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Maas NMC, Van de Putte T, Melotte C, Francis A, Schrander-Stumpel CTRM, Sanlaville D, Genevieve D, Lyonnet S, Dimitrov B, Devriendt K, Fryns JP, Vermeesch JR. The C20orf133 gene is disrupted in a patient with Kabuki syndrome. BMJ Case Rep 2009; 2009:bcr06.2009.1994. [PMID: 21720541 DOI: 10.1136/bcr.06.2009.1994] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Kabuki syndrome (KS) is a rare, congenital mental retardation syndrome. The aetiology of KS remains unknown. Four carefully selected patients with KS were screened for chromosomal imbalances using array comparative genomic hybridisation at 1 Mb resolution. In one patient, a 250 kb de novo microdeletion at 20p12.1 was detected, deleting exon 5 of C20orf133. The function of this gene is unknown. In situ hybridisation with the mouse orthologue of C20orf133 showed expression mainly in brain. The de novo nature of the deletion, the expression data and the fact that C20orf133 carries a macro domain, suggesting a role for the gene in chromatin biology, make the gene a likely candidate to cause the phenotype in this patient with KS. Both the finding of different of chromosomal rearrangements in patients with KS features and the absence of C20orf133 mutations in 19 additional patients with KS suggest that KS is genetically heterogeneous.
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177
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Nitsch D, Tranchevent LC, Thienpont B, Thorrez L, Van Esch H, Devriendt K, Moreau Y. Network analysis of differential expression for the identification of disease-causing genes. PLoS One 2009; 4:e5526. [PMID: 19436755 PMCID: PMC2677677 DOI: 10.1371/journal.pone.0005526] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 04/20/2009] [Indexed: 02/08/2023] Open
Abstract
Genetic studies (in particular linkage and association studies) identify chromosomal regions involved in a disease or phenotype of interest, but those regions often contain many candidate genes, only a few of which can be followed-up for biological validation. Recently, computational methods to identify (prioritize) the most promising candidates within a region have been proposed, but they are usually not applicable to cases where little is known about the phenotype (no or few confirmed disease genes, fragmentary understanding of the biological cascades involved). We seek to overcome this limitation by replacing knowledge about the biological process by experimental data on differential gene expression between affected and healthy individuals. Considering the problem from the perspective of a gene/protein network, we assess a candidate gene by considering the level of differential expression in its neighborhood under the assumption that strong candidates will tend to be surrounded by differentially expressed neighbors. We define a notion of soft neighborhood where each gene is given a contributing weight, which decreases with the distance from the candidate gene on the protein network. To account for multiple paths between genes, we define the distance using the Laplacian exponential diffusion kernel. We score candidates by aggregating the differential expression of neighbors weighted as a function of distance. Through a randomization procedure, we rank candidates by p-values. We illustrate our approach on four monogenic diseases and successfully prioritize the known disease causing genes.
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178
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Carey JC, Cohen MM, Curry CJR, Devriendt K, Holmes LB, Verloes A. Elements of morphology: standard terminology for the lips, mouth, and oral region. Am J Med Genet A 2009; 149A:77-92. [PMID: 19125428 DOI: 10.1002/ajmg.a.32602] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An international group of clinicians and scientists working in the field of dysmorphology has initiated the standardization of terms used to describe human morphology. The goals are to standardize these terms and reach consensus regarding their definitions. In this way, we will increase the utility of descriptions of the human phenotype and facilitate reliable comparisons of findings among patients. Discussions with other workers in dysmorphology and related fields, such as developmental biology and molecular genetics, will become more precise. Here we summarize the anatomy of the oral region and define and illustrate the terms that describe the major characteristics of the lips and mouth.
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179
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Proesmans W, Van Dyck M, Devriendt K. Nail-patella syndrome, infantile nephrotic syndrome: complete remission with antiproteinuric treatment. Nephrol Dial Transplant 2008; 24:1335-8. [DOI: 10.1093/ndt/gfn725] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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180
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Buysse K, Crepel A, Menten B, Pattyn F, Antonacci F, Veltman JA, Larsen LA, Tümer Z, de Klein A, van de Laar I, Devriendt K, Mortier G, Speleman F. Mapping of 5q35 chromosomal rearrangements within a genomically unstable region. J Med Genet 2008; 45:672-8. [PMID: 18628311 DOI: 10.1136/jmg.2008.058883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Recent molecular studies of breakpoints of recurrent chromosome rearrangements revealed the role of genomic architecture in their formation. In particular, segmental duplications representing blocks of >1 kb with >90% sequence homology were shown to mediate non-allelic homologous recombination (NAHR). However, the occurrence of the majority of newly detected submicroscopic imbalances cannot be explained by the presence of segmental duplications. Therefore, further studies are needed to investigate whether architectural features other than segmental duplications mediate these rearrangements. METHODS We analysed a series of patients with breakpoints clustering within chromosome band 5q35. Using high density arrays and subsequent quantitative polymerase chain reaction (qPCR), we characterised the breakpoints of four interstitial deletions (including one associated with an unbalanced paracentric inversion), a duplication and a familial reciprocal t(5;18)(q35;q22) translocation. RESULTS AND CONCLUSION Five of the breakpoints were located within an interval of approximately 265 kb encompassing the RANBP17 and TLX3 genes. This region is also targeted by the recurrent cryptic t(5;14)(q35;q32) translocation, which occurs in approximately 20% of childhood T cell acute lymphoblastic leukaemia (T-ALL). In silico analysis indicated the architectural features most likely to contribute to the genomic instability of this region, which was supported by our molecular data. Of further interest, in two patients and the familial translocation, the delineated breakpoint regions encompassed highly homologous LINEs (long interspersed nuclear elements), suggesting that NAHR between these LINEs may have mediated these rearrangements.
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181
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Casteels I, Casaer P, Gewillig M, Swillen A, Devriendt K. Ocular findings in children with a microdeletion in chromosome 22q11.2. Eur J Pediatr 2008; 167:751-5. [PMID: 17704945 DOI: 10.1007/s00431-007-0582-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 07/09/2007] [Accepted: 07/11/2007] [Indexed: 10/22/2022]
Abstract
A microdeletion in chromosome 22q11.2 is one of the most frequent genetic syndromes. The phenotypic manifestations vary widely, which has led to its initial description as apparently different clinical entities, such as the velocardiofacial syndrome (VCFS) and DiGeorge syndrome. Characteristic features include cleft palate, conotruncal heart malformations, thymus hypoplasia, hypoparathyroidism, a characteristic facial phenotype and learning difficulties. Ocular abnormalities are frequently seen in this patient population. We describe the ophthalmological findings in 36 children between the age of 3 and 14 years with a microdeletion in chromosome 22q11.2. They underwent a full ophthalmological examination with assessment of visual acuity, eye position and motility, stereoscopic vision, biomicroscopic examination, refraction and fundoscopy. If necessary amblyopia treatment was started and follow-up was planned. The presence of a cardiovascular malformation was noted. In conclusion, refractive errors, strabismus, amblyopia and structural ocular abnormalities are frequently encountered in children with a microdeletion in chromosome 22q11.2. Ophthalmological examination at a young age and refractive correction in those children is warranted. On the other hand, ocular findings can give a clue to the diagnosis of del 22q11.2.
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182
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Hannes FD, Sharp AJ, Mefford HC, de Ravel T, Ruivenkamp CA, Breuning MH, Fryns JP, Devriendt K, Van Buggenhout G, Vogels A, Stewart H, Hennekam RC, Cooper GM, Regan R, Knight SJL, Eichler EE, Vermeesch JR. Recurrent reciprocal deletions and duplications of 16p13.11: the deletion is a risk factor for MR/MCA while the duplication may be a rare benign variant. J Med Genet 2008; 46:223-32. [PMID: 18550696 PMCID: PMC2658752 DOI: 10.1136/jmg.2007.055202] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Genomic disorders are often caused by non-allelic homologous recombination between segmental duplications. Chromosome 16 is especially rich in a chromosome-specific low copy repeat, termed LCR16. METHODS AND RESULTS A bacterial artificial chromosome (BAC) array comparative genome hybridisation (CGH) screen of 1027 patients with mental retardation and/or multiple congenital anomalies (MR/MCA) was performed. The BAC array CGH screen identified five patients with deletions and five with apparently reciprocal duplications of 16p13 covering 1.65 Mb, including 15 RefSeq genes. In addition, three atypical rearrangements overlapping or flanking this region were found. Fine mapping by high-resolution oligonucleotide arrays suggests that these deletions and duplications result from non-allelic homologous recombination (NAHR) between distinct LCR16 subunits with >99% sequence identity. Deletions and duplications were either de novo or inherited from unaffected parents. To determine whether these imbalances are associated with the MR/MCA phenotype or whether they might be benign variants, a population of 2014 normal controls was screened. The absence of deletions in the control population showed that 16p13.11 deletions are significantly associated with MR/MCA (p = 0.0048). Despite phenotypic variability, common features were identified: three patients with deletions presented with MR, microcephaly and epilepsy (two of these had also short stature), and two other deletion carriers ascertained prenatally presented with cleft lip and midline defects. In contrast to its previous association with autism, the duplication seems to be a common variant in the population (5/1682, 0.29%). CONCLUSION These findings indicate that deletions inherited from clinically normal parents are likely to be causal for the patients' phenotype whereas the role of duplications (de novo or inherited) in the phenotype remains uncertain. This difference in knowledge regarding the clinical relevance of the deletion and the duplication causes a paradigm shift in (cyto)genetic counselling.
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183
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Swinnen S, Bailleul-Forestier I, Arte S, Nieminen P, Devriendt K, Carels C. Investigating the etiology of multiple tooth agenesis in three sisters with severe oligodontia. Orthod Craniofac Res 2008; 11:24-31. [PMID: 18199077 DOI: 10.1111/j.1601-6343.2008.00410.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To describe the dentofacial phenotypes of three sisters with severe non-syndromic oligodontia, to report on the mutation analysis in three genes, previously shown to cause various phenotypes of non-syndromic oligodontia and in two other suspected genes. Based on the phenotypes in the pedigree of this family, the different possible patterns of transmission are discussed. METHODS Anamnestic data and a panoramic radiograph were taken to study the phenotype of the three sisters and their first-degree relatives. Blood samples were also taken to obtain their karyotypes and DNA samples. Mutational screening was performed for the MSX1, PAX9, AXIN2, DLX1 and DLX2 genes. RESULTS The probands' pedigree showed evidence for a recessive or multifactorial inheritance pattern. Normal chromosomal karyotypes were found and - despite the severe oligodontia present in all three sisters - no mutation appeared to be present in the five genes studied so far in these patients. CONCLUSIONS In the three sisters reported, their common oligodontia phenotype is not caused by mutations in the coding regions of MSX1, PAX9, AXIN2, DLX1 or DLX2 genes, but genetic factors most probably play a role as all three sisters were affected. Environmental and epigenetic factors as well as genes regulating odontogenesis need further in vivo and in vitro investigation to explain the phenotypic heterogeneity and to increase our understanding of the odontogenic processes.
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184
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Rauch A, Thiel CT, Schindler D, Wick U, Crow YJ, Ekici AB, van Essen AJ, Goecke TO, Al-Gazali L, Chrzanowska KH, Zweier C, Brunner HG, Becker K, Curry CJ, Dallapiccola B, Devriendt K, Dorfler A, Kinning E, Megarbane A, Meinecke P, Semple RK, Spranger S, Toutain A, Trembath RC, Voss E, Wilson L, Hennekam R, de Zegher F, Dorr HG, Reis A. Mutations in the Pericentrin (PCNT) Gene Cause Primordial Dwarfism. Science 2008; 319:816-9. [DOI: 10.1126/science.1151174] [Citation(s) in RCA: 316] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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185
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Van de Laar I, Dooijes D, Hoefsloot L, Simon M, Hoogeboom J, Devriendt K. Limb anomalies in patients with CHARGE syndrome: an expansion of the phenotype. Am J Med Genet A 2008; 143A:2712-5. [PMID: 17937444 DOI: 10.1002/ajmg.a.32008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
CHARGE syndrome is characterized by a wide clinical variability. During the past years the phenotypic spectrum was markedly expanded. Limb anomalies were initially not recognized as part of the phenotype but more recently mild limb anomalies were described in approximately 30% of the patients. We report on three patients with several major features of CHARGE syndrome who, in addition, presented severe limb anomalies including monodactyly, tibia aplasia, and bifid femora. Three different heterozygous truncating mutations in the CHD7 gene were detected. It has been hypothesized before that the CHARGE syndrome is caused by a disruption of mesenchymal-epithelial interaction. Given the expression of the CHD7 gene in the developing limb bud, it was anticipated that limb defects would belong to the spectrum of manifestations of CHARGE syndrome. The present observations provide further support to this hypothesis.
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186
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Callewaert B, Willaert A, Kerstjens-Frederikse W, De Backer J, Devriendt K, Albrecht B, Ramos-Arroyo M, Doco-Fenzy M, Hennekam R, Pyeritz R, Krogmann O, Gillessen-kaesbach G, Wakeling E, Nik-zainal S, Francannet C, Mauran P, Booth C, Barrow M, Dekens R, Loeys B, Coucke P, De Paepe A. Arterial tortuosity syndrome: clinical and molecular findings in 12 newly identified families. Hum Mutat 2008; 29:150-8. [DOI: 10.1002/humu.20623] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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187
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Witters I, Balikova I, Cannie M, Devriendt K, De Catte L, Fryns JP. Lobar holoprosencephaly in 18pter deletion resulting from the karyotype 45,X,-18,der(8;18)t(8; 18)(pter;p11.21). GENETIC COUNSELING (GENEVA, SWITZERLAND) 2008; 19:443-446. [PMID: 19239091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
MESH Headings
- Abnormalities, Multiple/genetics
- Centromere/genetics
- Chromosome Deletion
- Chromosomes, Human, Pair 18/genetics
- Chromosomes, Human, Pair 8/genetics
- Chromosomes, Human, X/genetics
- Cleft Lip/genetics
- Cleft Palate/genetics
- Female
- Frontal Lobe/abnormalities
- Frontal Lobe/pathology
- Holoprosencephaly/genetics
- Humans
- In Situ Hybridization, Fluorescence
- Karyotyping
- Magnetic Resonance Imaging
- Pregnancy
- Pregnancy Trimester, Second
- Prenatal Diagnosis
- Sex Chromosome Aberrations
- Translocation, Genetic/genetics
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188
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De Smedt B, Swillen A, Devriendt K, Fryns JP, Verschaffel L, Boets B, Ghesquière P. Cognitive correlates of mathematical disabilities in children with velo-cardio-facial syndrome. GENETIC COUNSELING (GENEVA, SWITZERLAND) 2008; 19:71-94. [PMID: 18564504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Children with Velo-Cardio-Facial Syndrome (VCFS) consistently show mathematical disabilities (MD). At the neuropsychological level, it is important to know which general cognitive deficits underlie these MD. Therefore, we examined various mathematical abilities, working memory, rapid automatized naming and processing speed in 25 children with VCFS and 25 carefully selected matched controls. Children with VCFS showed a reduced ability to solve addition and subtraction problems and performed less accurately on multidigit arithmetic and word problem solving. There were no group differences on the general cognitive measures, except that children with VCFS performed higher than controls on the phonological loop tasks. To conclude, the administered general cognitive competencies could not give a satisfactory account of the MD in VCFS.
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189
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Maas NMC, Van Buggenhout G, Hannes F, Thienpont B, Sanlaville D, Kok K, Midro A, Andrieux J, Anderlid BM, Schoumans J, Hordijk R, Devriendt K, Fryns JP, Vermeesch JR. Genotype-phenotype correlation in 21 patients with Wolf-Hirschhorn syndrome using high resolution array comparative genome hybridisation (CGH). J Med Genet 2007; 45:71-80. [PMID: 17873117 DOI: 10.1136/jmg.2007.052910] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND The Wolf-Hirschhorn syndrome (WHS) is usually caused by terminal deletions of the short arm of chromosome 4 and is phenotypically defined by growth and mental retardation, seizures, and specific craniofacial manifestations. Large variation is observed in phenotypic expression of these features. In order to compare the phenotype with the genotype, we localised the breakpoints of the 4 pter aberrations using a chromosome 4 specific tiling BAC/PAC array. METHODS In total, DNA from 21 patients was analysed, of which 8 had a cytogenetic visible and 13 a submicroscopic deletion. RESULTS AND CONCLUSION In addition to classical terminal deletions sized between 1.9 and 30 Mb, we observed the smallest terminal deletion (1.4 Mb) ever reported in a patient with mild WHS stigmata. In addition, we identified and mapped interstitial deletions in four patients. This study positions the genes causing microcephaly, intrauterine and postnatal growth retardation between 0.3 and 1.4 Mb and further refines the regions causing congenital heart disease, cleft lip and/or palate, oligodontia, and hypospadias.
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190
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Witters I, Debois P, Fryns JP, Devriendt K, Gewillig M. A case of left isomerism with early fetal decompensation. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 30:363-4. [PMID: 17663484 DOI: 10.1002/uog.4069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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191
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De Smedt B, Devriendt K, Fryns JP, Vogels A, Gewillig M, Swillen A. Intellectual abilities in a large sample of children with Velo-Cardio-Facial Syndrome: an update. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2007; 51:666-70. [PMID: 17845235 DOI: 10.1111/j.1365-2788.2007.00955.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
BACKGROUND Learning disabilities are one of the most consistently reported features in Velo-Cardio-Facial Syndrome (VCFS). Earlier reports on IQ in children with VCFS were, however, limited by small sample sizes and ascertainment biases. The aim of the present study was therefore to replicate these earlier findings and to investigate intellectual abilities in a large sample of children with VCFS. In addition, we aimed to identify factors that may contribute to within-syndrome variability in cognitive performance, such as the mode of inheritance of the deletion, sex, the presence of a heart defect and psychiatric morbidity. METHOD IQ data of 103 children with VCFS (56 males, 47 females) were collected. Psychiatric diagnosis was additionally recorded. RESULTS Children with VCFS had a mean full-scale IQ (FSIQ) of 73.48 (range: 50-109). There were no effects of sex, presence of a heart defect and psychiatric condition on intellectual profile. Inheritance of the deletion affected cognitive performance in VCFS, with children with familial deletions having significant lower FSIQ than children with a de novo deletion. CONCLUSIONS Learning disabilities are very common in children with VCFS, although marked within syndrome variability is noted. One factor contributing to this variability seems to be the mode of inheritance of the deletion.
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192
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Lu W, Quintero-Rivera F, Fan Y, Alkuraya FS, Donovan DJ, Xi Q, Turbe-Doan A, Li QG, Campbell CG, Shanske AL, Sherr EH, Ahmad A, Peters R, Rilliet B, Parvex P, Bassuk AG, Harris DJ, Ferguson H, Kelly C, Walsh CA, Gronostajski RM, Devriendt K, Higgins A, Ligon AH, Quade BJ, Morton CC, Gusella JF, Maas RL. NFIA haploinsufficiency is associated with a CNS malformation syndrome and urinary tract defects. PLoS Genet 2007; 3:e80. [PMID: 17530927 PMCID: PMC1877820 DOI: 10.1371/journal.pgen.0030080] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Accepted: 04/05/2007] [Indexed: 11/23/2022] Open
Abstract
Complex central nervous system (CNS) malformations frequently coexist with other developmental abnormalities, but whether the associated defects share a common genetic basis is often unclear. We describe five individuals who share phenotypically related CNS malformations and in some cases urinary tract defects, and also haploinsufficiency for the NFIA transcription factor gene due to chromosomal translocation or deletion. Two individuals have balanced translocations that disrupt NFIA. A third individual and two half-siblings in an unrelated family have interstitial microdeletions that include NFIA. All five individuals exhibit similar CNS malformations consisting of a thin, hypoplastic, or absent corpus callosum, and hydrocephalus or ventriculomegaly. The majority of these individuals also exhibit Chiari type I malformation, tethered spinal cord, and urinary tract defects that include vesicoureteral reflux. Other genes are also broken or deleted in all five individuals, and may contribute to the phenotype. However, the only common genetic defect is NFIA haploinsufficiency. In addition, previous analyses of Nfia−/− knockout mice indicate that Nfia deficiency also results in hydrocephalus and agenesis of the corpus callosum. Further investigation of the mouse Nfia+/− and Nfia−/− phenotypes now reveals that, at reduced penetrance, Nfia is also required in a dosage-sensitive manner for ureteral and renal development. Nfia is expressed in the developing ureter and metanephric mesenchyme, and Nfia+/− and Nfia−/− mice exhibit abnormalities of the ureteropelvic and ureterovesical junctions, as well as bifid and megaureter. Collectively, the mouse Nfia mutant phenotype and the common features among these five human cases indicate that NFIA haploinsufficiency contributes to a novel human CNS malformation syndrome that can also include ureteral and renal defects. Central nervous system (CNS) and urinary tract abnormalities are common human malformations, but their variability and genetic complexity make it difficult to identify the responsible genes. Analysis of human chromosomal abnormalities associated with such disorders offers one approach to this problem. In five individuals described herein, a novel human syndrome that involves both CNS and urinary tract defects is associated with chromosomal disruption or deletion of NFIA, encoding a member of the Nuclear Factor I (NFI) family of transcription factors. This syndrome includes brain abnormalities (abnormal corpus callosum, hydrocephalus, ventriculomegaly, and Chiari type I malformation), spinal abnormalities (tethered spinal cord), and urinary tract abnormalities (vesicoureteral reflux). Nfia disruption in mice was already known to cause hydrocephalus and abnormal corpus callosum, and is now shown to exhibit renal defects and disturbed ureteral development. Other genes besides NFIA are also disrupted or deleted and may contribute to the observed phenotype. However, loss of one copy of NFIA is the only genetic defect common to all five patients. The authors thus provide evidence that genetic loss of NFIA contributes to a distinct CNS malformation syndrome with urinary tract defects of variable penetrance.
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193
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Maas NMC, Van de Putte T, Melotte C, Francis A, Schrander-Stumpel CTRM, Sanlaville D, Genevieve D, Lyonnet S, Dimitrov B, Devriendt K, Fryns JP, Vermeesch JR. The C20orf133 gene is disrupted in a patient with Kabuki syndrome. J Med Genet 2007; 44:562-9. [PMID: 17586838 PMCID: PMC2597955 DOI: 10.1136/jmg.2007.049510] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Kabuki syndrome (KS) is a rare, clinically recognisable, congenital mental retardation syndrome. The aetiology of KS remains unknown. METHODS Four carefully selected patients with KS were screened for chromosomal imbalances using array comparative genomic hybridisation at 1 Mb resolution. RESULTS In one patient, a 250 kb de novo microdeletion at 20p12.1 was detected, deleting exon 5 of C20orf133. The function of this gene is unknown. In situ hybridisation with the mouse orthologue of C20orf133 showed expression mainly in brain, but also in kidney, eye, inner ear, ganglia of the peripheral nervous system and lung. CONCLUSION The de novo nature of the deletion, the expression data and the fact that C20orf133 carries a macro domain, suggesting a role for the gene in chromatin biology, make the gene a likely candidate to cause the phenotype in this patient with KS. Both the finding of different of chromosomal rearrangements in patients with KS features and the absence of C20orf133 mutations in 19 additional patients with KS suggest that KS is genetically heterogeneous.
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MESH Headings
- Abnormalities, Multiple/genetics
- Amino Acid Sequence
- Animals
- Chromosomes, Human, Pair 20/chemistry
- Chromosomes, Human, Pair 20/genetics
- Chromosomes, Human, Pair 20/ultrastructure
- DNA Repair Enzymes
- Exons/genetics
- Face/abnormalities
- Female
- Gene Expression Regulation, Developmental
- Humans
- Hydrolases
- Infant, Newborn
- Intellectual Disability/genetics
- Membrane Glycoproteins
- Membrane Proteins/genetics
- Mice
- Molecular Sequence Data
- Nucleic Acid Hybridization
- Organ Specificity
- Phenotype
- Sequence Alignment
- Sequence Deletion
- Sequence Homology, Amino Acid
- Syndrome
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/physiology
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Witters I, Cannie M, Casaer P, Devriendt K, Fryns JP. Prenatal diagnosis of schizencephaly after inhalation of organic solvents. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 29:356-7. [PMID: 17323304 DOI: 10.1002/uog.3939] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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195
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Maas NMC, Van Vooren S, Hannes F, Van Buggenhout G, Mysliwiec M, Moreau Y, Fagan K, Midro A, Engiz O, Balci S, Parker MJ, Sznajer Y, Devriendt K, Fryns JP, Vermeesch JR. The t(4;8) is mediated by homologous recombination between olfactory receptor gene clusters, but other 4p16 translocations occur at random. GENETIC COUNSELING (GENEVA, SWITZERLAND) 2007; 18:357-365. [PMID: 18286816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The t(4;8)(p16;p23) is the second most common constitutional chromosomal translocation and is caused by an ectopic meiotic recombination between the olfactory receptor gene clusters (ORGC), located on chromosome 4p and 8p. Given that ORGCs are scattered across the genome and make-up about 0.1% of the human genome we reasoned that translocations between 4p16 and other chromosomes might be mediated by ectopic recombination between different ORGC. In 13 patients, we mapped the breakpoints of either a balanced or unbalanced translocation between chromosome 4p16 and different chromosomes. For all four t(4;8) cases, the breakpoints fall within the 4p and 8pter ORGC, confirming that non-allelic homologous recombination (NAHR) between the ORGC is the main mechanism of the t(4;8) formation. For the nine other translocations, the breakpoints on chromosome 4 mapped to different loci, one of them within the ORGC and in two flanking the ORGC. In these three cases, the translocation breakpoint at the reciprocal chromosome did not contain ORGC sequences. We conclude that only the t(4;8) is mediated by NAHR between ORGC.
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Majava M, Hoornaert KP, Bartholdi D, Bouma MC, Bouman K, Carrera M, Devriendt K, Hurst J, Kitsos G, Niedrist D, Petersen MB, Shears D, Stolte-Dijkstra I, Van Hagen JM, Ala-Kokko L, Männikkö M, Mortier GR. A report on 10 new patients with heterozygous mutations in theCOL11A1 gene and a review of genotype–phenotype correlations in type XI collagenopathies. Am J Med Genet A 2007; 143A:258-64. [PMID: 17236192 DOI: 10.1002/ajmg.a.31586] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A series of 44 unrelated patients in whom COL2A1 screening demonstrated normal results but whose phenotype was nevertheless highly suggestive of either Stickler syndrome (with ocular involvement) or Marshall syndrome were investigated for mutations in the COL11A1 gene. Heterozygous COL11A1 mutations were found in 10 individuals. A splice site alteration (involving introns 47-55) was present in seven cases, with one in intron 50 (c.3816 + 1G > A) occurring in three patients. Two patients had a different deletion, and a missense mutation (Gly1471Asp) was observed in one case. In 4/10 patients the phenotype was classified as Marshall syndrome because of early-onset severe hearing loss and characteristic facial features. These four patients were all heterozygous for a splice site mutation in intron 50. One of these cases had a type 1 vitreous anomaly despite the presence of a COL11A1 mutation. The remaining 6/10 patients had an overlapping Marshall-Stickler phenotype with less pronounced facial features. None of these had a mutation in the hot spot region of intron 50.
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197
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De Smedt B, Swillen A, Devriendt K, Fryns JP, Verschaffel L, Ghesquière P. Mathematical disabilities in children with velo-cardio-facial syndrome. Neuropsychologia 2007; 45:885-95. [PMID: 17049567 DOI: 10.1016/j.neuropsychologia.2006.08.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Revised: 07/14/2006] [Accepted: 08/25/2006] [Indexed: 11/17/2022]
Abstract
Current neurocognitive theories of number processing [Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003). Three parietal circuits for number processing. Cognitive Neuropsychology, 20, 487-506] state that mathematical performance is made possible by two functionally and anatomically distinct subsystems of number processing: a verbal system located in the angular gyrus, which underlies the retrieval of arithmetic facts, and a quantity system located in the intraparietal sulcus, which subserves operations that involve semantic manipulations of quantity. According to this model, subtypes of math disability (MD) should be traceable to differential impairments in these subsystems. The present study investigated MD in children with velo-cardio-facial syndrome (VCFS) and aimed to verify which of these subsystems of number processing is impaired in these children. Eleven children with VCFS and 11 individually matched controls, selected from the same classes, completed a large battery of mathematical tests. Our data revealed that children with VCFS had preserved number reading abilities and preserved retrieval of arithmetic facts, both of which indicate that the verbal subsystem is not impaired in VCFS. By contrast, children with VCFS showed difficulties in number comparison, the execution of a calculation strategy and word problem solving, all of which involve the semantic manipulation of quantities. This provides evidence for a specific deficit in the quantity subsystem in children with VCFS, suggesting underlying abnormalities in the intraparietal sulcus.
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198
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de Ravel TJL, Balikova I, Thienpont B, Hannes F, Maas N, Fryns JP, Devriendt K, Vermeesch JR. Molecular karyotyping of patients with MCA/MR: the blurred boundary between normal and pathogenic variation. Cytogenet Genome Res 2006; 115:225-30. [PMID: 17124404 DOI: 10.1159/000095918] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2006] [Accepted: 05/02/2006] [Indexed: 11/19/2022] Open
Abstract
Molecular karyotyping has revealed that microdeletions/duplications in the human genome are a major cause of multiple congenital anomalies associated with mental retardation (MCA/MR). The identification of a de novo chromosomal imbalance in a patient with MCA/MR is usually considered causal for the phenotype while a chromosomal imbalance inherited from a phenotypically normal parent is considered as a benign variation and not related to the disorder. Around 40% of imbalances in patients with MCA/MR in this series is inherited from a healthy parent and the majority of these appear to be (extremely) rare variants. As some of these contain known disease-causing genes and have also been found to be de novo in MCA/MR patients, this challenges the general view that such familial variants are innocent and of no major phenotypic consequence. Rather, we argue, that human genomes can be tolerant of genomic copy number variations depending on the genetic and environmental background and that different mechanisms play a role in determining whether these chromosomal imbalances manifest themselves.
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199
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Thienpont B, Gewillig M, Fryns JP, Devriendt K, Vermeesch J. Molecular cytogenetic characterization of a constitutional complex intrachromosomal 4q rearrangement in a patient with multiple congenital anomalies. Cytogenet Genome Res 2006; 114:338-41. [PMID: 16954676 DOI: 10.1159/000094223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Accepted: 01/09/2006] [Indexed: 01/07/2023] Open
Abstract
Constitutional Complex Chromosomal Rearrangements (CCRs) are very rare. While the vast majority of CCRs involve more than one chromosome, only seven cases describe CCRs with four or more breakpoints within a single chromosome. Here, we present a patient with multiple congenital anomalies and mental retardation. Array Comparative Genomic Hybridisation (array CGH), FISH and Multicolour Banding FISH revealed a de novo complex rearrangement with two deletions, a duplication and an inversion of 4q. This CCR involving at least seven breakpoints is one of the most complex rearrangements of a single chromosome reported thus far. Potential mechanisms generating such complex rearrangements are discussed.
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Lambrechts D, Devriendt K, Driscoll DA, Goldmuntz E, Gewillig M, Vlietinck R, Collen D, Carmeliet P. Low expression VEGF haplotype increases the risk for tetralogy of Fallot: a family based association study. J Med Genet 2006; 42:519-22. [PMID: 15937089 PMCID: PMC1736071 DOI: 10.1136/jmg.2004.026443] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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