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Johnson MD, He L, Herman D, Wakimoto H, Wallace CA, Zidek V, Mlejnek P, Musilova A, Simakova M, Vorlicek J, Kren V, Viklicky O, Qi NR, Wang J, Seidman CE, Seidman J, Kurtz TW, Aitman TJ, Pravenec M. Dissection of chromosome 18 blood pressure and salt-sensitivity quantitative trait loci in the spontaneously hypertensive rat. Hypertension 2009; 54:639-45. [PMID: 19620519 PMCID: PMC4046892 DOI: 10.1161/hypertensionaha.108.126664] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hypertension in humans and experimental models has a strong hereditary basis, but identification of causative genes remains challenging. Quantitative trait loci (QTLs) for hypertension and salt sensitivity have been reported on rat chromosome 18. We set out to genetically isolate and prioritize genes within the salt-sensitivity and hypertension QTLs on the spontaneously hypertensive rat (SHR) chromosome 18 by developing and characterizing a series of congenic strains derived from the SHR and normotensive Brown Norway rat strains. The SHR.BN-D18Rat113/D18Rat82 congenic strain exhibits significantly lower blood pressure and is salt resistant compared with the SHR. Transplantation of kidneys from SHR.BN-D18Rat113/D18Rat82 donors into SHR recipients is sufficient to attenuate increased blood pressure but not salt sensitivity. Derivation of congenic sublines allowed for the separation of salt sensitivity from hypertension QTL regions. Renal expression studies with microarray and Solexa-based sequencing in parental and congenic strains identified 4 differentially expressed genes within the hypertension QTL region, one of which is an unannotated transcript encoding a previously undescribed, small, nonprotein coding RNA. Sequencing selected biological candidate genes within the minimal congenic interval revealed a nonsynonymous variant in SHR transcription factor 4. The minimal congenic interval is syntenic to a region of human chromosome 18 where significant linkage to hypertension was observed in family based linkage studies. These congenic lines provide reagents for identifying causative genes that underlie the chromosome 18 SHR QTLs for hypertension and salt sensitivity. Candidate genes identified in these studies merit further investigation as potentially causative hypertension genes in SHR and human hypertension.
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Affiliation(s)
- Michelle D Johnson
- Institute of Physiology, Czech Academy of Sciences, Vídenská 1083, 142 20 Prague 4, Czech Republic
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202
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de Pontual L, Mathieu Y, Golzio C, Rio M, Malan V, Boddaert N, Soufflet C, Picard C, Durandy A, Dobbie A, Heron D, Isidor B, Motte J, Newburry-Ecob R, Pasquier L, Tardieu M, Viot G, Jaubert F, Munnich A, Colleaux L, Vekemans M, Etchevers H, Lyonnet S, Amiel J. Mutational, functional, and expression studies of the TCF4 gene in Pitt-Hopkins syndrome. Hum Mutat 2009; 30:669-76. [PMID: 19235238 DOI: 10.1002/humu.20935] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pitt-Hopkins syndrome is a severe congenital encephalopathy recently ascribed to de novo heterozygous TCF4 gene mutations. We report a series of 13 novel PHS cases with a TCF4 mutation and show that EEG, brain magnetic resonance imagain (MRI), and immunological investigations provide valuable additional clues to the diagnosis. We confirm a mutational hot spot in the basic domain of the E-protein. Functional studies illustrate that heterodimerisation of mutant TCF4 proteins with a tissue-specific transcription factor is less effective than that homodimerisation in a luciferase reporter assay. We also show that the TCF4 expression pattern in human embryonic development is widespread but not ubiquitous. In summary, we further delineate an underdiagnosed mental retardation syndrome, highlighting TCF4 function during development and facilitating diagnosis within the first year of life.
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Affiliation(s)
- Loïc de Pontual
- Unité INSERM U-781, Université Paris Descartes, Faculté de Médecine, INSERM
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203
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A novel microdeletion syndrome involving 5q14.3-q15: clinical and molecular cytogenetic characterization of three patients. Eur J Hum Genet 2009; 17:1592-9. [PMID: 19471318 DOI: 10.1038/ejhg.2009.90] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Molecular karyotyping is being increasingly applied to delineate novel disease causing microaberrations and related syndromes in patients with mental retardation of unknown aetiology. We report on three unrelated patients with overlapping de novo interstitial microdeletions involving 5q14.3-q15. All three patients presented with severe psychomotor retardation, epilepsy or febrile seizures, muscular hypotonia and variable brain and minor anomalies. Molecular karyotyping revealed three overlapping microdeletions measuring 5.7, 3.9 and 3.6 Mb, respectively. The microdeletions were identified using single nucleotide polymorphism (SNP) arrays (Affymetrix 100K and Illumina 550K) and array comparative genomic hybridization (1 Mb Sanger array-CGH). Confirmation and segregation studies were performed using fluorescence in situ hybridization (FISH) and quantitative PCR. All three aberrations were confirmed and proven to have occurred de novo. The boundaries and sizes of the deletions in the three patients were different, but an overlapping region of around 1.6 Mb in 5q14.3 was defined. It included five genes: CETN3, AC093510.2, POLR3G, LYSMD3 and the proximal part of GPR98/MASS1, a known epilepsy gene. Haploinsufficiency of GPR98/MASS1 is probably responsible for the seizure phenotype in our patients. At least one other gene contained in the commonly deleted region, LYSMD3, shows a high level of central nervous expression during embryogenesis and is also, therefore, a good candidate gene for other central nervous system (CNS) symptoms, such as psychomotor retardation, brain anomalies and muscular hypotonia of the 5q14.3 microdeletion syndrome.
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204
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Dendritic cells: transcriptional control of plasmacytoid dendritic cell development by E2-2. Immunol Cell Biol 2008; 87:1-2. [PMID: 19048021 DOI: 10.1038/icb.2008.93] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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205
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Cisse B, Caton ML, Lehner M, Maeda T, Scheu S, Locksley R, Holmberg D, Zweier C, den Hollander NS, Kant SG, Holter W, Rauch A, Zhuang Y, Reizis B. Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development. Cell 2008; 135:37-48. [PMID: 18854153 DOI: 10.1016/j.cell.2008.09.016] [Citation(s) in RCA: 484] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 07/30/2008] [Accepted: 09/05/2008] [Indexed: 12/22/2022]
Abstract
Plasmacytoid dendritic cells (PDCs) represent a unique immune cell type specialized in type I interferon (IFN) secretion in response to viral nucleic acids. The molecular control of PDC lineage specification has been poorly understood. We report that basic helix-loop-helix transcription factor (E protein) E2-2/Tcf4 is preferentially expressed in murine and human PDCs. Constitutive or inducible deletion of murine E2-2 blocked the development of PDCs but not of other lineages and abolished IFN response to unmethylated DNA. Moreover, E2-2 haploinsufficiency in mice and in human Pitt-Hopkins syndrome patients was associated with aberrant expression profile and impaired IFN response of the PDC. E2-2 directly activated multiple PDC-enriched genes, including transcription factors involved in PDC development (SpiB, Irf8) and function (Irf7). These results identify E2-2 as a specific transcriptional regulator of the PDC lineage in mice and humans and reveal a key function of E proteins in the innate immune system.
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Affiliation(s)
- Babacar Cisse
- Department of Microbiology, Columbia University Medical Center, New York, NY 10032, USA
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206
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Kalscheuer VM, Feenstra I, Van Ravenswaaij-Arts CMA, Smeets DFCM, Menzel C, Ullmann R, Musante L, Ropers HH. Disruption of the TCF4 gene in a girl with mental retardation but without the classical Pitt-Hopkins syndrome. Am J Med Genet A 2008; 146A:2053-9. [PMID: 18627065 DOI: 10.1002/ajmg.a.32419] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have characterized a de novo balanced translocation t(18;20)(q21.1;q11.2) in a female patient with mild to moderate mental retardation (MR) and minor facial anomalies. Breakpoint-mapping by fluorescence in situ hybridization indicated that on chromosome 18, the basic helix-loop-helix transcription factor TCF4 gene is disrupted by the breakpoint. TCF4 plays a role in cell fate determination and differentiation. Only recently, mutations in this gene have been shown to result in Pitt-Hopkins syndrome (PHS), defined by severe MR, epilepsy, mild growth retardation, microcephaly, daily bouts of hyperventilation starting in infancy, and distinctive facial features with deep-set eyes, broad nasal bridge, and wide mouth with widely spaced teeth. Breakpoint mapping on the derivative chromosome 20 indicated that here the rearrangement disrupted the chromodomain helicase DNA binding protein 6 (CHD6) gene. To date, there is no indication that CHD6 is involved in disease. Our study indicates that TCF4 gene mutations are not always associated with classical PHS but can give rise to a much milder clinical phenotype. Thus, the possibility exists that more patients with a less severe encephalopathy carry a mutation in this gene.
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207
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Philippe A, Boddaert N, Vaivre-Douret L, Robel L, Danon-Boileau L, Malan V, de Blois MC, Heron D, Colleaux L, Golse B, Zilbovicius M, Munnich A. Neurobehavioral profile and brain imaging study of the 22q13.3 deletion syndrome in childhood. Pediatrics 2008; 122:e376-82. [PMID: 18625665 DOI: 10.1542/peds.2007-2584] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The 22q13.3 deletion syndrome (Online Mendelian Inheritance in Man No. 606232) is a neurodevelopmental disorder that includes hypotonia, severely impaired development of speech and language, autistic-like behavior, and minor dysmorphic features. Although the number of reported cases is increasing, the 22q13.3 deletion remains underdiagnosed because of failure in recognizing the clinical phenotype and detecting the 22qter deletion by routine chromosome analyses. Our goal is to contribute to the description of the neurobehavioral phenotype and brain abnormalities of this microdeletional syndrome. METHODS We assessed neuromotor, sensory, language, communication, and social development and performed cerebral MRI and study of regional cerebral blood flow measured by positron emission tomography in 8 children carrying the 22q13.3 deletion. RESULTS Despite variability in expression and severity, the children shared a common developmental profile characterized by hypotonia, sleep disorders, and poor response to their environment in early infancy; expressive language deficit contrasting with emergence of social reciprocity from ages approximately 3 to 5 years; sensory processing dysfunction; and neuromotor disorders. Brain MRI findings were normal or showed a thin or morphologically atypical corpus callosum. Positron emission tomography study detected a localized dysfunction of the left temporal polar lobe and amygdala hypoperfusion. CONCLUSIONS The developmental course of the 22q13.3 deletion syndrome belongs to pervasive developmental disorders but is distinct from autism. An improved description of the natural history of this syndrome should help in recognizing this largely underdiagnosed condition.
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Affiliation(s)
- Anne Philippe
- National Institute of Health and Medical Research and Department of Genetics, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
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208
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Kim SK, Jang HR, Kim JH, Kim M, Noh SM, Song KS, Kang GH, Kim HJ, Kim SY, Yoo HS, Kim YS. CpG methylation in exon 1 of transcription factor 4 increases with age in normal gastric mucosa and is associated with gene silencing in intestinal-type gastric cancers. Carcinogenesis 2008; 29:1623-31. [PMID: 18635522 PMCID: PMC2516490 DOI: 10.1093/carcin/bgn110] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transcriptional factor 4 (TCF4), encoding a basic helix-loop-helix transcriptional factor, has recently been demonstrated as a causative gene for Pitt-Hopkins syndrome, a neurodevelopmental disease. Examination of gastric cancers using the restriction landmark genomic scanning technique revealed methylation at a NotI enzyme site in TCF4 intron 8 and further identified CpG dinucleotide hypermethylation in TCF4 exon 1, strongly associated with gene silencing in gastric cancer cell lines. Treatment with 5-aza-2′-deoxycytidine and/or trichostatin A restored TCF4 expression in TCF4-silenced gastric cancer cell lines. Real-time reverse transcription–polymerase chain reaction analysis of 77 paired primary gastric tumor samples revealed that 38% of analyzed tumors had a >2-fold decrease in TCF4 expression compared with adjacent normal-appearing tissue, and the decrease significantly correlated with increased CpG methylation in TCF4 exon 1. Clinicopathologic data showed that decreased TCF4 expression occurred significantly more frequently in intestinal-type (22/37, 59%) than in diffuse-type (7/37, 19%) gastric cancers (P = 0.0004) and likewise more frequently in early (12/18, 67%) than in advanced (17/59, 29%) gastric cancers (P = 0.004). CpG methylation markedly increased with patient age among normal-appearing tissues, suggesting that CpG methylation in gastric mucosa may be one of the earliest events in carcinogenesis of intestinal-type gastric cancers. Furthermore, ectopic expression of TCF4 decreased cell growth in a gastric cancer cell line, and the knock down of TCF4 using small interfering RNA increased cell migration. Based on these results, we propose that the observed frequent epigenetic-mediated TCF4 silencing plays a role in tumor formation and progression.
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Affiliation(s)
- Seung-Kyoon Kim
- Medical Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Department of Functional Genomics, University of Science and Technology, 52 Eoeun-dong, Yuseong-gu, Daejeon 305-806, Republic of Korea
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209
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210
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Deletion 18q21.2q21.32 involving TCF4 in a boy diagnosed by CGH-array. Eur J Med Genet 2008; 51:172-7. [DOI: 10.1016/j.ejmg.2007.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 12/09/2007] [Indexed: 11/23/2022]
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211
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Malan V, Lapierre JM, Vekemans M, Romana S. La CGH array : un bouleversement de la pratique hospitalière en cytogénétique. Ing Rech Biomed 2007. [DOI: 10.1016/j.rbmret.2007.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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212
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Uhrig S, Schlembach D, Waldispuehl-Geigl J, Schaffer W, Geigl J, Klopocki E, Mundlos S, Speicher MR. Impact of array comparative genomic hybridization-derived information on genetic counseling demonstrated by prenatal diagnosis of the TAR (thrombocytopenia-absent-radius) syndrome-associated microdeletion 1q21.1. Am J Hum Genet 2007; 81:866-8. [PMID: 17847015 PMCID: PMC2227939 DOI: 10.1086/521338] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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213
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Flora A, Garcia JJ, Thaller C, Zoghbi HY. The E-protein Tcf4 interacts with Math1 to regulate differentiation of a specific subset of neuronal progenitors. Proc Natl Acad Sci U S A 2007; 104:15382-7. [PMID: 17878293 PMCID: PMC1978485 DOI: 10.1073/pnas.0707456104] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Proneural factors represent <10 transcriptional regulators required for specifying all of the different neurons of the mammalian nervous system. The mechanisms by which such a small number of factors creates this diversity are still unknown. We propose that proteins interacting with proneural factors confer such specificity. To test this hypothesis we isolated proteins that interact with Math1, a proneural transcription factor essential for the establishment of a neural progenitor population (rhombic lip) that gives rise to multiple hindbrain structures and identified the E-protein Tcf4. Interestingly, haploinsufficiency of TCF4 causes the Pitt-Hopkins mental retardation syndrome, underscoring the important role for this protein in neural development. To investigate the functional relevance of the Math1/Tcf4 interaction in vivo, we studied Tcf4(-/-) mice and found that they have disrupted pontine nucleus development. Surprisingly, this selective deficit occurs without affecting other rhombic lip-derived nuclei, despite expression of Math1 and Tcf4 throughout the rhombic lip. Importantly, deletion of any of the other E-protein-encoding genes does not have detectable effects on Math1-dependent neurons, suggesting a specialized role for Tcf4 in distinct neural progenitors. Our findings provide the first in vivo evidence for an exclusive function of dimers formed between a proneural basic helix-loop-helix factor and a specific E-protein, offering insight about the mechanisms underlying transcriptional programs that regulate development of the mammalian nervous system.
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Affiliation(s)
- Adriano Flora
- *Howard Hughes Medical Institute
- Departments of Molecular and Human Genetics
- To whom correspondence may be addressed. E-mail: or
| | - Jesus J. Garcia
- *Howard Hughes Medical Institute
- Departments of Molecular and Human Genetics
| | | | - Huda Y. Zoghbi
- *Howard Hughes Medical Institute
- Departments of Molecular and Human Genetics
- Neuroscience, and
- Pediatrics, and
- **Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030
- To whom correspondence may be addressed. E-mail: or
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214
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Ropers HH. New perspectives for the elucidation of genetic disorders. Am J Hum Genet 2007; 81:199-207. [PMID: 17668371 PMCID: PMC1950818 DOI: 10.1086/520679] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Accepted: 06/06/2007] [Indexed: 12/29/2022] Open
Abstract
For almost 15 years, genome research has focused on the search for major risk factors in common diseases, with disappointing results. Only recently, whole-genome association studies have begun to deliver because of the introduction of high-density single-nucleotide-polymorphism arrays and massive enlargement of cohort sizes, but most of the risk factors detected account for only a small proportion of the total genetic risk, and their diagnostic value is negligible. There is reason to believe that the complexity of many "multifactorial" disorders is primarily due to genetic heterogeneity, with defects of different genes causing the same disease. Moreover, de novo copy-number variation has been identified as a major cause of mental retardation and other complex disorders, suggesting that new mutations are an important, previously overlooked factor in the etiology of complex diseases. These observations support the notion that research into the previously neglected monogenic disorders should become a priority of genome research. Because of the introduction of novel high-throughput, low-cost sequencing methods, sequencing and genotyping will soon converge, with far-reaching implications for the elucidation of genetic disease and health care.
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215
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Brockschmidt A, Todt U, Ryu S, Hoischen A, Landwehr C, Birnbaum S, Frenck W, Radlwimmer B, Lichter P, Engels H, Driever W, Kubisch C, Weber RG. Severe mental retardation with breathing abnormalities (Pitt-Hopkins syndrome) is caused by haploinsufficiency of the neuronal bHLH transcription factor TCF4. Hum Mol Genet 2007; 16:1488-94. [PMID: 17478476 DOI: 10.1093/hmg/ddm099] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pitt-Hopkins syndrome (PHS) is a rare syndromic mental disorder, which is mainly characterized by severe motor and mental retardation including absent language development, a characteristic facial gestalt and episodes of hyperventilation. We report on a female patient with PHS showing severe mental retardation with absent speech, pronounced muscular hypotonia, ataxia, distinctive facial features, such as a coarse face, a broad nasal bridge and a wide mouth, and hyperventilation attacks. In this patient, genomic profiling by array-based comparative genomic hybridization and fluorescence in situ hybridization studies detected and confirmed a de novo 0.5 Mb deletion in 18q21.2 containing a single gene, the basic helix-loop-helix transcription factor TCF4. cDNA and genomic analyses in the patient and her parents demonstrated TCF4 haploinsufficiency as the underlying cause of the disease. Analysis of the embryonal expression pattern of the Danio rerio ortholog, tcf4, by whole-mount in situ hybridization showed a highly specific expression domain in the pallium of the telencephalon during late somitogenesis, when the patterning of the zebrafish brain is advanced and neural differentiation commences. Later expression domains were restricted to several regions in the central nervous system, including continued expression in the pallium of the telencephalon, and starting expression in the diencephalon (thalamus, ventral thalamus and posterior tuberculum), the midbrain tegmentum, the hindbrain and the branchial arches. This expression pattern correlates with the clinical phenotype. Our results show that haploinsufficiency of TCF4 causes PHS and suggest that D. rerio is a valuable model to study the molecular pathogenesis of PHS and the role of TCF4 in brain development.
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Affiliation(s)
- Antje Brockschmidt
- 1Institute of Human Genetics, Rheinische Friedrich-Wilhelms-University, 53111 Bonn, Germany
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