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Kahl N, Lüsebrink N, Schubert-Bast S, Freiman TM, Kieslich M. Bilateral Foramina Parietalia Permagna - A Calvarial Defect Caused by Haploinsufficiency of the Msh Homeobox 2 Gene: A Case Report and Current Literature Review. Neuropediatrics 2024; 55:205-208. [PMID: 38447947 DOI: 10.1055/s-0044-1781465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Foramina parietalia permagna (FPP) is a rare anatomical defect that affects the parietal bones of the human skull. FPP is characterized by symmetric perforations on either side of the skull, which are caused by insufficient ossification during embryogenesis. These openings are typically abnormally large and can range from a few millimeters to several centimeters in diameter. Enlarged foramina are often discovered incidentally during anatomical or radiological examinations and in most cases left untreated unless symptoms develop. Although this calvarial defect is usually asymptomatic, it may be accompanied by neurological or vascular conditions that can have clinical significance in certain cases. FPP is an inherited disorder and arises due to mutations in either Msh homeobox 2 (MSX2) or aristaless-like homeobox 4 (ALX4) genes. In almost all cases, one parent is affected. Clinical findings and diagnostic imaging typically contribute to determine the diagnosis.
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Affiliation(s)
- Niklas Kahl
- Division of Neurology, Neurometabolics and Prevention, Department of Pediatrics, Goethe University Frankfurt, Frankfurt, Germany
| | - Natalia Lüsebrink
- Division of Neurology, Neurometabolics and Prevention, Department of Pediatrics, Goethe University Frankfurt, Frankfurt, Germany
| | - Susanne Schubert-Bast
- Division of Neurology, Neurometabolics and Prevention, Department of Pediatrics, Goethe University Frankfurt, Frankfurt, Germany
| | - Thomas M Freiman
- Department of Neurosurgery, Rostock University Medical Center, Rostock, Germany
| | - Matthias Kieslich
- Division of Neurology, Neurometabolics and Prevention, Department of Pediatrics, Goethe University Frankfurt, Frankfurt, Germany
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2
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Kock KH, Kimes PK, Gisselbrecht SS, Inukai S, Phanor SK, Anderson JT, Ramakrishnan G, Lipper CH, Song D, Kurland JV, Rogers JM, Jeong R, Blacklow SC, Irizarry RA, Bulyk ML. DNA binding analysis of rare variants in homeodomains reveals homeodomain specificity-determining residues. Nat Commun 2024; 15:3110. [PMID: 38600112 PMCID: PMC11006913 DOI: 10.1038/s41467-024-47396-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 03/29/2024] [Indexed: 04/12/2024] Open
Abstract
Homeodomains (HDs) are the second largest class of DNA binding domains (DBDs) among eukaryotic sequence-specific transcription factors (TFs) and are the TF structural class with the largest number of disease-associated mutations in the Human Gene Mutation Database (HGMD). Despite numerous structural studies and large-scale analyses of HD DNA binding specificity, HD-DNA recognition is still not fully understood. Here, we analyze 92 human HD mutants, including disease-associated variants and variants of uncertain significance (VUS), for their effects on DNA binding activity. Many of the variants alter DNA binding affinity and/or specificity. Detailed biochemical analysis and structural modeling identifies 14 previously unknown specificity-determining positions, 5 of which do not contact DNA. The same missense substitution at analogous positions within different HDs often exhibits different effects on DNA binding activity. Variant effect prediction tools perform moderately well in distinguishing variants with altered DNA binding affinity, but poorly in identifying those with altered binding specificity. Our results highlight the need for biochemical assays of TF coding variants and prioritize dozens of variants for further investigations into their pathogenicity and the development of clinical diagnostics and precision therapies.
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Affiliation(s)
- Kian Hong Kock
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
- Program in Biological and Biomedical Sciences, Harvard University, Cambridge, MA, USA
| | - Patrick K Kimes
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Stephen S Gisselbrecht
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - Sachi Inukai
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - Sabrina K Phanor
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - James T Anderson
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - Gayatri Ramakrishnan
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
- Boston Bangalore Biosciences Beginnings Program, Harvard University, Cambridge, MA, USA
| | - Colin H Lipper
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Dongyuan Song
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jesse V Kurland
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
| | - Julia M Rogers
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
- Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA, USA
| | - Raehoon Jeong
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA
- Bioinformatics and Integrative Genomics Graduate Program, Harvard University, Cambridge, MA, USA
| | - Stephen C Blacklow
- Program in Biological and Biomedical Sciences, Harvard University, Cambridge, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA, USA
| | - Rafael A Irizarry
- Department of Data Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA.
- Program in Biological and Biomedical Sciences, Harvard University, Cambridge, MA, USA.
- Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA, USA.
- Bioinformatics and Integrative Genomics Graduate Program, Harvard University, Cambridge, MA, USA.
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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3
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Peled A, Sarig O, Mohamad J, Eskin-Schwartz M, Vodo D, Bochner R, Malchin N, Isakov O, Shomron N, Fainberg G, Bertolini M, Paus R, Sprecher E. Dominant frontonasal dysplasia with ectodermal defects results from increased activity of ALX4. Am J Med Genet A 2023; 191:2806-2812. [PMID: 37724761 DOI: 10.1002/ajmg.a.63408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/18/2023] [Accepted: 09/05/2023] [Indexed: 09/21/2023]
Abstract
Frontonasal dysplasia (FND) refers to a group of rare developmental disorders characterized by abnormal morphology of the craniofacial region. We studied a family manifesting with clinical features typical for FND2 including neurobehavioral abnormalities, hypotrichosis, hypodontia, and facial dysmorphism. Whole-exome sequencing analysis identified a novel heterozygous frameshift insertion in ALX4 (c.985_986insGTGC, p.Pro329Argfs*115), encoding aristaless homeobox 4. This and a previously reported dominant FND2-causing variant are predicted to result in the formation of a similar abnormally elongated protein tail domain. Using a reporter assay, we showed that the elongated ALX4 displays increased activity. ALX4 negatively regulates the Wnt/β-catenin pathway and accordingly, patient keratinocytes showed altered expression of genes associated with the WNT/β-catenin pathway, which in turn may underlie ectodermal manifestations in FND2. In conclusion, dominant FND2 with ectodermal dysplasia results from frameshift variants in ALX4 exerting a gain-of-function effect.
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Affiliation(s)
- Alon Peled
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Ofer Sarig
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Janan Mohamad
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv, Israel
| | - Marina Eskin-Schwartz
- Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva, Israel
- Soroka University Medical Center, Genetic Institute, Be'er Sheva, Israel
| | - Dan Vodo
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Ron Bochner
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Natalya Malchin
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Ofer Isakov
- Rabin Medical Center, Raphael Recanati Genetic Institute, Petach Tikva, Israel
- Clalit Research Institute, Clalit Health Services, Ramat Gan, Israel
- The Ivan and Francesca Berkowitz Family Living Laboratory Collaboration at Harvard Medical School and Clalit Research Institute, Boston, Massachusetts, USA
| | - Noam Shomron
- Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv, Israel
| | - Gilad Fainberg
- Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Marta Bertolini
- Department of Dermatology, University of Münster, Münster, Germany
- Monasterium Laboratory, Nano-Bioanalytik Zentrum, Münster, Germany
| | - Ralf Paus
- Monasterium Laboratory, Nano-Bioanalytik Zentrum, Münster, Germany
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Florida, USA
- Centre for Dermatology Research, Institute of Inflammation and Repair, University of Manchester, Manchester, UK
| | - Eli Sprecher
- Division of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv, Israel
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Vargel I, Canter HI, Kucukguven A, Aydin A, Ozgur F. ALX-Related Frontonasal Dysplasias: Clinical Characteristics and Surgical Management. Cleft Palate Craniofac J 2021; 59:637-643. [PMID: 34098755 DOI: 10.1177/10556656211019621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AIM The term frontonasal dysplasia (FND) represents a spectrum of anomalies and its genetics have not been well defined. Recently, the critical role of the aristaless-like homeobox (ALX) gene family on the craniofacial development has been discovered. In the present study, we aimed to propose a systematic surgical treatment plan for the ALX-related FNDs according to the genotypic classification as well as demonstrating their clinical characteristics to help surgeons diagnose the underlying pathology accurately. DESIGN Single-institution retrospective. SETTING Tertiary health care. PATIENTS AND METHODS Eighty-nine FND cases were evaluated. Eight of them had ALX1-related FND3, 3 had ALX3-related FND1, and 2 had ALX4-related FND2. Phenotype characteristics of ALX-related FNDs were evaluated, and relevant surgical interventions were assessed. RESULTS The ALX1-related FND3 phenotype is striking due to the involvement of the eyes in addition to the presence of hypertelorism, facial clefts, and nasal deformities. A widened philtrum and prominent philtral columns are remarkable features of the ALX3-related FND1, whereas the ALX4-related FND2 has more severe deformities: severe hypertelorism, brachycephaly, large parietal bone defects, broad nasal dorsum, and alopecia. Facial bipartition, box osteotomies, eyelid coloboma repair, cleft lip and palate repair, nasal reconstruction, and fronto-orbital advancement can be performed in ALX-related FNDs based on the characteristics of each subtype. CONCLUSIONS This genetic classification system will help surgeon diagnose patients with FND with unique features and draw a roadmap for their treatment with a better surgical perspective.
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Affiliation(s)
- Ibrahim Vargel
- 37515Hacettepe University Faculty of Medicine, Department of Plastic, Reconstructive and Aesthetic Surgery, Ankara, Turkey
| | - Halil Ibrahim Canter
- 356435Anadolu Medical Center, Department of Plastic and Reconstructive Surgery, Istanbul, Turkey
| | - Arda Kucukguven
- 37515Hacettepe University Faculty of Medicine, Department of Plastic, Reconstructive and Aesthetic Surgery, Ankara, Turkey
| | - Asim Aydin
- 52994Suleyman Demirel University Faculty of Medicine, Department of Plastic, Reconstructive and Aesthetic Surgery, Isparta, Turkey
| | - Figen Ozgur
- 37515Hacettepe University Faculty of Medicine, Department of Plastic, Reconstructive and Aesthetic Surgery, Ankara, Turkey
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Chen CH, Bournat JC, Wilken N, Rosenfeld JA, Zhang J, Seth A, Jorgez CJ. Variants in ALX4 and their association with genitourinary defects. Andrology 2020; 8:1243-1255. [PMID: 32385972 DOI: 10.1111/andr.12815] [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: 03/14/2019] [Revised: 04/28/2020] [Accepted: 05/05/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Genitourinary anomalies occur in approximately 1% of humans, but in most cases, the cause is unknown. Aristaless-like homeobox 4 (ALX4) is an important homeodomain transcription factor. ALX4 mutations in humans and mouse have been associated with craniofacial defects and genitourinary anomalies such as cryptorchidism and epispadias. OBJECTIVES To investigate the presence and the functional impact of ALX4 variants in patients with genitourinary defects. MATERIALS AND METHODS Two separate patient cohorts were analyzed. One includes clinical exome-sequencing (ES) data from 7500 individuals. The other includes 52 ALX4 Sanger-sequenced individuals with bladder exstrophy-epispadias complex (BEEC). Dual luciferase assays were conducted to investigate the functional transcriptional impact of ALX4 variants in HeLa cells and HEK293 cells. RESULTS A total of 41 distinct ALX4 heterozygous missense variants were identified in the ES cohort with 15 variants present as recurrent in multiple patients. p.G369E and p.L373F were the only two present in individuals with genitourinary defects. A p.L373F heterozygous variant was also identified in one of the 52 individuals in the BEEC cohort. p.L373F and p.G369E were tested in vitro as both are considered damaging by MutationTaster, although only p.G369E was considered damaging by PolyPhen-2. p.L373F did not alter transcriptional activity in HeLa and HEK293 cells. p.G369E caused a significant 3.4- and 1.8-fold decrease in transcriptional activities relative to wild-type ALX4 in HEK293 and HeLa cells, respectively. DISCUSSION AND CONCLUSIONS Our study supports the idea that transcription factors like ALX4 could influence the normal development of the GU tract in humans as demonstrated in mouse models as ALX4 variant p.G369E (predicted pathogenic by multiple databases) affects ALX4 function in vitro. Variant p.L373F (predicted pathogenic by only MutationTaster) did not affect ALX4 function in vitro. Exon-sequence information and mouse genetics provide important insights into the complex mechanisms driving genitourinary defects allowing the association of transcriptional defects with congenital disorders.
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Affiliation(s)
- Ching H Chen
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Juan C Bournat
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Nathan Wilken
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA.,Department of Urology, Baylor College of Medicine, Houston, TX, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratories, Baylor College of Medicine, Houston, TX, USA
| | - Jason Zhang
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Abhishek Seth
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA.,Department of Urology, Baylor College of Medicine, Houston, TX, USA.,Division of Urology, Department of Surgery, Texas Children's Hospital, Houston, TX, USA
| | - Carolina J Jorgez
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, USA.,Department of Urology, Baylor College of Medicine, Houston, TX, USA.,Division of Urology, Department of Surgery, Texas Children's Hospital, Houston, TX, USA
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6
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Hussain S, Umm-E-Kalsoom, Ullah I, Liaqat K, Nawaz S, Ahmad W. A Novel Missense Variant in the ALX4 Gene Underlies Mild to Severe Frontonasal Dysplasia in a Consanguineous Family. Genet Test Mol Biomarkers 2020; 24:217-223. [PMID: 32216639 DOI: 10.1089/gtmb.2019.0203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background: Frontonasal dysplasia (FND) is a rare developmental disorder characterized by mild to severe changes in skull and brain structures. It is a phenotypically variable and heterogeneous disorder. This study was designed to provide a clinical and genetic analysis of FND in a consanguineous family of Pakistani origin. Methodology and Results: Affected individuals in the family showed characteristic features of frontonasal dysplasia type-2 (FND2), such as nasal bone hypoplasia, hypertelorism, and alopecia. Skull and brain imaging of affected members revealed ossification defects and various types of brain structural anomalies that created a split-brain. Sanger sequencing of the ALX4 gene revealed a homozygous missense variant [NM_021926.4: c.652C>T; p.(Arg218Trp)] in three affected members who demonstrated severe craniofacial anomalies. Heterozygous carriers in the family showed mild FND2 phenotypes. Conclusion: Clinical and genetic analysis of a family, exhibiting FND2 phenotypes, revealed several previously unreported clinical features and a novel missense variant in the ALX4 gene. These results will facilitate diagnosis and genetic counseling of the FND patients in the Pakistani population.
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Affiliation(s)
- Shabir Hussain
- Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan
| | - Umm-E-Kalsoom
- Department of Biochemistry, Hazara University, Mansehra, Pakistan
| | - Irfan Ullah
- Department of Biological Sciences, Shaheed Benazir Bhutto University, Upper Dir, Pakistan
| | - Khurram Liaqat
- Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan
| | - Shoaib Nawaz
- Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan
| | - Wasim Ahmad
- Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan
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7
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Albizua I, Chopra P, Sherman SL, Gambello MJ, Warren ST. Analysis of the genomic expression profile in trisomy 18: insight into possible genes involved in the associated phenotypes. Hum Mol Genet 2020; 29:238-247. [PMID: 31813999 DOI: 10.1093/hmg/ddz279] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 01/12/2023] Open
Abstract
Trisomy 18, sometimes called Edwards syndrome, occurs in about 1 in 6000 live births and causes multiple birth defects in affected infants. The extra copy of chromosome 18 causes the altered expression of many genes and leads to severe skeletal, cardiovascular and neurological systems malformations as well as other medical problems. Due to the low rate of survival and the massive genetic imbalance, little research has been aimed at understanding the molecular consequences of trisomy 18 or considering potential therapeutic approaches. Our research is the first study to characterize whole-genome expression in fibroblast cells obtained from two patients with trisomy 18 and two matched controls, with follow-up expression confirmation studies on six independent controls. We show a detailed analysis of the most highly dysregulated genes on chromosome 18 and those genome-wide. The identified effector genes and the dysregulated downstream pathways provide hints of possible genotype-phenotype relationships to some of the most common symptoms observed in trisomy 18. We also provide a possible explanation for the sex-specific differences in survival, a unique characteristic of trisomy 18. Our analysis of genome-wide expression data moves us closer to understanding the molecular consequences of the second most common human autosomal trisomy of infants who survive to term. These insights might also translate to the understanding of the etiology of associated birth defects and medical conditions among those with trisomy 18.
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Affiliation(s)
- Igor Albizua
- Department of Human Genetics, Emory University School of Medicine, Atlanta, 30322, USA
| | - Pankaj Chopra
- Department of Human Genetics, Emory University School of Medicine, Atlanta, 30322, USA
| | - Stephanie L Sherman
- Department of Human Genetics, Emory University School of Medicine, Atlanta, 30322, USA
| | - Michael J Gambello
- Department of Human Genetics, Emory University School of Medicine, Atlanta, 30322, USA
| | - Stephen T Warren
- Department of Human Genetics, Emory University School of Medicine, Atlanta, 30322, USA
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8
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El-Ruby M, El-Din Fayez A, El-Dessouky SH, Aglan MS, Mazen I, Ismail N, Afifi HH, Eid MM, Mostafa MI, Mehrez MI, Khalil Y, Zaki MS, Gaber KR, Abdel-Hamid MS, Abdel-Salam GMH. Identification of a novel homozygous ALX4 mutation in two unrelated patients with frontonasal dysplasia type-2. Am J Med Genet A 2019; 176:1190-1194. [PMID: 29681084 DOI: 10.1002/ajmg.a.38655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/17/2017] [Accepted: 02/07/2018] [Indexed: 11/06/2022]
Abstract
We report two unrelated boys with frontonasal dysplasias type-2 (FND-2) who shared an identical novel homozygous ALX4 mutation c.291delG (p.Q98Sfs*83). Both patients presented with a large skull defect but one had bilateral parietal meningocele-like cysts that lie along with the bony defect and increased in size with age. Scalp alopecia, hypertelorism, and clefted alae nasi were also detected in both of them. Furthermore, impalpable gonads were noted, being unilateral in one and bilateral in the other. Neuroimaging showed small dysplastic occipital lobes with dysgyria and midline subarachnoid cyst. Additional dysplastic corpus callosum and small cerebellar vermis were observed in one patient. Parietal foramina were noted in the parents of one patient. Our findings highlight the dosage effect of ALX4 and underscore the challenges of prenatal genetic counseling. Further, the indirect role of ALX4 in the development of the occipital lobe and posterior fossa is discussed.
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Affiliation(s)
- Mona El-Ruby
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Alaa El-Din Fayez
- Medical Molecular Genetics and Enzymology Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Sara H El-Dessouky
- Prenatal Diagnosis and Fetal Medicine Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Mona S Aglan
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Inas Mazen
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Nora Ismail
- Medical Molecular Genetics and Enzymology Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Hanan H Afifi
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Maha M Eid
- Human Cytogenetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Mostafa I Mostafa
- Orodental Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Mennat I Mehrez
- Orodental Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Yasmin Khalil
- Orodental Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Khaled R Gaber
- Prenatal Diagnosis and Fetal Medicine Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Mohamed S Abdel-Hamid
- Medical Molecular Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Ghada M H Abdel-Salam
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
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9
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Ullah A, Umair M, E-Kalsoom U, Shahzad S, Basit S, Ahmad W. Exome sequencing revealed a novel nonsense variant in ALX3 gene underlying frontorhiny. J Hum Genet 2017; 63:97-100. [PMID: 29215096 DOI: 10.1038/s10038-017-0358-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/13/2017] [Accepted: 08/17/2017] [Indexed: 11/09/2022]
Abstract
Frontorhiny is one of the two forms of mid-facial malformations characterized by ocular hypertelorism, wide and short nasal ridge, bifid nasal tip, broad columella, widely separated nares, long and wide philtrum and V-shaped hairline. Sometimes these phenotypes are associated with ptosis and midline dermoid cysts. Frontorhiny inherits in an autosomal recessive pattern. Sequence variants in the Aristaless-like homeobox 3 (ALX3) gene underlying frontorhiny have been reported previously. Here, in the present study, we have investigated four patients in a consanguineous family of Pakistani origin segregating frontorhiny in autosomal recessive manner. Genome scan using 250k Nsp1 array followed by exome and Sanger sequence analysis revealed a novel homozygous nonsense variant (c.604C>T, p.Gln202*) in the ALX3 gene resulting in frontorhiny in the family. This is the first mutation in the ALX3 gene, underlying frontorhiny, in Pakistani population.
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Affiliation(s)
- Asmat Ullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Islamabad, Pakistan
| | - Muhammad Umair
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Islamabad, Pakistan
| | - Umm E-Kalsoom
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Islamabad, Pakistan
| | - Shaheen Shahzad
- Department of Biotechnology, International Islamic University, Islamabad, Pakistan
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University Al Madinah, Al Munawarah, Saudi Arabia
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
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10
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Mllt10 knockout mouse model reveals critical role of Af10-dependent H3K79 methylation in midfacial development. Sci Rep 2017; 7:11922. [PMID: 28931923 PMCID: PMC5607342 DOI: 10.1038/s41598-017-11745-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/30/2017] [Indexed: 01/04/2023] Open
Abstract
Epigenetic regulation is required to ensure the precise spatial and temporal pattern of gene expression that is necessary for embryonic development. Although the roles of some epigenetic modifications in embryonic development have been investigated in depth, the role of methylation at lysine 79 (H3K79me) is poorly understood. Dot1L, a unique methyltransferase for H3K79, forms complexes with distinct sets of co-factors. To further understand the role of H3K79me in embryogenesis, we generated a mouse knockout of Mllt10, the gene encoding Af10, one Dot1L complex co-factor. We find homozygous Mllt10 knockout mutants (Mllt10-KO) exhibit midline facial cleft. The midfacial defects of Mllt10-KO embryos correspond to hyperterolism and are associated with reduced proliferation of mesenchyme in developing nasal processes and adjacent tissue. We demonstrate that H3K79me level is significantly decreased in nasal processes of Mllt10-KO embryos. Importantly, we find that expression of AP2α, a gene critical for midfacial development, is directly regulated by Af10-dependent H3K79me, and expression AP2α is reduced specifically in nasal processes of Mllt10-KO embryos. Suppression of H3K79me completely mimicked the Mllt10-KO phenotype. Together these data are the first to demonstrate that Af10-dependent H3K79me is essential for development of nasal processes and adjacent tissues, and consequent midfacial formation.
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Farlie PG, Baker NL, Yap P, Tan TY. Frontonasal Dysplasia: Towards an Understanding of Molecular and Developmental Aetiology. Mol Syndromol 2016; 7:312-321. [PMID: 27920634 DOI: 10.1159/000450533] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 01/09/2023] Open
Abstract
The complex anatomy of the skull and face arises from the requirement to support multiple sensory and structural functions. During embryonic development, the diverse component elements of the neuro- and viscerocranium must be generated independently and subsequently united in a manner that sustains and promotes the growth of the brain and sensory organs, while achieving a level of structural integrity necessary for the individual to become a free-living organism. While each of these individual craniofacial components is essential, the cranial and facial midline lies at a structural nexus that unites these disparately derived elements, fusing them into a whole. Defects of the craniofacial midline can have a profound impact on both form and function, manifesting in a diverse array of phenotypes and clinical entities that can be broadly defined as frontonasal dysplasias (FNDs). Recent advances in the identification of the genetic basis of FNDs along with the analysis of developmental mechanisms impacted by these mutations have dramatically altered our understanding of this complex group of conditions.
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Affiliation(s)
- Peter G Farlie
- Murdoch Childrens Research Institute, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
| | - Naomi L Baker
- Murdoch Childrens Research Institute, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
| | - Patrick Yap
- Victorian Clinical Genetics Service, Royal Children's Hospital, University of Melbourne, Parkville, Vic., Australia; Genetic Health Service New Zealand (Northern Hub), Auckland City Hospital, Auckland, New Zealand
| | - Tiong Y Tan
- Victorian Clinical Genetics Service, Royal Children's Hospital, University of Melbourne, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
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12
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Ullah A, Kalsoom UE, Umair M, John P, Ansar M, Basit S, Ahmad W. Exome sequencing revealed a novel splice site variant in the ALX1 gene underlying frontonasal dysplasia. Clin Genet 2016; 91:494-498. [PMID: 27324866 DOI: 10.1111/cge.12822] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/11/2016] [Accepted: 06/13/2016] [Indexed: 12/19/2022]
Abstract
Frontonasal dysplasia (FND) is a heterogeneous group of disorders characterized by hypertelorism, telecanthus, broad nasal root, wide prominent nasal bridge, short and wide nasal ridge, broad columella and smooth philtrum. To date one X-linked and three autosomal recessive forms of FND have been reported in different ethnic groups. We sought to identify the gene responsible for FND in a consanguineous Pakistani family segregating the disorder in autosomal recessive pattern. Genome-wide homozygosity mapping using 250KNsp array revealed five homozygous regions in the selected affected individuals. Exome sequencing found a novel splice acceptor site variant (c.661-1G>C: NM_006982.2) in ALX1. Sanger sequencing confirmed the correct segregation of the pathogenic variant in the whole family. Our study concludes that the splice site variant identified in the ALX1 gene causes mild form of FND.
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Affiliation(s)
- A Ullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - U-E Kalsoom
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - M Umair
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - P John
- Department of Healthcare Biotechnology, Atta-ur-Rehman School of Applied Biosciences (ASAB), National University of Science & Technology (NUST), Islamabad, Pakistan
| | - M Ansar
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - S Basit
- Center for Genetics and Inherited Diseases, Taibah University, Al Madinah Al Munawarah, Saudi Arabia
| | - W Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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13
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Hufnagel RB, Zimmerman SL, Krueger LA, Bender PL, Ahmed ZM, Saal HM. A new frontonasal dysplasia syndrome associated with deletion of the SIX2 gene. Am J Med Genet A 2015; 170A:487-491. [PMID: 26581443 DOI: 10.1002/ajmg.a.37441] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 09/17/2015] [Indexed: 11/06/2022]
Abstract
The frontonasal dysplasias are a group of craniofacial phenotypes characterized by hypertelorism, nasal clefting, frontal bossing, and abnormal hairline. These conditions are caused by recessive mutations in members of the aristaless gene family, resulting in abnormal cranial neural crest migration and differentiation. We report a family with a dominantly inherited craniofacial phenotype comprised of frontal bossing with high hairline, ptosis, hypertelorism, broad nasal tip, large anterior fontanelle, cranial base anomalies, and sagittal synostosis. Chromosomal microarray identified a heterozygous 108.3 kilobase deletion of chromosome 2p21 segregating with phenotype and limited to the sine oculis homeobox gene SIX2 and surrounding noncoding DNA. Similar to the human SIX2 deletion phenotype, one mouse model of frontonasal dysplasia, brachyrrhine, exhibits dominant inheritance and impaired cranial base chondrogenesis associated with reduced Six2 expression. We report the first human autosomal dominant frontonasal dysplasia syndrome associated with SIX2 deletion and with phenotypic similarities to murine models of Six2 Loss-of-function.
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Affiliation(s)
- Robert B Hufnagel
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics. University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Sarah L Zimmerman
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics. University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Laura A Krueger
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics. University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Patricia L Bender
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics. University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Zubair M Ahmed
- Department of Otorhinolaryngology, University of Maryland, Baltimore, Maryland
| | - Howard M Saal
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics. University of Cincinnati College of Medicine, Cincinnati, Ohio
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14
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A 20 bp Duplication in Exon 2 of the Aristaless-Like Homeobox 4 Gene (ALX4) Is the Candidate Causative Mutation for Tibial Hemimelia Syndrome in Galloway Cattle. PLoS One 2015; 10:e0129208. [PMID: 26076463 PMCID: PMC4468193 DOI: 10.1371/journal.pone.0129208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 05/06/2015] [Indexed: 11/20/2022] Open
Abstract
Aristaless-like homeobox 4 (ALX4) gene is an important transcription regulator in skull and limb development. In humans and mice ALX4 mutations or loss of function result in a number of skeletal and organ malformations, including polydactyly, tibial hemimelia, omphalocele, biparietal foramina, impaired mammary epithelial morphogenesis, alopecia, coronal craniosynostosis, hypertelorism, depressed nasal bridge and ridge, bifid nasal tip, hypogonadism, and body agenesis. Here we show that a complex skeletal malformation of the hind limb in Galloway cattle together with other developmental anomalies is a recessive autosomal disorder most likely caused by a duplication of 20 bp in exon 2 of the bovine ALX4 gene. A second duplication of 34 bp in exon 4 of the same gene has no known effect, although both duplications result in a frameshift and premature stop codon leading to a truncated protein. Genotyping of 1,688 Black/Red/Belted/Riggit Galloway (GA) and 289 White Galloway (WGA) cattle showed that the duplication in exon 2 has allele frequencies of 1% in GA and 6% in WGA and the duplication in exon 4 has frequencies of 23% in GA and 38% in WGA. Both duplications were not detected in 876 randomly selected German Holstein Friesian and 86 cattle of 21 other breeds. Hence, we have identified a candidate causative mutation for tibial hemimelia syndrome in Galloway cattle and selection against this mutation can be used to eliminate the mutant allele from the breed.
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15
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Meloni V, Moysés-Oliveira M, Melo M, Caneloi T, Dantas A, Soares M, Fock R, Rodrigues de Nicola P, Dias-da-Silva M, Melaragno M. Novel homozygousALX4mutation causing frontonasal dysplasia-2 in a patient with meningoencephalocele. Clin Genet 2015; 88:593-6. [DOI: 10.1111/cge.12595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/06/2015] [Accepted: 04/07/2015] [Indexed: 11/28/2022]
Affiliation(s)
- V.A. Meloni
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - M. Moysés-Oliveira
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - M.C.C. Melo
- Department of Medicine, Division of Endocrinology; Universidade Federal de São Paulo; São Paulo Brazil
| | - T.P. Caneloi
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - A.G. Dantas
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - M.F.F. Soares
- Department of Imaging Diagnosis; Universidade Federal de São Paulo; São Paulo Brazil
| | - R. Fock
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - P.D. Rodrigues de Nicola
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
| | - M.R. Dias-da-Silva
- Department of Medicine, Division of Endocrinology; Universidade Federal de São Paulo; São Paulo Brazil
| | - M.I. Melaragno
- Department of Morphology and Genetics, Genetics Division; Universidade Federal de São Paulo; São Paulo Brazil
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Mathijssen IM, Versnel SL. Craniofacial clefts. Plast Reconstr Surg 2015. [DOI: 10.1002/9781118655412.ch20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Altunoglu U, Satkın B, Uyguner ZO, Kayserili H. Mild nasal clefting may be predictive for ALX4 heterozygotes. Am J Med Genet A 2014; 164A:2054-8. [PMID: 24764194 DOI: 10.1002/ajmg.a.36578] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 03/20/2014] [Indexed: 11/10/2022]
Abstract
Heterozygous loss-of-function mutations in ALX4 are responsible for enlarged parietal foramina, whereas patients with biallelic ALX4 mutations display a phenotypic spectrum of clinical findings, from mild to severe alopecia, cranium bifidum, hypertelorism, microphthalmia, with alar clefting being the pivotal sign in all affecteds. We report on four affected individuals in a three-generation family, displaying a phenotypic spectrum ranging from mild nasal clefting and broad columella to subtle changes in nasal configuration in addition to parietal foramina, caused by a novel ALX4 mutation (c.646C>G, p.Arg216Gly). This is the second report of a family showing vertical transmission of a dominant ALX4 mutation with facial involvement in addition to parietal foramina, mimicking mild recessive ALX4 phenotype. We discuss possible pathological mechanisms that may have lead to phenotypic variation in the family and challenges in genetic counseling.
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Affiliation(s)
- Umut Altunoglu
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
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18
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Kariminejad A, Bozorgmehr B, Alizadeh H, Ghaderi-Sohi S, Toksoy G, Uyguner ZO, Kayserili H. Skull defects, alopecia, hypertelorism, and notched alae nasi caused by homozygousALX4gene mutation. Am J Med Genet A 2014; 164A:1322-7. [DOI: 10.1002/ajmg.a.36008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/03/2013] [Indexed: 01/22/2023]
Affiliation(s)
| | - Bita Bozorgmehr
- Kariminejad-Najmabadi Pathology & Genetics Center; Tehran Iran
| | - Houman Alizadeh
- Tehran University of Medical Sciences, Children's Medical Center Hospital; Tehran Iran
| | | | - Güven Toksoy
- Medical Genetics Department, Istanbul Medical Faculty; Istanbul University; Istanbul Turkey
| | - Zehra Oya Uyguner
- Medical Genetics Department, Istanbul Medical Faculty; Istanbul University; Istanbul Turkey
| | - Hülya Kayserili
- Medical Genetics Department, Istanbul Medical Faculty; Istanbul University; Istanbul Turkey
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Ferrarini A, Gaillard M, Guerry F, Ramelli G, Heidi F, Keddache CV, Wieland I, Beckmann JS, Jaquemont S, Martinet D. Potocki-Shaffer deletion encompassing ALX4 in a patient with frontonasal dysplasia phenotype. Am J Med Genet A 2013; 164A:346-52. [PMID: 24376213 DOI: 10.1002/ajmg.a.36140] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 06/21/2013] [Indexed: 12/14/2022]
Abstract
Frontonasal dysplasia (FND) is a genetically heterogeneous malformation spectrum with marked hypertelorism, broad nasal tip and bifid nose. Only a small number of genes have been associated with FND phenotypes until now, the first gene being EFNB1, related to craniofrontonasal syndrome (CFNS) with craniosynostosis in addition, and more recently the aristaless-like homeobox genes ALX3, ALX4, and ALX1, which have been related with distinct phenotypes named FND1, FND2, and FND3 respectively. We here report on a female patient presenting with severe FND features along with partial alopecia, hypogonadism and intellectual disability. While molecular investigations did not reveal mutations in any of the known genes, ALX4, ALX3, ALX1 and EFNB1, comparative genomic hybridization (array CGH) techniques showed a large heterozygous de novo deletion at 11p11.12p12, encompassing the ALX4 gene. Deletions in this region have been described in patients with Potocki-Shaffer syndrome (PSS), characterized by biparietal foramina, multiple exostoses, and intellectual disability. Although the patient reported herein manifests some overlapping features of FND and PPS, it is likely that the observed phenotype maybe due to a second unidentified mutation in the ALX4 gene. The phenotype will be discussed in view of the deleted region encompassing the ALX4 gene.
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20
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Kappen C. Modeling anterior development in mice: diet as modulator of risk for neural tube defects. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2013; 163C:333-56. [PMID: 24124024 PMCID: PMC4149464 DOI: 10.1002/ajmg.c.31380] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Head morphogenesis is a complex process that is controlled by multiple signaling centers. The most common defects of cranial development are craniofacial defects, such as cleft lip and cleft palate, and neural tube defects, such as anencephaly and encephalocoele in humans. More than 400 genes that contribute to proper neural tube closure have been identified in experimental animals, but only very few causative gene mutations have been identified in humans, supporting the notion that environmental influences are critical. The intrauterine environment is influenced by maternal nutrition, and hence, maternal diet can modulate the risk for cranial and neural tube defects. This article reviews recent progress toward a better understanding of nutrients during pregnancy, with particular focus on mouse models for defective neural tube closure. At least four major patterns of nutrient responses are apparent, suggesting that multiple pathways are involved in the response, and likely in the underlying pathogenesis of the defects. Folic acid has been the most widely studied nutrient, and the diverse responses of the mouse models to folic acid supplementation indicate that folic acid is not universally beneficial, but that the effect is dependent on genetic configuration. If this is the case for other nutrients as well, efforts to prevent neural tube defects with nutritional supplementation may need to become more specifically targeted than previously appreciated. Mouse models are indispensable for a better understanding of nutrient-gene interactions in normal pregnancies, as well as in those affected by metabolic diseases, such as diabetes and obesity.
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Matsumaru D, Haraguchi R, Moon AM, Satoh Y, Nakagata N, Yamamura KI, Takahashi N, Kitazawa S, Yamada G. Genetic analysis of the role of Alx4 in the coordination of lower body and external genitalia formation. Eur J Hum Genet 2013; 22:350-7. [PMID: 23942202 PMCID: PMC3925283 DOI: 10.1038/ejhg.2013.160] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 04/11/2013] [Accepted: 05/08/2013] [Indexed: 12/15/2022] Open
Abstract
Although several syndromes include abnormalities of both the ventral body wall and external genitalia, the developmental bases of this correlation are largely unknown. Naturally occurring mutations in Aristaless-like 4 (Alx4, Strong's luxoid: Alx4Lst) have ventral body wall and pelvic girdle abnormalities. We sought to determine whether the development of the genital tubercle (GT) and its derivatives, the external genitalia, is affected by this mutation. We thus performed genetic and tissue labeling analyses in mutant mice. Alx4Lst/Lst mutants displayed hypoplasia of the dorsal GT and reduced expression of Fibronectin. We analyzed cell migration during GT formation by tissue labeling experiments and discovered that the cells located in the proximal segment of the umbilical cord (infra-umbilical mesenchyme) migrate toward the dorsal part of the GT. The Alx4Lst/Lst mutants also displayed augmented expression of Hh signal-related genes. Hence, we analyzed a series of combinatorial mutants for Alx4, Sonic hedgehog (Shh) and GLI-Kruppel family member 3 (Gli3). These phenotype–genotype analyses suggested a genetic interaction between Alx4 and Hh signaling during GT formation. Moreover, Hh gain-of-function mutants phenocopied some of these phenotypes. These observations reveal novel information regarding the pathogenic mechanisms of syndromic lower ventral body malformations, which are largely unknown.
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Affiliation(s)
- Daisuke Matsumaru
- 1] Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan [2] Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Ryuma Haraguchi
- 1] Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan [2] Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan [3] Department of Molecular Pathology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Anne M Moon
- Weis Center for Research, Geisinger Clinic, Danville, PA, USA
| | - Yoshihiko Satoh
- 1] Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan [2] Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Naomi Nakagata
- Division of Reproductive Engineering, Center for Animal Resources and Development, Kumamoto University, Kumamoto, Japan
| | - Ken-ichi Yamamura
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, Japan
| | - Naoki Takahashi
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Sohei Kitazawa
- Department of Molecular Pathology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Gen Yamada
- 1] Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan [2] Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
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Bertola DR, Rodrigues MG, Quaio CRDC, Kim CA, Passos-Bueno MR. Vertical transmission of a frontonasal phenotype caused by a novel ALX4 mutation. Am J Med Genet A 2013; 161A:600-4. [PMID: 23401352 DOI: 10.1002/ajmg.a.35762] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 10/16/2012] [Indexed: 11/06/2022]
Abstract
Frontonasal dysplasias (FND) comprise a spectrum of disorders caused by abnormal median facial development. Its etiology is still poorly understood but recently frontonasal dysplasia phenotypes were linked to loss-of-function mutations in the ALX homeobox gene family, which comprises the ALX1, ALX3, and ALX4 genes. All ALX-related frontonasal phenotypes till date had been compatible with an autosomal recessive mode of inheritance. In contrast, heterozygous loss-of-function mutations in ALX4 had been only associated with isolated symmetrical parietal ossification defects at the intersection of the sagittal and lambdoid sutures, known as enlarged parietal foramina. We report a family with vertical transmission from mother to son of mild frontonasal dysplasia phenotype caused by a novel ALX4 gene mutation (c.1080-1089_delGACCCGGTGCinsCTAAGATCTCAACAGAGATGGCAACT, p.Asp326fsX21).This is the first report of a frontonasal phenotype related to a heterozygous mutation in ALX4. This mutation is predicted to cause the loss of the aristaless domain in the C-terminal region of the protein and preserves the homeodomain. We speculate that a different mechanism, a dominant-negative effect, is responsible for the distinct phenotype in this family.
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Ribeiro-Bicudo LA, Quiezi RG, Guion-Almeida ML, Legnaro C, Richieri-Costa A. Exclusion of mutations in TGIF, ALX3, and ALX4 genes in patients with the syndrome of frontonasal dysgenesis, callosal agenesis, basal encephalocele, and eye anomalies. Am J Med Genet A 2012; 158A:1233-5. [DOI: 10.1002/ajmg.a.35305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 02/01/2012] [Indexed: 11/08/2022]
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