mutations in the IL2RG gene, this study shows that the knowledge of the genetic defect and the use of an efficient, non-radioactive, and rapid screening approach have important implications for prenatal and postnatal diagnosis, carrier female identification, and possibly prenatal therapy.
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21
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Facchetti F, Blanzuoli L, Vermi W, Notarangelo LD, Giliani S, Fiorini M, Fasth A, Stewart DM, Nelson DL. Defective actin polymerization in EBV-transformed B-cell lines from patients with the Wiskott-Aldrich syndrome. J Pathol 1998; 185:99-107. [PMID: 9713366 DOI: 10.1002/(sici)1096-9896(199805)185:1<99::aid-path48>3.0.co;2-l] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive disorder characterized by eczema, thrombocytopenia, and immunodeficiency. An allelic variant of the disease is characterized by isolated thrombocytopenia (XLT). The gene responsible for WAS/XLT (WASP) encodes for a 502 amino acid protein (WASP) that is possibly involved in actin binding and cytoskeleton organization. The expression of WASP and the distribution of F-actin and alpha-actinin (which binds to and stabilizes actin filaments) have been analysed in lymphoblastoid cell lines from six patients with WAS and one with XLT. Western blot and immunocytochemistry did not reveal WASP expression in four WAS patients, whereas two WAS patients (with a moderate clinical course) expressed trace amounts of mutant WASP. In contrast, the XLT patient expressed normal amounts of WASP. Furthermore, cell lines from WAS and XLT patients also markedly differed in F-actin polymerization and alpha-actinin distribution. In particular, severe defects of cytoplasmic F-actin expression and of F-actin-positive microvillus formation, and impaired capping of alpha-actinin, were observed in all patients who lacked WASP. As a whole, the degree of impairment of WASP protein expression in WAS/XLT seems to correlate with anomalies of cytoskeletal organization, strongly supporting a role for WASP in the regulation of F-actin polymerization.
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Affiliation(s)
- F Facchetti
- Department of Pathology, University of Brescia, Italy
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22
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Parolini O, Ressmann G, Haas OA, Pawlowsky J, Gadner H, Knapp W, Holter W. X-linked Wiskott-Aldrich syndrome in a girl. N Engl J Med 1998; 338:291-5. [PMID: 9445409 DOI: 10.1056/nejm199801293380504] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- O Parolini
- Institute of Immunology-Vienna International Research Cooperation Center at Novartis Forschungsinstitut, University of Vienna, Austria
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