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Arts H, Schmidts M, Bongers EMHF, Oud MM, Duijkers LEM, Yap Z, Stalker J, Yntema JL, Hoischen A, Gilissen C, Veltman JA, Kutkowska-Kaźmierczak A, Kamsteeg EJ, Scambler PJ, Beales PL, Knoers NVAM, Roepman R, Mitchison HM. Pitfalls of whole exome-sequencing: hidden DYNC2H1 mutations in patients with Jeune asphyxiating thoracic dystrophy. Cilia 2012. [PMCID: PMC3555943 DOI: 10.1186/2046-2530-1-s1-p80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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2
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Abstract
BACKGROUND Tbx1 is a member of the Tbox family of binding domain transcription factors. TBX1 maps within the region of chromosome 22q11 deleted in humans with DiGeorge syndrome (DGS), a common genetic disorder characterized by numerous physical manifestations including craniofacial and cardiac anomalies. Mice with homozygous null mutations in Tbx1 phenocopy this disorder and have defects including abnormal cranial ganglia formation and cardiac neural crest cell migration. These defects prompted us to investigate whether extrinsic vagus nerve or intrinsic enteric nervous system abnormalities are prevalent in the gastrointestinal tract of Tbx1 mutant mice. METHODS We used in situ hybridization for Ret, and immunohistochemical staining for neurofilament, HuC/D and βIII-tubulin to study cranial ganglia, vagus nerve, and enteric nervous system development in Tbx1 mutant and control mice. KEY RESULTS In Tbx1(-/-) embryos, cranial ganglia of the glossopharyngeal (IXth) and vagus (Xth) nerves were malformed and abnormally fused. In the gastrointestinal tract, the vagus nerves adjacent to the esophagus were severely hypoplastic and they did not extend beyond the gastro-esophageal junction nor project branches within the stomach wall, as was observed in Tbx1(+/+) mice. CONCLUSIONS & INFERENCES Although cranial ganglia morphology appeared normal in Tbx1(+/-) mice, these animals had a spectrum of stomach vagus innervation defects ranging from mild to severe. In all Tbx1 genotypes, the intrinsic enteric nervous system developed normally. The deficit in vagal innervation of the stomach in mice mutant for a gene implicated in DGS raises the possibility that similar defects may underlie a number of as yet unidentified/unreported congenital disorders affecting gastrointestinal function.
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Affiliation(s)
- A Calmont
- Molecular Medicine Unit, UCL Institute of Child Health, London, UK
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3
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Aza-Carmona M, Shears DJ, Yuste-Checa P, Barca-Tierno V, Hisado-Oliva A, Belinchon A, Benito-Sanz S, Rodriguez JI, Argente J, Campos-Barros A, Scambler PJ, Heath KE. SHOX interacts with the chondrogenic transcription factors SOX5 and SOX6 to activate the aggrecan enhancer. Hum Mol Genet 2011; 20:1547-59. [DOI: 10.1093/hmg/ddr032] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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4
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Chu CS, Rabinowitz YS, Scambler PJ, Graham JM. 479 GENOTYPE-PHENOTYPE CORRELATION OF MUTATIONS IN FRAS1 WITH FRASER SYNDROME PATIENTS. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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5
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Lemonde HA, Custard EJ, Bouquet J, Duran M, Overmars H, Scambler PJ, Clayton PT. Mutations in SRD5B1 (AKR1D1), the gene encoding delta(4)-3-oxosteroid 5beta-reductase, in hepatitis and liver failure in infancy. Gut 2003; 52:1494-9. [PMID: 12970144 PMCID: PMC1773813 DOI: 10.1136/gut.52.10.1494] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND A substantial group of patients with cholestatic liver disease in infancy excrete, as the major urinary bile acids, the glycine and taurine conjugates of 7alpha-hydroxy-3-oxo-4-cholenoic acid and 7alpha,12alpha-dihydroxy-3-oxo-4-cholenoic acid. It has been proposed that some (but not all) of these have mutations in the gene encoding delta(4)-3-oxosteroid 5beta-reductase (SRD5B1; AKR1D1, OMIM 604741). AIMS Our aim was to identify mutations in the SRD5B1 gene in patients in whom chenodeoxycholic acid and cholic acid were absent or present at low concentrations in plasma and urine, as these seemed strong candidates for genetic 5beta-reductase deficiency. PATIENTS AND SUBJECTS We studied three patients with neonatal onset cholestatic liver disease and normal gamma-glutamyl transpeptidase in whom 3-oxo-delta(4) bile acids were the major bile acids in urine and plasma and saturated bile acids were at low concentration or undetectable. Any base changes detected in SRD5B1 were sought in the parents and siblings and in 50 ethnically matched control subjects. METHODS DNA was extracted from blood and the nine exons of SRD5B1 were amplified and sequenced. Restriction enzymes were used to screen the DNA of parents, siblings, and controls. RESULTS Mutations in the SRD5B1 gene were identified in all three children. Patient MS was homozygous for a missense mutation (662 C>T) causing a Pro198Leu amino acid substitution; patient BH was homozygous for a single base deletion (511 delT) causing a frame shift and a premature stop codon in exon 5; and patient RM was homozygous for a missense mutation (385 C>T) causing a Leu106Phe amino acid substitution. All had liver biopsies showing a giant cell hepatitis; in two, prominent extramedullary haemopoiesis was noted. MS was cured by treatment with chenodeoxycholic acid and cholic acid; BH showed initial improvement but then deteriorated and required liver transplantation; RM had advanced liver disease when treatment was started and also progressed to liver failure. CONCLUSIONS Analysis of blood samples for SRD5B1 mutations can be used to diagnose genetic 5beta-reductase deficiency and distinguish these patients from those who have another cause of 3-oxo-delta(4) bile aciduria, for example, severe liver damage. Patients with genetic 5beta-reductase deficiency may respond well to treatment with chenodeoxycholic acid and cholic acid if liver disease is not too advanced.
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Affiliation(s)
- H A Lemonde
- Biochemistry, Endocrinology, and Metabolism Unit, Institute of Child Health, University College London with Great Ormond Street Hospital for Children NHS Trust, London, UK
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6
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Morgan NV, Bacchelli C, Gissen P, Morton J, Ferrero GB, Silengo M, Labrune P, Casteels I, Hall C, Cox P, Kelly DA, Trembath RC, Scambler PJ, Maher ER, Goodman FR, Johnson CA. A locus for asphyxiating thoracic dystrophy, ATD, maps to chromosome 15q13. J Med Genet 2003; 40:431-5. [PMID: 12807964 PMCID: PMC1735497 DOI: 10.1136/jmg.40.6.431] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Asphyxiating thoracic dystrophy (ATD), or Jeune syndrome, is a multisystem autosomal recessive disorder associated with a characteristic skeletal dysplasia and variable renal, hepatic, pancreatic, and retinal abnormalities. We have performed a genome wide linkage search using autozygosity mapping in a cohort of four consanguineous families with ATD, three of which originate from Pakistan, and one from southern Italy. In these families, as well as in a fifth consanguineous family from France, we localised a novel ATD locus (ATD) to chromosome 15q13, with a maximum cumulative two point lod score at D15S1031 (Zmax=3.77 at theta=0.00). Five consanguineous families shared a 1.2 cM region of homozygosity between D15S165 and D15S1010. Investigation of a further four European kindreds, with no known parental consanguinity, showed evidence of marker homozygosity across a similar interval. Families with both mild and severe forms of ATD mapped to 15q13, but mutation analysis of two candidate genes, GREMLIN and FORMIN, did not show pathogenic mutations.
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Affiliation(s)
- N V Morgan
- Section of Medical and Molecular Genetics, Department of Paediatrics and Child Health, University of Birmingham Medical School, Birmingham B15 2TT, UK
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7
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Debeer P, Bacchelli C, Scambler PJ, De Smet L, Fryns JP, Goodman FR. Severe digital abnormalities in a patient heterozygous for both a novel missense mutation in HOXD13 and a polyalanine tract expansion in HOXA13. J Med Genet 2002; 39:852-6. [PMID: 12414828 PMCID: PMC1735011 DOI: 10.1136/jmg.39.11.852] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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8
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Lichtner P, Attié-Bitach T, Schuffenhauer S, Henwood J, Bouvagnet P, Scambler PJ, Meitinger T, Vekemans M. Expression and mutation analysis of BRUNOL3, a candidate gene for heart and thymus developmental defects associated with partial monosomy 10p. J Mol Med (Berl) 2002; 80:431-42. [PMID: 12110949 DOI: 10.1007/s00109-002-0331-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2001] [Accepted: 01/11/2002] [Indexed: 11/30/2022]
Abstract
Partial monosomy 10p is a rare chromosomal aberration. Patients often show symptoms of the DiGeorge/velocardiofacial syndrome spectrum. The phenotype is the result of haploinsufficiency of at least two regions on 10p, the HDR1 region associated with hypoparathyroidism, sensorineural deafness, and renal defects (HDR syndrome) and the more proximal region DGCR2 responsible for heart defects and thymus hypoplasia/aplasia. While GATA3 was identified as the disease causing gene for HDR syndrome, no genes have been identified thus far for the symptoms associated with DGCR2 haploinsufficiency. We constructed a deletion map of partial monosomy 10p patients and narrowed the critical region DGCR2 to about 300 kb. The genomic draft sequence of this region contains only one known gene, BRUNOL3 ( NAPOR, CUGBP2, ETR3). In situ hybridization of human embryos and fetuses revealed as well as in other tissues a strong expression of BRUNOL3 in thymus during different developmental stages. BRUNOL3 appears to be an important factor for thymus development and is therefore a candidate gene for the thymus hypoplasia/aplasia seen in partial monosomy 10p patients. We did not find BRUNOL3 mutations in 92 DiGeorge syndrome-like patients without chromosomal deletions and in 8 parents with congenital heart defect children.
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Affiliation(s)
- P Lichtner
- Institute of Human Genetics, Klinikum Rechts der Isar, Technical University, Munich, Germany.
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9
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Katsanis N, Ansley SJ, Badano JL, Eichers ER, Lewis RA, Hoskins BE, Scambler PJ, Davidson WS, Beales PL, Lupski JR. Triallelic inheritance in Bardet-Biedl syndrome, a Mendelian recessive disorder. Science 2001; 293:2256-9. [PMID: 11567139 DOI: 10.1126/science.1063525] [Citation(s) in RCA: 405] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a genetically heterogeneous disorder characterized by multiple clinical features that include pigmentary retinal dystrophy, polydactyly, obesity, developmental delay, and renal defects. BBS is considered an autosomal recessive disorder, and recent positional cloning efforts have identified two BBS genes (BBS2 and BBS6). We screened our cohort of 163 BBS families for mutations in both BBS2 and BBS6 and report the presence of three mutant alleles in affected individuals in four pedigrees. In addition, we detected unaffected individuals in two pedigrees who carry two BBS2 mutations but not a BBS6 mutation. We therefore propose that BBS may not be a single-gene recessive disease but a complex trait requiring three mutant alleles to manifest the phenotype. This triallelic model of disease transmission may be important in the study of both Mendelian and multifactorial disorders.
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Affiliation(s)
- N Katsanis
- Department of Molecular and Human Genetics, The Texas Children's Hospital, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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11
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Lindsay EA, Vitelli F, Su H, Morishima M, Huynh T, Pramparo T, Jurecic V, Ogunrinu G, Sutherland HF, Scambler PJ, Bradley A, Baldini A. Tbx1 haploinsufficieny in the DiGeorge syndrome region causes aortic arch defects in mice. Nature 2001; 410:97-101. [PMID: 11242049 DOI: 10.1038/35065105] [Citation(s) in RCA: 684] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DiGeorge syndrome is characterized by cardiovascular, thymus and parathyroid defects and craniofacial anomalies, and is usually caused by a heterozygous deletion of chromosomal region 22q11.2 (del22q11) (ref. 1). A targeted, heterozygous deletion, named Df(16)1, encompassing around 1 megabase of the homologous region in mouse causes cardiovascular abnormalities characteristic of the human disease. Here we have used a combination of chromosome engineering and P1 artificial chromosome transgenesis to localize the haploinsufficient gene in the region, Tbx1. We show that Tbx1, a member of the T-box transcription factor family, is required for normal development of the pharyngeal arch arteries in a gene dosage-dependent manner. Deletion of one copy of Tbx1 affects the development of the fourth pharyngeal arch arteries, whereas homozygous mutation severely disrupts the pharyngeal arch artery system. Our data show that haploinsufficiency of Tbx1 is sufficient to generate at least one important component of the DiGeorge syndrome phenotype in mice, and demonstrate the suitability of the mouse for the genetic dissection of microdeletion syndromes.
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Affiliation(s)
- E A Lindsay
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
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12
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Abstract
HOX genes play a fundamental role in the development of the vertebrate central nervous system, axial skeleton, limbs, gut, urogenital tract and external genitalia, but it is only in the last 4 years that mutations in two of the 39 human HOX genes have been shown to cause congenital malformations; HOXD13, which is mutated in synpolydactyly, and HOXA13, which is mutated in Hand-Foot-Genital syndrome. Here we review the mutations already identified in these two genes, consider how these mutations may act, and discuss the possibility that further mutations remain to be discovered both in developmental disorders and in cancer.
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Affiliation(s)
- F R Goodman
- Molecular Medicine Unit, Institute of Child Health, London, UK.
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13
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Robertson SP, Shears DJ, Oei P, Winter RM, Scambler PJ, Aftimos S, Savarirayan R. Homozygous deletion of SHOX in a mentally retarded male with Langer mesomelic dysplasia. J Med Genet 2000; 37:959-64. [PMID: 11186941 PMCID: PMC1734489 DOI: 10.1136/jmg.37.12.959] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
DiGeorge syndrome, velocardiofacial syndrome and various other malformations have been described in association with deletions and translocations involving human chromosome 22q11. Many of the structural malformations observed are also seen in animal models of neural crest disruption suggesting that the haplo-insufficiency resulting from the deletion somehow affects this group of cells or their interactions. Over the past few years it has been shown that the deletion predisposes to a range of psychotic conditions prompting the hypothesis that the deleted region may contain a predisposition locus for psychotic illness. The DiGeorge chromosomal region has been entirely sequenced and many of the genes mapping to the deletion interval have been studied in some detail. Despite these efforts, no gene has yet been proved to play a defined role in the pathogenesis of the syndrome. Current efforts are directed at the study of engineered chromosome mouse models which offer the potential to dissect at least some of the developmental pathways disrupted in this intriguing group of malformation syndromes.
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Affiliation(s)
- P J Scambler
- Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, Room 211, London WC1N 1EH, UK.
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15
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Goodman FR, Bacchelli C, Brady AF, Brueton LA, Fryns JP, Mortlock DP, Innis JW, Holmes LB, Donnenfeld AE, Feingold M, Beemer FA, Hennekam RC, Scambler PJ. Novel HOXA13 mutations and the phenotypic spectrum of hand-foot-genital syndrome. Am J Hum Genet 2000; 67:197-202. [PMID: 10839976 PMCID: PMC1287077 DOI: 10.1086/302961] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2000] [Accepted: 05/17/2000] [Indexed: 11/03/2022] Open
Abstract
Hand-foot-genital syndrome (HFGS) is a rare, dominantly inherited condition affecting the distal limbs and genitourinary tract. A nonsense mutation in the homeobox of HOXA13 has been identified in one affected family, making HFGS the second human syndrome shown to be caused by a HOX gene mutation. We have therefore examined HOXA13 in two new and four previously reported families with features of HFGS. In families 1, 2, and 3, nonsense mutations truncating the encoded protein N-terminal to or within the homeodomain produce typical limb and genitourinary abnormalities; in family 4, an expansion of an N-terminal polyalanine tract produces a similar phenotype; in family 5, a missense mutation, which alters an invariant domain, produces an exceptionally severe limb phenotype; and in family 6, in which limb abnormalities were atypical, no HOXA13 mutation could be detected. Mutations in HOXA13 can therefore cause more-severe limb abnormalities than previously suspected and may act by more than one mechanism.
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Affiliation(s)
- F R Goodman
- Molecular Medicine Unit, Institute of Child Health, London, United Kingdom.
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16
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Berend SA, Spikes AS, Kashork CD, Wu JM, Daw SC, Scambler PJ, Shaffer LG. Dual-probe fluorescence in situ hybridization assay for detecting deletions associated with VCFS/DiGeorge syndrome I and DiGeorge syndrome II loci. Am J Med Genet 2000; 91:313-7. [PMID: 10766989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Over 90% of patients with DiGeorge syndrome (DGS) or velocardiofacial syndrome (VCFS) have a microdeletion at 22q11.2. Given that these deletions are difficult to visualize at the light microscopic level, fluorescence in situ hybridization (FISH) has been instrumental in the diagnosis of this disorder. Deletions on the short arm of chromosome 10 are also associated with a DGS-like phenotype. Since deletions at 22q11.2 and at 10p13p14 result in similar findings, we have developed a dual-probe FISH assay for screening samples referred for DGS or VCFS in the clinical laboratory. This assay includes two test probes for the loci, DGSI at 22q11.2 and DGSII at 10p13p14, and centromeric probes for chromosomes 10 and 22. Of 412 patients tested, 54 were found to be deleted for the DGSI locus on chromosome 22 (13%), and a single patient was found deleted for the DGSII locus on chromosome 10 (0. 24%). The patient with the 10p deletion had facial features consistent with VCFS, plus sensorineural hearing loss, and renal anomalies. Cytogenetic analysis showed a large deletion of 10p [46, XX,del(10)(p12.2p14)] and FISH using a 10p telomere region-specific probe confirmed the interstitial nature of the deletion. Analysis for the DGSI and the DGSII loci suggests that the deletion of the DGSII locus on chromosome 10 may be 50 times less frequent than the deletion of DGSI on chromosome 22. The incidence of deletions at 22q11.2 has been estimated to be 1 in 4000 newborns; therefore, the deletion at 10p13p14 may be estimated to occur in 1 in 200,000 live births.
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Affiliation(s)
- S A Berend
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.
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17
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Wang J, Spitz L, Hayward R, Kiely E, Hall CM, O'Donoghue DP, Palmer R, Goodman FR, Scambler PJ, Winter RM, Reardon W. Sacral dysgenesis associated with terminal deletion of chromosome 7q: a report of two families. Eur J Pediatr 1999; 158:902-5. [PMID: 10541945 DOI: 10.1007/s004310051238] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Most cases of sacral dysgenesis are considered to be sporadic events. We present two families in whom the presence of associated clinical features prompted specific investigation of chromosome 7, leading to the identification of an underlying chromosome 7q deletion causing sacral dysgenesis. All affected individuals had microcephaly and developmental delay. Detailed cytogenetic studies confirmed that all three affected individuals had a deletion of chromosome 7q associated with their sacral dysgenesis, developmental delay and related problems. The three affected patients were studied clinically, radiologically and cytogenetically. Eleven unaffected individuals from the two families were also investigated by genetic studies, specifically evaluating chromosome 7. CONCLUSION It is important that detailed family history, evaluation of associated malformations and the overall clinical picture be considered in identifying the underlying diagnosis in cases of anal stenosis/sacral agenesis. The cases we present demonstrate the value of detailed chromosome studies in such situations.
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Affiliation(s)
- J Wang
- Great Ormond Street Hospital for Children, London, UK
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18
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Kimber WL, Hsieh P, Hirotsune S, Yuva-Paylor L, Sutherland HF, Chen A, Ruiz-Lozano P, Hoogstraten-Miller SL, Chien KR, Paylor R, Scambler PJ, Wynshaw-Boris A. Deletion of 150 kb in the minimal DiGeorge/velocardiofacial syndrome critical region in mouse. Hum Mol Genet 1999; 8:2229-37. [PMID: 10545603 DOI: 10.1093/hmg/8.12.2229] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Deletions or rearrangements of human chromosome 22q11 lead to a variety of related clinical syndromes such as DiGeorge syndrome (DGS) and velo--cardiofacial syndrome (VCFS). In addition, patients with 22q11 deletions have an increased incidence of schizophrenia and several studies have mapped susceptibility loci for schizophrenia to this region. Human molecular genetic studies have so far failed to identify the crucial genes or disruption mechanisms that result in these disorders. We have used gene targeting in the mouse to delete a defined region within the conserved DGS critical region (DGCR) on mouse chromosome 16 to prospectively investigate the role of the mouse DGCR in 22q11 syndromes. The deletion spans a conserved portion ( approximately 150 kb) of the proximal region of the DGCR, containing at least seven genes ( Znf74l, Idd, Tsk1, Tsk2, Es2, Gscl and Ctp ). Mice heterozygous for this deletion display no findings of DGS/VCFS in either inbred or mixed backgrounds. However, heterozygous mice display an increase in prepulse inhibition of the startle response, a manifestation of sensorimotor gating that is reduced in humans with schizophrenia. Homozygous deleted mice die soon after implantation, demonstrating that the deleted region contains genes essential for early post-implantation embryonic development. These results suggest that heterozygous deletion of this portion of the DGCR is sufficient for sensorimotor gating abnormalities, but not sufficient to produce the common features of DGS/VCFS in the mouse.
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Affiliation(s)
- W L Kimber
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Magnaghi P, Roberts C, Lorain S, Lipinski M, Scambler PJ. HIRA, a mammalian homologue of Saccharomyces cerevisiae transcriptional co-repressors, interacts with Pax3. Nat Genet 1998; 20:74-7. [PMID: 9731536 DOI: 10.1038/1739] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
HIRA maps to the DiGeorge/velocardiofacial syndrome critical region (DGCR) at 22q11 (refs 1,2) and encodes a WD40 repeat protein similar to yeast Hir1p and Hir2p. These transcriptional co-repressors regulate cell cycle-dependent histone gene transcription, possibly by remodelling local chromatin structure. We report an interaction between HIRA and the transcription factor Pax3. Pax3 haploinsufficiency results in the mouse splotch and human Waardenburg syndrome (WSI and WSIII) phenotypes. Mice homozygous for Pax3 mutations die in utero with a phenocopy of DGS, or neonatally with neural tube defects. HIRA was also found to interact with core histones. Thus, altered stoichiometry of complexes containing HIRA may be important for the development of structures affected in WS and DGS.
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Affiliation(s)
- P Magnaghi
- Molecular Medicine Unit, Institute of Child Health, London, UK
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21
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Abstract
Chromosome deletions leading to the hemizygous loss of groups of contiguous genes are a major cause of human congenital defects. In some syndromes haploinsufficiency of a single gene causes the majority of the syndromal features, whereas other diseases are thought to be the consequences of a combined haploinsufficiency. In the case of the DiGeorge and velocardiofacial syndromes, caused by deletions within 22q11, the genetic analyses have so far failed to implicate a single gene. By virtue of FISH analysis and the creation of a BAC/P1 genomic clone contig we have mapped 19 murine homologues of genes and nine EST groups from the region deleted in DiGeorge syndrome and found them to be linked on mouse chromosome 16. Rearrangements during the divergence of mouse and human have led to differing gene orders in the two species, with implications for the most appropriate means of mimicking particular human deletions. The map confirms and extends previous analyses and the contig resources toward the generation of targeted deletions in the mouse.
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MESH Headings
- Animals
- Bacteriophage P1/genetics
- Cell Cycle Proteins
- Chromosome Mapping/methods
- Chromosomes, Artificial, Yeast/chemistry
- Chromosomes, Artificial, Yeast/genetics
- Chromosomes, Bacterial/genetics
- Chromosomes, Human, Pair 22/genetics
- Cloning, Molecular
- DiGeorge Syndrome/genetics
- Histone Chaperones
- Humans
- Mice
- Mice, Inbred Strains
- Nuclear Proteins/genetics
- Sequence Analysis, DNA
- Transcription Factors/genetics
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Affiliation(s)
- H F Sutherland
- Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom
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22
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McKie JM, Wadey RB, Sutherland HF, Taylor CL, Scambler PJ. Direct selection of conserved cDNAs from the DiGeorge critical region: isolation of a novel CDC45-like gene. Genome Res 1998; 8:834-41. [PMID: 9724329 PMCID: PMC310757 DOI: 10.1101/gr.8.8.834] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have used a modified direct selection technique to detect transcripts that are both evolutionary conserved and developmentally expressed. The enrichment for homologous mouse cDNAs by use of human genomic DNA as template is shown to be an efficient and rapid approach for generating transcript maps. Deletions of human 22q11 are associated with several clinical syndromes, with overlapping phenotypes, for example, velocardiofacial syndrome (VCFS) and DiGeorge syndrome (DGS). A large number of transcriptional units exist within the defined critical region, many of which have been identified previously by direct selection. However, no single obvious candidate gene for the VCFS/DGS phenotype has yet been found. Our technique has been applied to the DiGeorge critical region and has resulted in the isolation of a novel candidate gene, Cdc45l2, similar to yeast Cdc45p. [The sequence data described in this paper have been submitted to the EMBL data library under accession nos. AJ0223728 and AF0223729.]
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Affiliation(s)
- J M McKie
- Institute of Child Health, University College London Medical School, London WC1N 1EH, UK
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23
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Matsuoka R, Kimura M, Scambler PJ, Morrow BE, Imamura S, Minoshima S, Shimizu N, Yamagishi H, Joh-o K, Watanabe S, Oyama K, Saji T, Ando M, Takao A, Momma K. Molecular and clinical study of 183 patients with conotruncal anomaly face syndrome. Hum Genet 1998; 103:70-80. [PMID: 9737780 DOI: 10.1007/s004390050786] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
To investigate molecular and clinical aspects of conotruncal anomaly face (CAF), we studied the correlation between deletion size and phenotype and the mode of inheritance in 183 conotruncal anomaly face syndrome (CAFS) patients. Hemizygosity for a region of 22ql1.2 was found in 180 (98%) of the patients with CAFS by fluorescence in situ hybridization (FISH) using the N25(D22S75) DiGeorge critical region (DGCR) probe. No hemizygosity was found in three (2%) of the patients with CAFS by FISH using nine DiGeorge critical region probes and a SD1OP1 probe (DGA II locus). None of these three patients had mental retardation and just one had nasal intonation, which was observed in almost all of the 180 CAFS patients who carried deletions (mental retardation, 92%; nasal voice, 88%). Nineteen of 143 families (13%) had familial CAFS and 16 affected parents (84%) were mothers. Although only two of the affected parents had cardiovascular anomalies, the deletion size in the 16 affected parents and their affected family members, who were studied by FISH analysis, was the same. It indicates that extragenic factors may play a role in the genesis of phenotypic variability, especially in patients with cardiovascular anomalies. No familial cases were found among CAFS patients with absent thymus/DiGeorge anomaly (DGA). Also, in all 18 CAFS patients with completely absent thymus/DGA and all 6 CAFS patients with schizophrenia, it was revealed that the deletion was longer distally. A study of the origin of the deletion using microsatellite analyses in 48 de novo patients showed that in 65% of CAFS patients it was maternal, while in 64% of DGA patients it was paternal. The findings of this study indicated that CAF was almost always associated with the deletion of 22ql1.2. As well as the major features of the syndrome, other notable extracardiac anomalies were found to be susceptibility to infection, schizophrenia, atrophy or dysmorphism of the brain, thrombocytopenia, short stature, facial palsy, anal atresia, and mild limb abnormalities.
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Affiliation(s)
- R Matsuoka
- Department of Pediatric Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Japan.
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24
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Shears DJ, Vassal HJ, Goodman FR, Palmer RW, Reardon W, Superti-Furga A, Scambler PJ, Winter RM. Mutation and deletion of the pseudoautosomal gene SHOX cause Leri-Weill dyschondrosteosis. Nat Genet 1998; 19:70-3. [PMID: 9590293 DOI: 10.1038/ng0198-70] [Citation(s) in RCA: 236] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Leri-Weill Dyschondrosteosis (LWD; OMIM 127300) is a dominantly inherited skeletal dysplasia characterized by disproportionate short stature with predominantly mesomelic limb shortening. Expression is variable and consistently more severe in females, who frequently display the Madelung deformity of the forearm (shortening and bowing of the radius with dorsal subluxation of the distal ulna). The rare Langer Mesomelic Dysplasia (LD; OMIM 249700), characterized by severe short stature with hypoplasia/aplasia of the ulna and fibula, has been postulated to be the homozygous form of LWD (refs 4-6). In a six-generation pedigree with LWD, we established linkage to the marker DXYS6814 in the pseudoautosomal region (PAR1) of the X and Y chromosomes (Z max=6.28; theta=0). Linkage analysis of three smaller pedigrees increased the lod score to 8.68 (theta=0). We identified submicroscopic PAR1 deletions encompassing the recently described short stature homeobox-containing gene SHOX (refs 7,8) segregating with the LWD phenotype in 5 families. A point mutation leading to a premature stop in exon 4 of SHOX was identified in one LWD family.
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Affiliation(s)
- D J Shears
- Department of Clinical Genetics, Institute of Child Health, London, UK
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25
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Lindsay EA, Harvey EL, Scambler PJ, Baldini A. ES2, a gene deleted in DiGeorge syndrome, encodes a nuclear protein and is expressed during early mouse development, where it shares an expression domain with a Goosecoid-like gene. Hum Mol Genet 1998; 7:629-35. [PMID: 9499415 DOI: 10.1093/hmg/7.4.629] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
ES2 is a gene deleted in DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS) which has homologs in species as distant as Caenorhabditis elegans and Drosophila . The function of ES2 is unknown, and the predicted protein sequence does not contain motifs which suggest a particular role in the developmental defects present in DGS and VCFS. Here we show that the mouse homolog, Es2 , is transcribed in two forms resulting from the use of alternative polyadenylation signals. Structural analysis programs predict that the Es2 -encoded peptide has a coiled-coil domain, and transfection experiments with an Es2 -green fluorescent protein (GFP) fusion construct show that the peptide is recruited into the nucleus. Es2 is highly expressed during mouse embryogenesis from E7 onwards. In situ hybridization with an RNA probe revealed that the gene is widely expressed; however, relatively higher expression was detected in the nervous system, with a particularly high area of expression in a sub-region of the pons. The Es2 expression domain in the pons is shared with a Goosecoid-like gene ( Gscl) which is located upstream of Es2 , and raises the possibility that the two genes share regulatory elements and/or interact in this region of the developing brain. This finding suggests that different genes in the deleted region may be functionally related and might explain the occurrence of the characteristic phenotype in patients with non-overlapping genetic lesions.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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26
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Yan W, Jacobsen LK, Krasnewich DM, Guan XY, Lenane MC, Paul SP, Dalwadi HN, Zhang H, Long RT, Kumra S, Martin BM, Scambler PJ, Trent JM, Sidransky E, Ginns EI, Rapoport JL. Chromosome 22q11.2 interstitial deletions among childhood-onset schizophrenics and "multidimensionally impaired". Am J Med Genet 1998; 81:41-3. [PMID: 9514586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Since its first description almost a century ago schizophrenia with childhood onset, a rare yet devastating disorder, has been diagnosed in children as young as age 5. Recently, the velocardiofacial syndrome, whose underlying cause is interstitial deletions of 22q11.2, was found in 2 of 100 cases of schizophrenics with adult onset [Karayiorgou et al., Proc Natl Acad Sci USA 92: 7612-7616, 1995]. No study has documented the prevalence of velocardiofacial syndrome and the 22q11.2 deletion in a population of schizophrenics with childhood onset. Here we describe the result of such a study in a sample originally selected for a trial of atypical antipsychotic drugs. A separate group of patients was also included in the study; they can best be accounted for as a variant of childhood-onset schizophrenia (COS) and had been provisionally termed "multidimensionally impaired." Fluorescent in situ hybridization screening of 32 COS and 21 multidimensionally impaired patients revealed 1 COS patient with an interstitial deletion spanning at least 2.5 megabases.
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Affiliation(s)
- W Yan
- Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20892-4405, USA.
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27
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McKie JM, Sutherland HF, Harvey E, Kim UJ, Scambler PJ. A human gene similar to Drosophila melanogaster peanut maps to the DiGeorge syndrome region of 22q11. Hum Genet 1997; 101:6-12. [PMID: 9385360 DOI: 10.1007/s004390050576] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A Drosophila-related expressed sequence tag (DRES) with sequence similarity to the peanut gene has previously been localized to human chromosome 22q11. We have isolated the cDNA corresponding to this DRES and show that it is a novel member of the family of septin genes, which encode proteins with GTPase activity thought to interact during cytokinesis. The predicted protein has P-loop nucleotide binding and GTPase motifs. The gene, which we call PNUTL1, maps to the region of 22q11.2 frequently deleted in DiGeorge and velo-cardio-facial syndromes and is particularly highly expressed in the brain. The mouse homologue, Pnutl1, maps to MMU16 adding to the growing number of genes from the DiGeorge syndrome region that map to this chromosome.
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Affiliation(s)
- J M McKie
- Molecular Medicine Unit, Institute of Child Health, London, UK
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28
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Ryan AK, Goodship JA, Wilson DI, Philip N, Levy A, Seidel H, Schuffenhauer S, Oechsler H, Belohradsky B, Prieur M, Aurias A, Raymond FL, Clayton-Smith J, Hatchwell E, McKeown C, Beemer FA, Dallapiccola B, Novelli G, Hurst JA, Ignatius J, Green AJ, Winter RM, Brueton L, Brøndum-Nielsen K, Scambler PJ. Spectrum of clinical features associated with interstitial chromosome 22q11 deletions: a European collaborative study. J Med Genet 1997; 34:798-804. [PMID: 9350810 PMCID: PMC1051084 DOI: 10.1136/jmg.34.10.798] [Citation(s) in RCA: 899] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We present clinical data on 558 patients with deletions within the DiGeorge syndrome critical region of chromosome 22q11. Twenty-eight percent of the cases where parents had been tested had inherited deletions, with a marked excess of maternally inherited deletions (maternal 61, paternal 18). Eight percent of the patients had died, over half of these within a month of birth and the majority within 6 months. All but one of the deaths were the result of congenital heart disease. Clinically significant immunological problems were very uncommon. Nine percent of patients had cleft palate and 32% had velopharyngeal insufficiency, 60% of patients were hypocalcaemic, 75% of patients had cardiac problems, and 36% of patients who had abdominal ultrasound had a renal abnormality. Sixty-two percent of surviving patients were developmentally normal or had only mild learning problems. The majority of patients were constitutionally small, with 36% of patients below the 3rd centile for either height or weight parameters.
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Affiliation(s)
- A K Ryan
- Department of Human Genetics, University of Newcastle upon Tyne, UK
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29
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Goodman FR, Mundlos S, Muragaki Y, Donnai D, Giovannucci-Uzielli ML, Lapi E, Majewski F, McGaughran J, McKeown C, Reardon W, Upton J, Winter RM, Olsen BR, Scambler PJ. Synpolydactyly phenotypes correlate with size of expansions in HOXD13 polyalanine tract. Proc Natl Acad Sci U S A 1997; 94:7458-63. [PMID: 9207113 PMCID: PMC23843 DOI: 10.1073/pnas.94.14.7458] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/1996] [Accepted: 05/16/1997] [Indexed: 02/04/2023] Open
Abstract
Synpolydactyly (SPD) is a dominantly inherited congenital limb malformation. Typical cases have 3/4 finger and 4/5 toe syndactyly, with a duplicated digit in the syndactylous web, but incomplete penetrance and variable expressivity are common. The condition has recently been shown to be caused by expansions of an imperfect trinucleotide repeat sequence encoding a 15-residue polyalanine tract in HOXD13. We have studied 16 new and 4 previously published SPD families, with between 7 and 14 extra residues in the tract, to analyze the molecular basis for the observed variation in phenotype. Although there is no evidence of change in expansion size within families, even over six generations, there is a highly significant increase in the penetrance and severity of phenotype with increasing expansion size, affecting both hands (P = 0.012) and feet (P < 0. 00005). Affected individuals from a family with a 14-alanine expansion, the largest so far reported, all have a strikingly similar and unusually severe limb phenotype, involving the first digits and distal carpals. Affected males from this family also have hypospadias, not previously described in SPD, but consistent with HOXD13 expression in the developing genital tubercle. The remarkable correlation between phenotype and expansion size suggests that expansion of the tract leads to a specific gain of function in the mutant HOXD13 protein, and has interesting implications for the role of polyalanine tracts in the control of transcription.
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Affiliation(s)
- F R Goodman
- Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, United Kingdom
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30
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Taylor C, Wadey R, O'Donnell H, Roberts C, Mattei MG, Kimber WL, Wynshaw-Boris A, Scambler PJ. Cloning and mapping of murine Dgcr2 and its homology to the Sez-12 seizure-related protein. Mamm Genome 1997; 8:371-5. [PMID: 9107688 DOI: 10.1007/s003359900445] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- C Taylor
- Molecular Medicine Unit, Institute of Child Health, 30, Guilford St., London WC1N 1EH, UK
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31
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Dixon J, Edwards SJ, Anderson I, Brass A, Scambler PJ, Dixon MJ. Identification of the complete coding sequence and genomic organization of the Treacher Collins syndrome gene. Genome Res 1997; 7:223-34. [PMID: 9074926 DOI: 10.1101/gr.7.3.223] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, the features of which include conductive hearing loss and cleft palate. Recently, the demonstration of a series of 10 mutations within a partial-length cDNA clone have indicated that the TCS gene (TCOF1) has been positionally cloned. Although it has been shown that the gene is expressed in a wide variety of fetal and adult tissues, database sequence comparisons have failed to provide significant information on the function of the gene. In the current investigation, a combination of cDNA library screening and rapid amplification of cDNA ends has permitted the isolation of the complete coding sequence of TCOF1, which is encoded by 26 exons and predicts a low complexity, serine/alanine-rich protein of approximately 144 kD. The use of a variety of bioinformatics tools has resulted in the identification of repeated units within the gene, each of which maps onto an individual exon. The predicted protein Treacle contains numerous potential phosphorylaiton sites, a number of which map to similar positions within the repeated units, and shows weak but significant homology to the nucleolar phosphoproteins. Although the precise function of Treacle remains unknown, these observations suggest that phosphorylation may be important for its role in early embryonic development and that it may play a role in nucleolar-cytoplasmic shuttling. The information presented in this study will allow continued mutation analysis in families with a history of TCS and should facilitate continued experimentation to shed further light on the function of the gene/protein during development of the craniofacial complex.
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Affiliation(s)
- J Dixon
- School of Biological Sciences, University of Manchester, UK
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32
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Roberts C, Daw SC, Halford S, Scambler PJ. Cloning and developmental expression analysis of chick Hira (Chira), a candidate gene for DiGeorge syndrome. Hum Mol Genet 1997; 6:237-45. [PMID: 9063744 DOI: 10.1093/hmg/6.2.237] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Deletions within human chromosome 22q11 cause a wide variety of birth defects including the DiGeorge syndrome and velo-cardio-facial (Shprintzen) syndrome. Despite the positional cloning of several genes from the critical region, it is still not possible to state whether the phenotype is secondary to haploinsufficiency of one or more than one gene. In embryological studies phenocopies of these abnormalities are produced by a variety of actions which disrupt the contribution made by the cranial and cardiac neural crest to development. The TUPLE1/HIRA gene is related to WD40 domain transcriptional regulators and maps within the DiGeorge critical region. We have cloned the chick homologue of HIRA and conducted in situ expression analysis in early chick embryos. Hira is expressed in the developing neural plate, the neural tube, neural crest and the mesenchyme of the head and branchial arch structures. HIRA may therefore have a role in the haploinsufficiency syndromes caused by deletion of 22q11.
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Affiliation(s)
- C Roberts
- Molecular Medicine Unit, Institute of Child Health, London, UK
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33
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Sutherland HF, Wadey R, McKie JM, Taylor C, Atif U, Johnstone KA, Halford S, Kim UJ, Goodship J, Baldini A, Scambler PJ. Identification of a novel transcript disrupted by a balanced translocation associated with DiGeorge syndrome. Am J Hum Genet 1996; 59:23-31. [PMID: 8659529 PMCID: PMC1915101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Most cases of DiGeorge syndrome (DGS) and related abnormalities are associated with deletions within 22q11. Shortest region of deletion overlap (SRO) mapping previously identified a critical region (the DGCR) of 500 kb, which was presumed to contain a gene or genes of major effect in the haploinsufficiency syndromes. The DGCR also contains sequences disrupted by a balanced translocation that is associated with DGS--the ADU breakpoint. We have cloned sequences at the breakpoint and screened for novel genes in its vicinity. A series of alternatively spliced transcripts expressed during human and murine embryogenesis, but with no obvious protein encoding potential, were identified. The gene encoding these RNAs has been named DGCR5 and it is disrupted by the patient ADU breakpoint. DGCR5 is distinct from the DGCR3 open reading frame (ORF) previously shown to be interrupted by the ADU translocation, although DGCR3 is embedded within a DGCR5 intron and in the same (predicted) transcriptional orientation. No mutations of DGCR5 have yet been detected. By analogy to other loci encoding conserved, nontranslated RNAs, it is possible that DGCR5 originates from a cis-acting transcriptional control element in the vicinity of the ADU/VDU breakpoint. Disruption of such an element would result in altered transcription of neighboring genes secondary to a position effect, a hypothesis in keeping with recent refinement of the SRO placing the ADU breakpoint outside the DGCR.
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Affiliation(s)
- H F Sutherland
- Molecular Medicine Unit, Institute of Child Health, London
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34
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Lindsay EA, Rizzu P, Antonacci R, Jurecic V, Delmas-Mata J, Lee CC, Kim UJ, Scambler PJ, Baldini A. A transcription map in the CATCH22 critical region: identification, mapping, and ordering of four novel transcripts expressed in heart. Genomics 1996; 32:104-12. [PMID: 8786095 DOI: 10.1006/geno.1996.0082] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The acronym CATCH22 is used to indicate collectively a group of related phenotypes, namely velocardiofacial syndrome (VCFS), DiGeorge anomaly (DGA), and conotruncal anomaly face, which are associated with deletions within 22q11.2 in the great majority of patients. A deletion map has allowed us to delimit a smallest region of deletion overlap, considerably smaller than the commonly deleted region. We have mapped within this region the chromosomal breakpoint of a balanced translocation patient presenting with a DGA/VCFS phenotype, making this region the strongest candidate for the location of the gene(s) responsible for the disease phenotype. We report a systematic gene search in this region and show the presence of at least six distinct transcripts, two of which have been previously described. The region searched was approximately 270 kb; therefore, an average of one transcript every 45 kb was found. We generated eight new ESTs and mapped two ESTs present in public databases. All six transcripts are expressed in heart, an organ involved in 70%-80% of CATCH22 patients. We show that the multimethod approach to search for expressed sequences is effective and indeed necessary for a comprehensive search and provides molecular tools for further characterization of the potential genes identified.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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35
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Hoyle J, Yulug IG, Johnstone K, Scambler PJ, Fisher EM. Characterisation of a short interspersed repeat (Mermaid) that has family members on human chromosome 21 and elsewhere in the human genome. Hum Genet 1996; 97:117-20. [PMID: 8557251 DOI: 10.1007/bf00218845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To understand the architecture of the human genome, we need a complete definition of all the repeat sequence families, as these make up the majority of human DNA. We have isolated a small DNA fragment from human chromosome 21 and have used sequence analysis of this fragment to uncover a new low copy repeat element of approximately 300 bp that we term the Mermaid repeat. This repeat is related to, but is different from, the MER12 repeat and is interspersed in the genome. Mermaid family members that we have studied are between 81%-87% identical to our preliminary consensus sequence. Therefore, we have added a new member to the large collection of human repetitive elements. In addition, we have mapped a Mermaid repeat to a telomeric position on the long arm of human chromosome 21, at 21q22.3.
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Affiliation(s)
- J Hoyle
- Department of Biochemistry and Molecular Genetics, St. Mary's Hospital Medical School, Imperial College, London, UK
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36
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Affiliation(s)
- J McKie
- Molecular Medicine Unit, Institute of Child Health, London, UK
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37
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Lindsay EA, Greenberg F, Shaffer LG, Shapira SK, Scambler PJ, Baldini A. Submicroscopic deletions at 22q11.2: variability of the clinical picture and delineation of a commonly deleted region. Am J Med Genet 1995; 56:191-7. [PMID: 7625444 DOI: 10.1002/ajmg.1320560216] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
DiGeorge anomaly (DGA) and velo-cardiofacial syndrome (VCFS) are frequently associated with monosomy of chromosome region 22q11. Most patients have a submicroscopic deletion, recently estimated to be at least 1-2 Mb. It is not clear whether individuals who present with only some of the features of these conditions have the deletion, and if so, whether the size of the deletion varies from those with more classic phenotypes. We have used fluorescence in situ hybridization (FISH) to assess the deletion status of 85 individuals referred to us for molecular analysis, with a wide range of DGA-like or VCFS-like clinical features. The test probe used was the cosmid sc11.1, which detects two loci about 2 Mb apart in 22q11.2. Twenty-four patients carried the deletion. Of the deleted patients, most had classic DGA or VCFS phenotypes, but 6 deleted patients had mild phenotypes, including 2 with minor facial anomalies and velopharyngeal incompetence as the only presenting signs. Despite the great phenotypic variability among the deleted patients, none had a deletion smaller than the 2-Mb region defined by sc11.1. Smaller deletions were not detected in patients with particularly suggestive phenotypes who were not deleted for sc11.1, even when tested with two other probes from the DGA/VCFS region.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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38
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Dixon J, Loftus SK, Gladwin AJ, Scambler PJ, Wasmuth JJ, Dixon MJ. Cloning of the human heparan sulfate-N-deacetylase/N-sulfotransferase gene from the Treacher Collins syndrome candidate region at 5q32-q33.1. Genomics 1995; 26:239-44. [PMID: 7601448 DOI: 10.1016/0888-7543(95)80206-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Treacher Collins syndrome is an autosomal dominant disorder of craniofacial development, the features of which include conductive hearing loss and cleft palate. Previous studies have shown that the Treacher Collins syndrome locus is flanked by D5S519 and SPARC, and a yeast artificial chromosome contig encompassing this "critical region" has been completed. In the current investigation a cosmid containing D5S519 has been used to screen a human placental cDNA library. This has resulted in the cloning of the human heparan sulfate-N-deacetylase/N-sulfotransferase gene. Two different mRNA species that have identical protein coding sequences but that differ in the size and sequence of the 3' untranslated regions (3' UTR) have been identified. The smaller species has a 3' UTR of 1035 bp, whereas that of the larger is 4878 bp.
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Affiliation(s)
- J Dixon
- School of Biological Sciences, University of Manchester, United Kingdom
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39
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Affiliation(s)
- S Halford
- Molecular Medicine Unit, Institute of Child Health, London, United Kingdom
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40
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Affiliation(s)
- M G Mattei
- U242, Physiopathologie Chromosomique, Faculte de Medicine, Marseille, France
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41
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Franke UC, Scambler PJ, Löffler C, Löns P, Hanefeld F, Zoll B, Hansmann I. Interstitial deletion of 22q11 in DiGeorge syndrome detected by high resolution and molecular analysis. Clin Genet 1994; 46:187-92. [PMID: 7820929 DOI: 10.1111/j.1399-0004.1994.tb04222.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two patients with DiGeorge syndrome (DGS), one with and one without characteristic dysmorphic facial features, were studied by high resolution banding, fluorescence in situ hybridization (FISH) and quantitative Southern blotting. In both patients, even in the one with no typical facial stigmata, a microdeletion within 22q11.2 was detected. FISH analysis, in particular, is most useful in screening for 22q11.2 segmental monosomy in patients with DGS and DGS-related features.
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Affiliation(s)
- U C Franke
- Institut für Humangenetik, Universität Göttingen, Germany
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42
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Scambler PJ. Report and abstracts of the Fourth International Workshop on Human Chromosome 22 mapping 1994. Cambridge, United Kingdom, July 2-4, 1994. Cytogenet Cell Genet 1994; 67:277-94. [PMID: 7924454 DOI: 10.1159/000133869] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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43
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Wadey R, Daw S, Wickremasinghe A, Roberts C, Wilson D, Goodship J, Burn J, Halford S, Scambler PJ. Isolation of a new marker and conserved sequences close to the DiGeorge syndrome marker HP500 (D22S134). J Med Genet 1993; 30:818-21. [PMID: 8230156 PMCID: PMC1016561 DOI: 10.1136/jmg.30.10.818] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
End fragment cloning from a YAC at the D22S134 locus allowed the isolation of a new probe HD7k. This marker detects hemizygosity in two patients previously shown to be dizygous for D22S134. This positions the distal deletion breakpoint in these patients to the sequences within the YAC, and confirms that HD7k is proximal to D22S134. In a search for coding sequences within the region commonly deleted in DGS we have identified a conserved sequence at D22S134. Although no cDNAs have yet been isolated, genomic sequencing shows a short open reading frame with weak similarity to collagen proteins.
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Affiliation(s)
- R Wadey
- Molecular Medicine Unit, Institute of Child Health, London, UK
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44
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Abstract
We report a mother and daughter with features of the velocardiofacial (VCF) syndrome and monosomy for 22q11 identified using molecular techniques. The mother had surgery as a child for a cleft palate and a congenital heart defect, and her facial features were consistent with the diagnosis. The daughter had developmental delay, absent speech, scoliosis, and similar facial features, but no cleft palate or congenital heart defect. These cases illustrate the considerable intrafamilial variability of the phenotype of VCF syndrome. The clinical and molecular diagnosis of this syndrome is discussed. The phenotypic variability of the VCF syndrome means that many cases may be undiagnosed.
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Affiliation(s)
- S E Holder
- Mothercare Unit of Clinical Genetics and Fetal Medicine, Institute of Child Health, London, UK
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45
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Lindsay EA, Halford S, Wadey R, Scambler PJ, Baldini A. Molecular cytogenetic characterization of the DiGeorge syndrome region using fluorescence in situ hybridization. Genomics 1993; 17:403-7. [PMID: 8406492 DOI: 10.1006/geno.1993.1339] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
DiGeorge syndrome (DGS) is a developmental defect characterized by cardiac defects, facial dysmorphism, and mental retardation. Several studies have described a critical region for DGS at 22q11, within which the majority of DGS patients have deletions. We have isolated nine cosmid and three YAC clones using previously described and newly isolated probes that have been shown to be deleted in many DGS patients. Using fluorescence in situ hybridization and digital imaging, we have mapped and ordered these clones relative to the breakpoints of two balanced translocations at 22q11 (one in a DGS patient and one in the unaffected parent of a DGS child). Our data indicate that the breakpoint in the unaffected individual distally limits the DGS critical region (defined as the smallest region of overlap), while proximally the region is limited by repeat-rich DNA. The critical region includes the balanced translocation breakpoint of the DGS patient that presumably disrupts the gene causing this syndrome.
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Affiliation(s)
- E A Lindsay
- Department of Biochemistry and Molecular Genetics, St. Mary's Hospital, London, United Kingdom
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46
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Abstract
Investigations into the genetic basis of DiGeorge syndrome have shown that in the majority of cases there are DNA deletions from the long arm of chromosome 22, at 22q11. Similar deletions are now known to be present in a wide range of conditions with overlapping clinical features, and are an important cause of familial congenital heart defect. Deletions within 22q11 have also been identified in individuals with no clinical complications.
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Affiliation(s)
- P J Scambler
- Molecular Medicine Unit, Institute of Child Health, London, UK
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47
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Wilkie AO, Taylor D, Scambler PJ, Baraitser M. Congenital cataract, microphthalmia and septal heart defect in two generations: a new syndrome? Clin Dysmorphol 1993; 2:114-9. [PMID: 8281271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The association of congenital cataracts, microphthalmia and heart disease is well recognized in fetal rubella, but genetic causes are comparatively rare and recurrence risks are usually low. We describe a woman with an atrial septal defect, bilateral congenital cataracts, unilateral microphthalmia and minor dysmorphic features, originally attributed to an unidentified infection in utero, whose daughter has a similar constellation of heart, eye and facial abnormalities. This may represent a new dominantly inherited syndrome.
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Affiliation(s)
- A O Wilkie
- Department of Paediatric Genetics, Hospital for Sick Children, London, UK
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48
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Abstract
A boy with the dysmorphic features of Noonan's syndrome and pulmonary valve stenosis who had evidence of hypoparathyroidism and abnormal T lymphocyte numbers in the neonatal period is reported. He had a normal karyotype but molecular analysis revealed a submicroscopic deletion within chromosome 22q11, the region deleted in DiGeorge syndrome. Thus this child has both Noonan's syndrome and DiGeorge syndrome; 22q11 is a candidate region for a gene defective in Noonan's syndrome.
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Affiliation(s)
- D I Wilson
- Department of Human Genetics, Newcastle upon Tyne
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49
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Kelly D, Goldberg R, Wilson D, Lindsay E, Carey A, Goodship J, Burn J, Cross I, Shprintzen RJ, Scambler PJ. Confirmation that the velo-cardio-facial syndrome is associated with haplo-insufficiency of genes at chromosome 22q11. Am J Med Genet 1993; 45:308-12. [PMID: 8434616 DOI: 10.1002/ajmg.1320450306] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The velo-cardio-facial syndrome (VCFS) and DiGeorge sequence (DGS) have many similar phenotypic characteristics, suggesting that in some cases they share a common cause. DGS is known to be associated with monosomy for a region of chromosome 22q11, and DNA probes have been shown to detect these deletions even in patients with apparently normal chromosomes. Twelve patients with VCFS were examined and monosomy for a region of 22q11 was found in all patients. The DNA probes used in this study could not distinguish the VCFS locus and the DGS locus, indicating that the genes involved in these haploinsufficiencies are closely linked, and may be identical. The phenotypic variation of expression in VCFS and DGS may indicate that patients without the full spectrum of VCFS abnormalities but with some manifestations of the disorder may also have 22q11 deletions.
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Affiliation(s)
- D Kelly
- Department of Biochemistry and Molecular Genetics, St. Mary's Hospital Medical School, London, United Kingdom
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50
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Halford S, Lindsay E, Nayudu M, Carey AH, Baldini A, Scambler PJ. Low-copy-number repeat sequences flank the DiGeorge/velo-cardio-facial syndrome loci at 22q11. Hum Mol Genet 1993; 2:191-6. [PMID: 8499906 DOI: 10.1093/hmg/2.2.191] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
DiGeorge syndrome and velo-cardio-facial syndrome are associated with deletions within 22q11. In attempting to refine the shortest region of overlap for these syndromes we have employed fluorescence in situ hybridisation. The results obtained for some probes indicate the presence of low-copy-number repeat families dispersed through proximal 22q. Several primate species have been examined for the presence or absence of two sequences mapping to pter-22q11. The results suggest a relatively recent evolutionary origin for these sequences and the loss of one sequence during the course of primate evolution.
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Affiliation(s)
- S Halford
- Department of Biochemistry and Molecular Genetics, St Mary's Hospital Medical School, London, UK
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