1
|
Liang B, Kong Y, Luo D, Wen H, Liao Y, Yuan Y, Li S. Prenatal ultrasound diagnosis of complete cryptophthalmos, congenital aphakia, and corneal vascularization in a fetus: A case report and literature review. Eur J Obstet Gynecol Reprod Biol 2024; 301:70-76. [PMID: 39106617 DOI: 10.1016/j.ejogrb.2024.07.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/27/2024] [Accepted: 07/31/2024] [Indexed: 08/09/2024]
Abstract
BACKGROUND Complete cryptophthalmos, congenital aphakia, and corneal vascularization are relatively uncommon congenital eye malformations during the fetal period. Herein, we report a case of a fetus with complete cryptophthalmos, congenital aphakia, and corneal vascularization in both eyes and review previous prenatal reports of related cases. CASE PRESENTATION The patient was a 27-year-old pregnant woman, gravida 2, para 1, who was referred to our hospital for consultation at 23 weeks of gestation due to a diagnosis of fetal right renal agenesis at an external hospital. The ultrasound system of our hospital diagnosed the fetus with complete cryptophthalmos, congenital aphakia, and corneal vascularization, which was verified under the postnatal water basin test, anatomical and pathological sections. CONCLUSIONS Fetal ocular malformations are often associated with malformations of other organs, and if ultrasound findings are associated with such malformations, attention should be paid to the ocular examination to avoid missing the diagnosis.
Collapse
Affiliation(s)
- Bocheng Liang
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Yanqing Kong
- Department of Pathology, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Dandan Luo
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Huaxuan Wen
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Yimei Liao
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Ying Yuan
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China
| | - Shengli Li
- Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen 518028, China.
| |
Collapse
|
2
|
Taneyhill LA, Hoover-Fong J, Lozanoff S, Marcucio R, Richtsmeier JT, Trainor PA. The society for craniofacial genetics and developmental biology 38th annual meeting. Am J Med Genet A 2016; 170:1732-53. [PMID: 27102868 DOI: 10.1002/ajmg.a.37651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 03/23/2016] [Indexed: 11/09/2022]
Abstract
The mission of the Society for Craniofacial Genetics and Developmental Biology (SCGDB) is to promote education, research, and communication about normal and abnormal development of the tissues and organs of the head. The SCGDB welcomes as members undergraduate students, graduate students, post doctoral researchers, clinicians, orthodontists, scientists, and academicians who share an interest in craniofacial biology. Each year our members come together to share their novel findings, build upon, and challenge current knowledge of craniofacial biology. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Lisa A Taneyhill
- Department of Animal and Avian Sciences, University of Maryland, 1405 Animal Sciences Center, College Park, Maryland
| | - Julie Hoover-Fong
- Greenberg Center for Skeletal Dysplasias, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Scott Lozanoff
- Department of Anatomy, Biochemistry & Physiology, University of Hawaii John A. Burns School of Medicine Honolulu, Hawaii
| | - Ralph Marcucio
- Department of Orthopaedic Surgery, University of California, San Francisco, California
| | - Joan T Richtsmeier
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri.,Department of Anatomy and Cell Biology, University of Kansas Medical Centre, Kansas City, Kansas
| |
Collapse
|
3
|
Pezzani L, Milani D, Manzoni F, Baccarin M, Silipigni R, Guerneri S, Esposito S. HOXA genes cluster: clinical implications of the smallest deletion. Ital J Pediatr 2015; 41:31. [PMID: 25881986 PMCID: PMC4395968 DOI: 10.1186/s13052-015-0137-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 03/31/2015] [Indexed: 01/16/2023] Open
Abstract
Background HOXA genes cluster plays a fundamental role in embryologic development. Deletion of the entire cluster is known to cause a clinically recognizable syndrome with mild developmental delay, characteristic facies, small feet with unusually short and big halluces, abnormal thumbs, and urogenital malformations. The clinical manifestations may vary with different ranges of deletions of HOXA cluster and flanking regions. Case presentation We report a girl with the smallest deletion reported to date involving the entire HOXA cluster at 7p15.2-p14.3. The patient was the third child born to a healthy and non-consanguineous Italian couple. She was born at the 34th week of gestation by caesarean section due to cholestasis of pregnancy. Her birth weight, length, and occipitofrontal circumference were 2,140 g (25-50th centile), 46 cm (50th centile), and 33 cm (75-90th centile), respectively. The Apgar scores were 8 at both the 1st and 5th minutes. The patient presented with typical mild facial anomalies, hand and feet abnormalities, urinary anomalies, and mild speech delay. Unexpectedly, the patient demonstrated complex unusual features of multiple episodes of oxyhemoglobin desaturation, laryngeal stridor and a branchial cyst. Chromosome analysis of the patient revealed an apparently normal karyotype at the 550 band level. Based on array comparative genomic hybridization, a 2.5 Mb interstitial deletion was detected at 7p15.2p14.3 (chr7: 26,333,553-28,859,312), involving the entire HOXA cluster and a small number of other genes as SNX10, SKAP2, EVX1, HIBADH, TAX1BP1, JAZF1, and CREB5. Conclusions This report improves our understanding of the genotype-phenotype correlations of HOXA genes cluster deletions via the identification and characterization of the smallest deletion (as well as critical region) reported to date. In particular we discuss the possible implications of preterm and haploinsufficiency in the pathogenesis of the unusual findings, furthermore opening new discussion and interpretation cues.
Collapse
Affiliation(s)
- Lidia Pezzani
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, Milan, 20122, Italy.
| | - Donatella Milani
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, Milan, 20122, Italy.
| | - Francesca Manzoni
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, Milan, 20122, Italy.
| | - Marco Baccarin
- Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
| | - Rosamaria Silipigni
- Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
| | - Silvana Guerneri
- Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
| | - Susanna Esposito
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, Milan, 20122, Italy.
| |
Collapse
|
4
|
Mauri L, Franzoni A, Scarcello M, Sala S, Garavelli L, Modugno A, Grammatico P, Patrosso MC, Piozzi E, Del Longo A, Gesu GP, Manfredini E, Primignani P, Damante G, Penco S. SOX2, OTX2 and PAX6 analysis in subjects with anophthalmia and microphthalmia. Eur J Med Genet 2014; 58:66-70. [PMID: 25542770 DOI: 10.1016/j.ejmg.2014.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 12/04/2014] [Indexed: 01/31/2023]
Abstract
Anophthalmia (A) and microphthalmia (M) are rare developmental anomalies that have significant effects on visual activity. In fraction of A/M subjects, single genetic defects have been identified as causative. In this study we analysed 65 Italian A/M patients, 21 of whom are syndromic, for mutations in SOX2, OTX2 and PAX6 genes. In syndromic patients the presence of genome imbalances through array CGH was also investigated. No mutations were found for OTX2 and PAX6 genes. Three causative SOX2 mutations were found in subjects with syndromic A. In a subject with syndromic signs and monolateral M, two de novo 6.26 Mb and 1.37 Mb deletions in 4q13.2q13.3 have been identified. A SOX2 missense (p.Ala161Ser) mutation was found in 1 out of 39 a subject with non-syndromic monolateral M. Alanine at position 161 is conserved along phylogeny and the p.Ala161Ser mutation is estimated pathogenic by in silico analysis. However, this mutation was also present in the unaffected patient's daughter.
Collapse
Affiliation(s)
- Lucia Mauri
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Alessandra Franzoni
- Institute of Genetics, Azienda Ospedaliero-Universitaria Udine, Udine, Italy
| | - Manuela Scarcello
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Stefano Sala
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Livia Garavelli
- Clinical Genetics Unit, IRCCS Arcispedale S. Maria Nuova, Reggio Emilia, Italy
| | | | - Paola Grammatico
- Department of Molecular Medicine, "La Sapienza" University, Rome, Italy
| | - Maria Cristina Patrosso
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Elena Piozzi
- Pediatric Ophthalmology, Niguarda Ca' Granda Hospital, Milan, Italy
| | | | - Giovanni P Gesu
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Emanuela Manfredini
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Paola Primignani
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Giuseppe Damante
- Institute of Genetics, Azienda Ospedaliero-Universitaria Udine, Udine, Italy; Department of Medical and Biological Sciences, Udine University, Udine, Italy.
| | - Silvana Penco
- Department of Laboratory Medicine, Medical Genetics, Niguarda Ca' Granda Hospital, Milan, Italy.
| |
Collapse
|
5
|
Hosoki K, Ohta T, Fujita K, Nishigaki S, Shiomi M, Niikawa N, Saitoh S. Hand-foot-genital syndrome with a 7p15 deletion: clinically recognizable syndrome. Pediatr Int 2012; 54:e22-5. [PMID: 22631585 DOI: 10.1111/j.1442-200x.2011.03550.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Kana Hosoki
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | | | | | | | | | | | | |
Collapse
|
6
|
Spaggiari E, Aboura A, Sinico M, Mabboux P, Dupont C, Delezoide AL, Guimiot F. Prenatal diagnosis of a 7p15-p21 deletion encompassing the TWIST1 gene involved in Saethre-Chotzen syndrome. Eur J Med Genet 2012; 55:498-501. [PMID: 22569119 DOI: 10.1016/j.ejmg.2012.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 04/20/2012] [Indexed: 11/28/2022]
Abstract
Saethre-Chotzen syndrome is a craniosynostosis syndrome that is rarely diagnosed prenatally. It is caused by cytogenetic deletions or mutations of the TWIST1 gene. We report here a de novo prenatal case with clinically and molecularly well defined Saethre-Chotzen syndrome due to a TWIST1 deletion. This is the first reported case of a deletion encompassing the TWIST1 gene to be diagnosed prenatally. We recommend screening for a deletion of the TWIST1 gene if signs of coronal craniosynostosis with no clear etiology are observed on ultrasound examination.
Collapse
Affiliation(s)
- Emmanuel Spaggiari
- Department of Developmental Biology, AP-HP, Robert Debré Hospital, 48, Boulevard Sérurier, 75019 Paris, France
| | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
PURPOSE OF REVIEW To summarize recent breakthroughs regarding the genes known to play a role in normal ocular development in humans and to elucidate the role mutations in these genes play in anophthalmia and microphthalmia. RECENT FINDINGS The main themes discussed within this article are the various documented genetic advances in identifying the various causes of anophthalmia and microphthalmia. In addition, the complex interplay of these genes during critical embryonic development will be addressed. SUMMARY The recent identification of many eye development genes has changed the ability to identify a cause of anophthalmia and microphthalmia in many individuals. Syndrome identification and the availability of genetic testing underscores the desirability of evaluation by a geneticist for all individuals with anophthalmia and microphthalmia in order to provide appropriate management, long-term guidance, and genetic counseling.
Collapse
|
8
|
Fryssira H, Makrythanasis P, Kattamis A, Stokidis K, Menten B, Kosaki K, Willems P, Kanavakis E. Severe Developmental Delay in a Patient with 7p21.1-p14.3 Microdeletion Spanning the TWIST Gene and the HOXA Gene Cluster. Mol Syndromol 2011; 2:45-49. [PMID: 22570644 DOI: 10.1159/000334313] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2011] [Indexed: 11/19/2022] Open
Abstract
We describe a patient with a rare interstitial deletion of chromosome 7p21.1-p14.3 detected by array-CGH. The deletion encompassed 74 genes and caused haploinsufficiency (or loss of allele) of 6 genes known to be implicated in different autosomal dominant genetic disorders: TWIST, DFNA5, CYCS, HOXA11, HOXA13, and GARS. The patient had several morphological abnormalities similar to Saethre-Chotzen syndrome (caused by TWIST mutations) including craniosynostosis of the coronal suture and anomalies similar to those seen in hand-foot-uterus syndrome (caused by HOXA13 mutations) including hypospadias. The combined phenotype of Saethre-Chotzen syndrome and hand-foot-uterus syndrome of our patient closely resembles a previously reported case with a cytogenetically visible small deletion spanning 7p21-p14.3. We therefore conclude that microdeletions of 7p spanning the TWIST gene and HOXA gene cluster lead to a clinically recognizable 'haploinsufficiency syndrome'.
Collapse
Affiliation(s)
- H Fryssira
- Department of Medical Genetics, University of Athens Medical School, Choremio Research Laboratory, 'Aghia Sophia' Children's Hospital, Athens, Greece
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Jun KR, Seo EJ, Lee JO, Yoo HW, Park IS, Yoon HK. Molecular cytogenetic and clinical characterization of a patient with a 5.6-Mb deletion in 7p15 including HOXA cluster. Am J Med Genet A 2011; 155A:642-7. [DOI: 10.1002/ajmg.a.33860] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 11/29/2010] [Indexed: 11/06/2022]
|
10
|
Kouassi FX, Koffi KV, Safede K, Cochard C, Cochener B. [Congenital anophthalmias: a case of trisomy 13]. J Fr Ophtalmol 2006; 29:e10. [PMID: 16885798 DOI: 10.1016/s0181-5512(06)77708-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Congenital anophthalmia is the result of a lack of development or regression of the primary optic vesicle in utero. It can be isolated or associated with other malformations and can be unilateral or, rarely, bilateral. Different etiologies are usually found such as chromosomal aberrations, gene mutations, toxic agents, and infections. We report a case of bilateral congenital anophthalmia in a setting of a polymalformative syndrome with microcephalia and bilateral lip cleft. Karyotype studies confirmed trisomy 13 known as Patau's syndrome. Trisomy 13 is a rare lethal chromosomal aberration frequently responsible for uni- or bilateral microphthalmia and occasionally for anophthalmia.
Collapse
Affiliation(s)
- F X Kouassi
- Service d'Ophtalmologie, CHU de Cocody, Abidjan, Côte-d'Ivoire.
| | | | | | | | | |
Collapse
|
11
|
Ting JC, Ye Y, Thomas GH, Ruczinski I, Pevsner J. Analysis and visualization of chromosomal abnormalities in SNP data with SNPscan. BMC Bioinformatics 2006; 7:25. [PMID: 16420694 PMCID: PMC1382255 DOI: 10.1186/1471-2105-7-25] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 01/18/2006] [Indexed: 11/25/2022] Open
Abstract
Background A variety of diseases are caused by chromosomal abnormalities such as aneuploidies (having an abnormal number of chromosomes), microdeletions, microduplications, and uniparental disomy. High density single nucleotide polymorphism (SNP) microarrays provide information on chromosomal copy number changes, as well as genotype (heterozygosity and homozygosity). SNP array studies generate multiple types of data for each SNP site, some with more than 100,000 SNPs represented on each array. The identification of different classes of anomalies within SNP data has been challenging. Results We have developed SNPscan, a web-accessible tool to analyze and visualize high density SNP data. It enables researchers (1) to visually and quantitatively assess the quality of user-generated SNP data relative to a benchmark data set derived from a control population, (2) to display SNP intensity and allelic call data in order to detect chromosomal copy number anomalies (duplications and deletions), (3) to display uniparental isodisomy based on loss of heterozygosity (LOH) across genomic regions, (4) to compare paired samples (e.g. tumor and normal), and (5) to generate a file type for viewing SNP data in the University of California, Santa Cruz (UCSC) Human Genome Browser. SNPscan accepts data exported from Affymetrix Copy Number Analysis Tool as its input. We validated SNPscan using data generated from patients with known deletions, duplications, and uniparental disomy. We also inspected previously generated SNP data from 90 apparently normal individuals from the Centre d'Étude du Polymorphisme Humain (CEPH) collection, and identified three cases of uniparental isodisomy, four females having an apparently mosaic X chromosome, two mislabelled SNP data sets, and one microdeletion on chromosome 2 with mosaicism from an apparently normal female. These previously unrecognized abnormalities were all detected using SNPscan. The microdeletion was independently confirmed by fluorescence in situ hybridization, and a region of homozygosity in a UPD case was confirmed by sequencing of genomic DNA. Conclusion SNPscan is useful to identify chromosomal abnormalities based on SNP intensity (such as chromosomal copy number changes) and heterozygosity data (including regions of LOH and some cases of UPD). The program and source code are available at the SNPscan website .
Collapse
Affiliation(s)
- Jason C Ting
- Department of Neurology, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA
| | - Ying Ye
- Pathobiology Graduate Program, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - George H Thomas
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
- Department of Genetics, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA
| | - Ingo Ruczinski
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
| | - Jonathan Pevsner
- Department of Neurology, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA
- Pathobiology Graduate Program, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| |
Collapse
|
12
|
Bell SM, Schreiner CM, Waclaw RR, Campbell K, Potter SS, Scott WJ. Sp8 is crucial for limb outgrowth and neuropore closure. Proc Natl Acad Sci U S A 2003; 100:12195-200. [PMID: 14526104 PMCID: PMC218735 DOI: 10.1073/pnas.2134310100] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2003] [Indexed: 11/18/2022] Open
Abstract
In this report we describe the developmental expression and function of Sp8, a member of the Sp family of zinc finger transcription factors, and provide evidence that the legless transgene insertional mutant is a hypomorphic allele of the Sp8 gene. Sp8 is expressed during embryogenesis in the forming apical ectodermal ridge (AER), restricted regions of the central nervous system, and tail bud. Targeted deletion of the Sp8 gene gives a striking phenotype, with severe truncation of both forelimbs and hindlimbs, absent tail, as well as defects in anterior and posterior neuropore closure leading to exencephaly and spina bifida. Outgrowth of the limb depends on formation of the AER, a signaling center that forms at the limb bud apex. In Sp8 mutants, the AER precursor cells are induced and initially express multiple appropriate marker genes, but expression of these genes is not maintained and progression to a mature AER is blocked. These observations indicate that Sp8 functions downstream of Wnt3, Fgf10, and Bmpr1a in the signaling cascade that mediates AER formation.
Collapse
Affiliation(s)
- Sheila M Bell
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
| | | | | | | | | | | |
Collapse
|
13
|
Cai J, Goodman BK, Patel AS, Mulliken JB, Van Maldergem L, Hoganson GE, Paznekas WA, Ben-Neriah Z, Sheffer R, Cunningham ML, Daentl DL, Jabs EW. Increased risk for developmental delay in Saethre-Chotzen syndrome is associated with TWIST deletions: an improved strategy for TWIST mutation screening. Hum Genet 2003; 114:68-76. [PMID: 14513358 DOI: 10.1007/s00439-003-1012-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2003] [Accepted: 07/18/2003] [Indexed: 11/30/2022]
Abstract
The majority of patients with Saethre-Chotzen syndrome have mutations in the TWIST gene, which codes for a basic helix-loop-helix transcription factor. Of the genetic alterations identified in TWIST, nonsense mutations, frameshifts secondary to small deletions or insertions, and large deletions implicate haploinsufficiency as the pathogenic mechanism. We identified three novel intragenic mutations and six deletions in our patients by using a new strategy to screen for TWIST mutations. We used polymerase chain reaction (PCR) amplification with subsequent sequencing to identify point mutations and small insertions or deletions in the coding region, and real-time PCR-based gene dosage analysis to identify large deletions encompassing the gene, with confirmation by microsatellite and fluorescence in situ hybridization (FISH) analyses. The size of the deletions can also be analyzed by using the gene dosage assay with "PCR walking" across the critical region. In 55 patients with features of Saethre-Chotzen syndrome, 11% were detected to have deletions by real-time gene dosage analysis. Two patients had a translocation or inversion at least 260 kb 3' of the gene, suggesting they had position-effect mutations. Of the 37 patients with classic features of Saethre-Chotzen syndrome, the overall detection rate for TWIST mutations was 68%. The risk for developmental delay in patients with deletions involving the TWIST gene is approximately 90% or eight times more common than in patients with intragenic mutations.
Collapse
Affiliation(s)
- Juanliang Cai
- Department of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|