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4q25 Microdeletion with Axenfeld-Rieger Syndrome and Developmental Delay. Case Rep Genet 2023; 2023:4592114. [PMID: 36816813 PMCID: PMC9935865 DOI: 10.1155/2023/4592114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/11/2023] Open
Abstract
We encountered a case with congenital iris coloboma, omphalocele, and developmental delay with a 2.5 Mb deletion on chromosome 4q25 encompassing PITX2, leading to Axenfeld-Rieger syndrome (ARS), NEUROG2, and ANK2. ARS is characterized by the aplasia of the anterior eye, odontogenesis, and abdominal wall aplasia. In our case, iris coloboma and omphalocele were thought to be caused by PITX2 haploinsufficiency. However, these symptoms are nonspecific, and clinical symptoms alone can make it difficult to make a correct diagnosis. In addition, the genes responsible for developmental delay, among others, are not well understood. Developmental delay, in this case, might be caused due to NEUROG2 haploinsufficiency. In spite of the partial deletion of ANK2, the causative gene of long QT syndrome type 4, the electrocardiogram was normal. Genetic testing can lead to a correct diagnosis, and it may be effective in detecting complications.
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Yang Y, Wang X, Zhao Y, Qin M. A novel 4q25 microdeletion encompassing PITX2 associated with Rieger syndrome. Oral Dis 2018; 24:1247-1254. [PMID: 29774977 DOI: 10.1111/odi.12894] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 05/01/2018] [Accepted: 05/09/2018] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Rieger syndrome (RS) is a genetic disorder characterized by abnormal development of the eyes, teeth, and umbilicus, and the paired-like homeodomain 2 (PITX2) gene is often implicated in its pathogenesis. This study aimed to identify the underlying genetic defect in a Chinese patient with RS. SUBJECTS AND METHODS DNA samples were screened for PITX2 gene mutations and copy number variations (CNVs) using Sanger sequencing and genomic quantitative PCR analysis (qPCR). Chromosomal microarray analysis (CMA) was performed to fine-map the CNVs. RESULTS The proband suffered from severe hypodontia and conical teeth in her permanent dentition. No PITX2 point mutations were found in this Chinese family, but a heterozygous deletion involving PITX2 was suspected and verified by the SNPs analysis and qPCR in the proband. An approximately 0.47 Mb (chr4: 111, 334, 313-111, 799, 327, GRCh37/hg19) deletion including PITX2 was finally determined by CMA. CONCLUSIONS To our knowledge, this is the first reported case of RS caused by a CNV of the PITX2 gene in a Chinese patient. CNV screening must be considered if point mutation screens yield negative results in these patients. The distribution of SNP genotypes among family members may also provide clues about gene deletion.
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Affiliation(s)
- Yi Yang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xin Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yuming Zhao
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
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Vande Perre P, Zazo Seco C, Patat O, Bouneau L, Vigouroux A, Bourgeois D, El Hout S, Chassaing N, Calvas P. 4q25 microdeletion encompassing PITX2: A patient presenting with tetralogy of Fallot and dental anomalies without ocular features. Eur J Med Genet 2018; 61:72-78. [PMID: 29100920 DOI: 10.1016/j.ejmg.2017.10.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/07/2017] [Accepted: 10/29/2017] [Indexed: 12/19/2022]
Abstract
Axenfeld-Rieger syndrome (ARS) is a heterogeneous clinical entity transmitted in an autosomal dominant manner. The main feature, Axenfeld-Rieger Anomaly (ARA), is a malformation of the anterior segment of the eye that can lead to glaucoma and impair vision. Extra-ocular defects have also been reported. Point mutations of FOXC1 and PITX2 are responsible for about 40% of the ARS cases. We describe the phenotype of a patient carrying a deletion encompassing the 4q25 locus containing PITX2 gene. This child presented with a congenital heart defect (Tetralogy of Fallot, TOF) and no signs of ARA. He is the first patient described with TOF and a complete deletion of PITX2 (arr[GRCh37]4q25(110843057-112077858)x1, involving PITX2, EGF, ELOVL6 and ENPEP) inherited from his ARS affected mother. In addition, to our knowledge, he is the first patient reported with no ocular phenotype associated with haploinsufficiency of PITX2. We compare the phenotype and genotype of this patient to those of five other patients carrying 4q25 deletions. Two of these patients were enrolled in the university hospital in Toulouse, while the other three were already documented in DECIPHER. This comparative study suggests both an incomplete penetrance of the ocular malformation pattern in patients carrying PITX2 deletions and a putative association between TOF and PITX2 haploinsufficiency.
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Affiliation(s)
- P Vande Perre
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France; UDEAR, Université de Toulouse, UMRS 1056 Inserm-Université Paul Sabatier, Toulouse, France
| | - C Zazo Seco
- UDEAR, Université de Toulouse, UMRS 1056 Inserm-Université Paul Sabatier, Toulouse, France
| | - O Patat
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France; UDEAR, Université de Toulouse, UMRS 1056 Inserm-Université Paul Sabatier, Toulouse, France
| | - L Bouneau
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France
| | - A Vigouroux
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France
| | - D Bourgeois
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France
| | - S El Hout
- Service d'Ophtalmologie, Hôpital Purpan, CHU Toulouse, France
| | - N Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France; UDEAR, Université de Toulouse, UMRS 1056 Inserm-Université Paul Sabatier, Toulouse, France
| | - P Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, France; UDEAR, Université de Toulouse, UMRS 1056 Inserm-Université Paul Sabatier, Toulouse, France.
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Seifi M, Footz T, Taylor SAM, Elhady GM, Abdalla EM, Walter MA. Novel PITX2 gene mutations in patients with Axenfeld-Rieger syndrome. Acta Ophthalmol 2016; 94:e571-e579. [PMID: 27009473 DOI: 10.1111/aos.13030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 01/23/2016] [Indexed: 02/06/2023]
Abstract
PURPOSE Mutations in the bicoid-like transcription factor PITX2 gene often result in Axenfeld-Rieger syndrome (ARS), an autosomal-dominant inherited disorder. We report here the discovery and characterization of novel PITX2 deletions in a small kindred with ARS. METHODS Two familial patients (father and son) from a consanguineous family were examined in the present study. Patient DNA samples were screened for PITX2 mutations by DNA sequencing and for copy number variation by SYBR Green quantitative polymerase chain reaction (PCR) analysis. RESULTS We report a novel deletion involving the coding region of PITX2 in both patients. The minimum size of the deletion is 1 421 914 bp that spans one upstream regulatory element (CE4), PITX2 and a minimum of 13 neighbouring genes. The maximum size of the deletion is 3 789 983 bp. The proband (son) additionally possesses a novel 2-bp deletion in a non-coding exon of the remaining PITX2 allele predicted to alter correct splicing. CONCLUSION Our findings implicate a novel deletion of the PITX2 gene in the pathogenesis of ARS in the affected family. This ARS family presented with an atypical and extremely severe phenotype that resulted in four miscarriages and the death at 10 months of age of a sib of the proband. As the phenotypic manifestations in the proband are more severe than that of the father, we hypothesize that the deletion of the entire PITX2 allele plus a novel 2-bp deletion (observed in the proband) within the remaining PITX2 allele together contributed to the atypical ARS presentation in this family. This is the first study reporting on bi-allelic changes of PITX2 potentially contributing to a more severe ARS phenotype.
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Affiliation(s)
- Morteza Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Tim Footz
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Sherry A M Taylor
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ghada M Elhady
- Department of Human Genetics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Ebtesam M Abdalla
- Department of Human Genetics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Michael A Walter
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
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Titheradge H, Togneri F, McMullan D, Brueton L, Lim D, Williams D. Axenfeld-Rieger syndrome: further clinical and array delineation of four unrelated patients with a 4q25 microdeletion. Am J Med Genet A 2014; 164A:1695-701. [PMID: 24715413 DOI: 10.1002/ajmg.a.36540] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 02/14/2014] [Indexed: 11/06/2022]
Abstract
Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder with variable expressivity. It is characterized by dysgenesis of the anterior segment of the eye together with dental, cardiac, and umbilical anomalies. There is a high incidence of secondary high tension glaucoma. It is a genetically heterogeneous condition due to deletion or mutations of FOXC1 (6p25) or PITX2 (4q25). We report on four unrelated patients with overlapping microdeletions encompassing PITX2 at 4q25. We compare the genotypes and phenotypes of these newly described ARS patients and discuss the involvement of contiguous genes. Patients 1, 2, and 3 had mild learning difficulties, not typically seen in patients with ARS. We implicate the adjacent neuronally expressed genes; NEUROG2, UGT8, NDST3, and PRSS12 as potentially causal. Our findings support the use of microarray analysis in ARS patients for full prognostic information in infants presenting with ARS-like phenotypes.
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Affiliation(s)
- Hannah Titheradge
- Department of Clinical Genetics, Birmingham Women's NHS Foundation Trust, Birmingham, United Kingdom
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Verhoeven WM, Egger JI, Goffin L, van Zutven LJ, Mancini GM. Behavioural phenotype of a patient with a de novo 1.2 Mb chromosome 4q25 microdeletion. Eur J Med Genet 2013; 56:331-5. [DOI: 10.1016/j.ejmg.2013.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 03/11/2013] [Indexed: 11/27/2022]
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Derwińska K, Mierzewska H, Goszczańska A, Szczepanik E, Xia Z, Kuśmierska K, Tryfon J, Kutkowska-Kaźmierczak A, Bocian E, Mazurczak T, Obersztyn E, Stankiewicz P. Clinical improvement of the aggressive neurobehavioral phenotype in a patient with a deletion of PITX3 and the absence of L-DOPA in the cerebrospinal fluid. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:236-42. [PMID: 22223473 DOI: 10.1002/ajmg.b.32020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 12/09/2011] [Indexed: 11/07/2022]
Abstract
The development of midbrain dopamine (DA) neurons is regulated by several transcription factors, including Nurr1, Wnt1, Lmx1a/1b, En1, En2, Foxa1, Foxa2, and Pitx3. PITX3 is an upstream co-activator of the TH (tyrosine hydroxylase) promoter. Pitx3(-/-) mice have a selective loss of dopaminergic neurons in the substantia nigra and ventral tegmental area, leading to the significantly reduced DA levels in the nigrostriatal pathway and in the dorsal striatum and manifest anomalous striatum-dependent cognitive impairment and neurobehavioral activity. Treatment with L-DOPA, dopamine, or dopamine receptor agonists in these mice reversed several of their sensorimotor impairments. Heterozygous missense mutations in PITX3 have been reported in patients with autosomal dominant congenital cataract and anterior segment (ocular) mesenchymal dysgenesis (ASMD) whereas homozygous missense mutations have been found in patients with microphthalmia and neurological impairment. Using a clinical oligonucleotide array comparative genomic hybridization (aCGH), we have identified an ∼317 kb hemizygous deletion in 10q24.32, involving PITX3 in a 17-year-old male with a Smith-Magenis syndrome-like phenotype, including mild intellectual impairment, sleep disturbance, hyperactivity, and aggressive and self-destructive behavior. Interestingly, no eye anomalies were found in our patient. Analysis of neurotransmitters in his cerebrospinal fluid revealed an absence of L-DOPA and significantly decreased levels of catecholamine metabolites. Importantly, L-DOPA treatment of our patient has led to mild mitigation of his aggressive behavior and mild improvement of his attention span, extended time periods of concentration, and better sleep.
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Affiliation(s)
- Katarzyna Derwińska
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
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Oh TG, Chung JW, Kim HM, Han SJ, Lee JS, Park JY, Song SY. Primary intestinal lymphangiectasia diagnosed by capsule endoscopy and double balloon enteroscopy. World J Gastrointest Endosc 2011; 3:235-40. [PMID: 22110841 PMCID: PMC3221958 DOI: 10.4253/wjge.v3.i11.235] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 10/19/2011] [Accepted: 10/28/2011] [Indexed: 02/05/2023] Open
Abstract
Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy. Patients with PIL develop hypoalbuminemia, hypocalcemia, lymphopenia and hypogammaglobulinemia, and present with bilateral lower limb edema, fatigue, abdominal pain and diarrhea. Endoscopy reveals diffusely elongated, circumferential and polypoid mucosae covered with whitish enlarged villi, all of which indicate intestinal lymphangiectasia. Diagnosis is confirmed by characteristic tissue pathology, which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi. The prevalence of PIL has increased since the introduction of capsule endoscopy. The etiology and prevalence of PIL remain unknown. Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL. We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25. The relationship between this deletion on chromosome 4 and PIL remains to be investigated.
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Affiliation(s)
- Tak Geun Oh
- Tak Geun Oh, Joo Won Chung, Hee Man Kim, Jung Yeob Park, Si Young Song, Division of Gastroenterology, Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul 120-752, South Korea
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Kelberman D, Islam L, Holder SE, Jacques TS, Calvas P, Hennekam RC, Nischal KK, Sowden JC. Digenic inheritance of mutations in FOXC1 and PITX2 : correlating transcription factor function and Axenfeld-Rieger disease severity. Hum Mutat 2011; 32:1144-52. [PMID: 21837767 DOI: 10.1002/humu.21550] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 05/31/2011] [Indexed: 11/08/2022]
Abstract
Disease-causing mutations affecting either one of the transcription factor genes, PITX2 or FOXC1, have been previously identified in patients with Axenfeld-Rieger syndrome (AR). We identified a family who segregate novel mutations in both PITX2 (p.Ser233Leu) and FOXC1 (c.609delC). The most severely affected individual, who presented with an atypical phenotype of corneal opacification, lens extrusion, persistent hyperplastic primary vitreous (PHPV), and subsequent bilateral retinal detachment, inherited mutations in both genes, whereas the single heterozygous mutations caused mild AR phenotypes. This is the first report of such digenic inheritance. By analyzing cognate targets of each gene, we showed that FOXC1 and PITX2 can independently regulate their own and each other's target gene promoters and do not show synergistic action in vitro. Mutation in either gene caused reduced transcriptional activation to different extents on the FOXO1 and PLOD1 promoters, whereas both mutations in combination showed the lowest level of activation. These data show how the compensatory activity of one factor, when the other is impaired, may lessen the phenotypic impact of developmental anomalies, yet reduced activity of both transcription factors increased disease severity. This suggests an under-reported mechanism for phenotypic variability whereby single mutations cause mild AR phenotypes, whereas digenic inheritance increases phenotypic severity.
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Affiliation(s)
- Daniel Kelberman
- Ulverscroft Vision Research Group, UCL Institute of Child Health, London, United Kingdom
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Volkmann BA, Zinkevich NS, Mustonen A, Schilter KF, Bosenko DV, Reis LM, Broeckel U, Link BA, Semina EV. Potential novel mechanism for Axenfeld-Rieger syndrome: deletion of a distant region containing regulatory elements of PITX2. Invest Ophthalmol Vis Sci 2011; 52:1450-9. [PMID: 20881290 PMCID: PMC3101680 DOI: 10.1167/iovs.10-6060] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 08/23/2010] [Accepted: 09/07/2010] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Mutations in PITX2 are associated with Axenfeld-Rieger syndrome (ARS), which involves ocular, dental, and umbilical abnormalities. Identification of cis-regulatory elements of PITX2 is important to better understand the mechanisms of disease. METHODS Conserved noncoding elements surrounding PITX2/pitx2 were identified and examined through transgenic analysis in zebrafish; expression pattern was studied by in situ hybridization. Patient samples were screened for deletion/duplication of the PITX2 upstream region using arrays and probes. RESULTS Zebrafish pitx2 demonstrates conserved expression during ocular and craniofacial development. Thirteen conserved noncoding sequences positioned within a gene desert as far as 1.1 Mb upstream of the human PITX2 gene were identified; 11 have enhancer activities consistent with pitx2 expression. Ten elements mediated expression in the developing brain, four regions were active during eye formation, and two sequences were associated with craniofacial expression. One region, CE4, located approximately 111 kb upstream of PITX2, directed a complex pattern including expression in the developing eye and craniofacial region, the classic sites affected in ARS. Screening of ARS patients identified an approximately 7600-kb deletion that began 106 to 108 kb upstream of the PITX2 gene, leaving PITX2 intact while removing regulatory elements CE4 to CE13. CONCLUSIONS These data suggest the presence of a complex distant regulatory matrix within the gene desert located upstream of PITX2 with an essential role in its activity and provides a possible mechanism for the previous reports of ARS in patients with balanced translocations involving the 4q25 region upstream of PITX2 and the current patient with an upstream deletion.
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Affiliation(s)
- Bethany A. Volkmann
- From the Department of Pediatrics and Children's Research Institute and
- the Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | | | - Aki Mustonen
- the Department of Clinical Genetics, Oulu University Hospital, OYS, Finland
| | - Kala F. Schilter
- From the Department of Pediatrics and Children's Research Institute and
- the Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Dmitry V. Bosenko
- From the Department of Pediatrics and Children's Research Institute and
| | - Linda M. Reis
- From the Department of Pediatrics and Children's Research Institute and
| | - Ulrich Broeckel
- From the Department of Pediatrics and Children's Research Institute and
| | - Brian A. Link
- the Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Elena V. Semina
- From the Department of Pediatrics and Children's Research Institute and
- the Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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Tümer Z, Bach-Holm D. Axenfeld-Rieger syndrome and spectrum of PITX2 and FOXC1 mutations. Eur J Hum Genet 2009; 17:1527-39. [PMID: 19513095 PMCID: PMC2987033 DOI: 10.1038/ejhg.2009.93] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 01/23/2009] [Accepted: 03/17/2009] [Indexed: 01/09/2023] Open
Abstract
Axenfeld-Rieger syndrome (ARS) is a rare autosomal dominant disorder, which encompasses a range of congential malformations affecting the anterior segment of the eye. ARS shows genetic heterogeneity and mutations of the two genes, PITX2 and FOXC1, are known to be associated with the pathogenesis. There are several excellent reviews dealing with the complexity of the phenotype and genotype of ARS. In this study, we will attempt to give a brief review of the clinical features and the relevant diagnostic approaches, together with a detailed review of published PITX2 and FOXC1 mutations.
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Affiliation(s)
- Zeynep Tümer
- The Kennedy Center, Medical Genetics Laboratory, Glostrup, Denmark.
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