1
|
Reis LM, Seese SE, Costakos D, Semina EV. Congenital anterior segment ocular disorders: Genotype-phenotype correlations and emerging novel mechanisms. Prog Retin Eye Res 2024; 102:101288. [PMID: 39097141 DOI: 10.1016/j.preteyeres.2024.101288] [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: 03/30/2023] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/05/2024]
Abstract
Development of the anterior segment of the eye requires reciprocal sequential interactions between the arising tissues, facilitated by numerous genetic factors. Disruption of any of these processes results in congenital anomalies in the affected tissue(s) leading to anterior segment disorders (ASD) including aniridia, Axenfeld-Rieger anomaly, congenital corneal opacities (Peters anomaly, cornea plana, congenital primary aphakia), and primary congenital glaucoma. Current understanding of the genetic factors involved in ASD remains incomplete, with approximately 50% overall receiving a genetic diagnosis. While some genes are strongly associated with a specific clinical diagnosis, the majority of known factors are linked with highly variable phenotypic presentations, with pathogenic variants in FOXC1, CYP1B1, and PITX2 associated with the broadest spectrum of ASD conditions. This review discusses typical clinical presentations including associated systemic features of various forms of ASD; the latest functional data and genotype-phenotype correlations related to 25 ASD factors including newly identified genes; promising novel candidates; and current and emerging treatments for these complex conditions. Recent developments of interest in the genetics of ASD include identification of phenotypic expansions for several factors, discovery of multiple modes of inheritance for some genes, and novel mechanisms including a growing number of non-coding variants and alleles affecting specific domains/residues and requiring further studies.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Sarah E Seese
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Deborah Costakos
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Elena V Semina
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA; Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| |
Collapse
|
2
|
Akbar W, Ullah A, Haider N, Suleman S, Khan FU, Shah AA, Sikandar MA, Basit S, Ahmad W. Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia. J Gene Med 2024; 26:e3601. [PMID: 37758467 DOI: 10.1002/jgm.3601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/14/2023] [Accepted: 09/13/2023] [Indexed: 10/03/2023] Open
Abstract
BACKGROUND Anophthalmia and microphthalmia are severe developmental ocular disorders that affect the size of the ocular globe and can be unilateral or bilateral. The disease is found in syndromic as well as non-syndromic forms. It is genetically caused by chromosomal aberrations, copy number variations and single gene mutations, along with non-genetic factors such as viral infections, deficiency of vitamin A and an exposure to alcohol or drugs during pregnancy. To date, more than 30 genes having different modes of inheritance patterns are identified as causing anophthalmia and microphthalmia. METHODS In the present study, a clinical and genetic analysis was performed of six patients with anophthalmia and microphthalmia and/or additional phenotypes of intellectual disability, developmental delay and cerebral palsy from a large consanguineous Pakistani family. Whole exome sequencing followed by data analysis for variants prioritization and validation through Sanger sequencing was performed to identify the disease causing variant(s). American College of Medical Genetics and Genomics (ACMG) guidelines were applied to classify clinical interpretation of the prioritized variants. RESULTS Clinical investigations revealed that the affected individuals are afflicted with anophthalmia. Three of the patients showed additional phenotype of intellectual disability, developmental delays and other neurological symptoms. Whole exome sequencing of the DNA samples of the affected members in the family identified a novel homozygous stop gain mutation (NM_012186: c.106G>T: p.Glu36*) in Forkhead Box E3 (FOXE3) gene shared by all affected individuals. Moreover, patients segregating additional phenotypes of spastic paraplegia, intellectual disability, hearing loss and microcephaly showed an additional homozygous sequence variant (NM_004722: c.953G>A: p.Arg318Gln) in AP4M1. Sanger sequencing validated the correct segregation of the identified variants in the affected family. ACMG guidelines predicted the variants to be pathogenic. CONCLUSIONS We have investigated first case of syndromic anophthalmia caused by variants in the FOXE3 and AP4M1. The present findings are helpful for understanding pathological role of the mutations of the genes in syndromic forms of anophthalmia. Furthermore, the study signifies searching for the identification of second variant in families with patients exhibiting variable phenotypes. In addition, the findings will help clinical geneticists, genetic counselors and the affected family with respect to prenatal testing, family planning and genetic counseling.
Collapse
Affiliation(s)
- Warda Akbar
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Asmat Ullah
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Nighat Haider
- Shaheed Zulfiqar Ali Bhutto Medical University, Department of Pediatrics, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Sufyan Suleman
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Fati Ullah Khan
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Abid Ali Shah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | | | - Sulman Basit
- College of Medicine, Taibah University, Medina, Saudi Arabia
- Center for Genetics and Inherited Diseases, Taibah University, Medina, Saudi Arabia
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| |
Collapse
|
3
|
Elbaz U, Ali A, Strungaru H, Mireskandari K. Phenotypic Spectrum of Peters Anomaly: Implications for Management. Cornea 2022; 41:192-200. [PMID: 34176915 DOI: 10.1097/ico.0000000000002768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/28/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to characterize the wide phenotypic spectrum of Peters anomaly and to suggest a management algorithm based on disease phenotype. METHODS The charts of all children diagnosed with Peters anomaly between January 2000 and December 2013 were reviewed retrospectively. Anterior segment color photographs, anterior segment optical coherence tomography, and ultrasound biomicroscopy images were used to phenotype disease severity and to guide management. Disease severity was categorized to Peters anomaly type I and II according to lens involvement. Peters anomaly type I and II were further categorized from mild to severe disease according to the size and location of corneal opacity. Associated systemic findings were also documented. RESULTS Eighty eyes of 54 patients with Peters anomaly were identified, of which 28 (51.9%) had unilateral disease. Peters anomaly type I was present in 40 patients (57 eyes, 71.2%) and Peters anomaly type II in 14 patients (23 eyes, 28.8%). Nine eyes (11.3%) had phenotypic features that required observation only, 24 eyes (30%) were amenable to pupillary dilation, 43 eyes (53.8%) with large, dense central opacity required penetrating keratoplasty, and 4 eyes (5.0%) had no intervention because of very poor prognostic features. Associated systemic abnormalities occurred frequently in Peters anomaly (n = 20, 37.0%), with congenital heart defect being the most common morbidity (n = 10, 18.5%). CONCLUSIONS Peters anomaly presents with a variable phenotype ranging from minimal peripheral corneal opacity to extensive iris and lens adhesions with dense central corneal opacity detrimental to vision. Management can be standardized and guided by an algorithm based on phenotypic severity. Systemic abnormalities should be ruled out, regardless of the severity of Peters anomaly.
Collapse
Affiliation(s)
- Uri Elbaz
- Department of Ophthalmology, Rabin Medical Center, Schneider Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Asim Ali
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Hermina Strungaru
- Peterborough Health Regional Center, Peterborough, ON, Canada; and
- Department of Ophthalmology and Vision Sciences, University of Alberta, Edmonton, AB, Canada
| | - Kamiar Mireskandari
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
4
|
Ong APC, Zhang J, Vincent AL, McGhee CNJ. Megalocornea, anterior megalophthalmos, keratoglobus and associated anterior segment disorders: A review. Clin Exp Ophthalmol 2021; 49:477-497. [PMID: 34114333 DOI: 10.1111/ceo.13958] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 01/21/2023]
Abstract
Megalocornea and anterior megalophthalmos (megalocornea spectrum) disorders are typically defined by corneal diameter > 12.5 mm in the absence of elevated intraocular pressure. Clinical features overlap with keratoglobus but are distinct from buphthalmos and severe (globus) keratoconus. Megalocornea spectrum disorders and keratoglobus are primarily congenital disorders, often with syndromic associations; both can present with large and thin corneas, creating difficulty in diagnosis, however, only keratoglobus is typically progressive. Molecular genetics provide significant insight into underlying aetiologies. Nonetheless, careful clinical assessment remains intrinsic to diagnosis. Surgical management can be challenging due to the enlarged ciliary ring and weakened zonules in megalocornea spectrum disorders and the extreme corneal thinning of keratoglobus. In this review, the established literature on measurement of corneal diameter, diagnosis of megalocornea, anterior megalophthalmos and keratoglobus, differentiation from severe keratoconus, recent molecular genetics research and key surgical modalities in the management of these rare disorders are outlined and discussed.
Collapse
Affiliation(s)
- Aaron P C Ong
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Department of Ophthalmology, Southern District Health Board, Dunedin, New Zealand
| | - Jie Zhang
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Andrea L Vincent
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Charles N J McGhee
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| |
Collapse
|
5
|
Reis LM, Sorokina EA, Dudakova L, Moravikova J, Skalicka P, Malinka F, Seese SE, Thompson S, Bardakjian T, Capasso J, Allen W, Glaser T, Levin AV, Schneider A, Khan A, Liskova P, Semina EV. Comprehensive phenotypic and functional analysis of dominant and recessive FOXE3 alleles in ocular developmental disorders. Hum Mol Genet 2021; 30:1591-1606. [PMID: 34046667 PMCID: PMC8369840 DOI: 10.1093/hmg/ddab142] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/16/2022] Open
Abstract
The forkhead transcription factor FOXE3 is critical for vertebrate eye development. Recessive and dominant variants cause human ocular disease but the full range of phenotypes and mechanisms of action for the two classes of variants are unknown. We identified FOXE3 variants in individuals with congenital eye malformations and carried out in vitro functional analysis on selected alleles. Sixteen new recessive and dominant families, including six novel variants, were identified. Analysis of new and previously reported genetic and clinical data demonstrated a broad phenotypic range with an overlap between recessive and dominant disease. Most families with recessive alleles, composed of truncating and forkhead-domain missense variants, had severe corneal opacity (90%; sclerocornea in 47%), aphakia (83%) and microphthalmia (80%), but some had milder features including isolated cataract. The phenotype was most variable for recessive missense variants, suggesting that the functional consequences may be highly dependent on the type of amino acid substitution and its position. When assessed, aniridia or iris hypoplasia were noted in 89% and optic nerve anomalies in 60% of recessive cases, indicating that these defects are also common and may be underrecognized. In dominant pedigrees, caused by extension variants, normal eye size (96%), cataracts (99%) and variable anterior segment anomalies were seen in most, but some individuals had microphthalmia, aphakia or sclerocornea, more typical of recessive disease. Functional studies identified variable effects on the protein stability, DNA binding, nuclear localization and transcriptional activity for recessive FOXE3 variants, whereas dominant alleles showed severe impairment in all areas and dominant-negative characteristics.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Elena A Sorokina
- Department of Pediatrics and Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Lubica Dudakova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jana Moravikova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Frantisek Malinka
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.,Department of Computer Science, Czech Technical University in Prague, Prague, Czech Republic
| | - Sarah E Seese
- Department of Pediatrics and Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Samuel Thompson
- Department of Pediatrics and Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Tanya Bardakjian
- Department of Pediatrics, Albert Einstein Medical Center, Philadelphia, PA 19141, USA
| | - Jenina Capasso
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Pediatric Genetics, Golisano Children's Hospital, University of Rochester, Rochester, NY 14534 USA
| | - William Allen
- Fullerton Genetics Center, Mission Hospitals, HCA, Asheville, NC, 28803 USA
| | - Tom Glaser
- Cell Biology and Human Anatomy Department, UC-Davis School of Medicine, Davis, CA 95616, USA
| | - Alex V Levin
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Pediatric Genetics, Golisano Children's Hospital, University of Rochester, Rochester, NY 14534 USA
| | - Adele Schneider
- Department of Pediatrics, Albert Einstein Medical Center, Philadelphia, PA 19141, USA
| | - Ayesha Khan
- Pediatric Ophthalmology & Strabismus Unit, Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan.,Consultant Pediatric Ophthalmologist, Al Jalila Children's Specialty Hospital, United Arab Emirates
| | - Petra Liskova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA.,Departments of Ophthalmology and Cell Biology, Neurobiology and Anatomy at the Medical College of Wisconsin, Milwaukee, WI 53226, USA
| |
Collapse
|
6
|
Darbari E, Zare-Abdollahi D, Alavi A, Rezaei Kanavi M, Feizi S, Hosseini SB, Baradaran-Rafii A, Ahmadieh H, Issazadeh-Navikas S, Elahi E. A mutation in DOP1B identified as a probable cause for autosomal recessive Peters anomaly in a consanguineous family. Mol Vis 2020; 26:757-765. [PMID: 33273802 PMCID: PMC7700884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 11/23/2020] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Peters anomaly (PA) is a heterogeneous developmental disorder characterized by central corneal opacity and iridocorneal or corneolenticular adhesions. Although many causative genes have been identified, most screened patients do not have mutations in the known genes. We aimed to identify the genetic cause of Peters anomaly in a pedigree with three affected individuals. METHODS Slit-lamp biomicroscopy and ultrasound biomicroscopy were performed for definitive diagnosis. Exome sequencing was conducted on the DNA of all three patients. After identification of a candidate causative gene, expression of the gene was assessed with real-time PCR in various ocular tissues of three human embryos and three adults. RESULTS The patients were affected with isolated PA. The parents of the patients were related to one another. Inheritance of PA was autosomal recessive. After appropriate filtering of the exome data, a homozygous variation in DOP1B remained as the only candidate genetic cause of PA in the pedigree. The variant segregated with disease status in the pedigree and was absent among 800 control Iranians. The variant has been reported in various databases at frequencies of 0.006 or less only in the heterozygous state in some cohorts of African origin. The p.Val1660 amino acid affected by the mutation is completely conserved in mammals and birds during evolution. Expression of DOP1B was shown in all adult and embryonic lens, iris, cornea, sclera, and retina tissues that were tested. CONCLUSIONS DOP1B that encodes DOP1 leucine zipper like protein B was identified as the putative PA-causing gene in pedigree PA-101. As DOP1B is positioned within the Down syndrome chromosomal region on chromosome 21, until now this gene has mostly been studied with respect to brain functions. However, members of the Dopey gene family have been shown to have roles in development in other organisms. Evidence of the expression of DOP1B in various PA-relevant eye tissues, which, to the best of our knowledge, is shown here for the first time, is to be noted. However, this finding does not necessarily implicate a specific role for DOP1B in eye development as the gene is expressed in many tissues. Ultimately, definitive assessment of the contribution of DOP1B to PA pathology awaits identification of mutations in the gene in unrelated patients with PA and functional studies.
Collapse
Affiliation(s)
- Ensieh Darbari
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Davood Zare-Abdollahi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Afagh Alavi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Mozhgan Rezaei Kanavi
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sepehr Feizi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Alireza Baradaran-Rafii
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shohreh Issazadeh-Navikas
- Neuroinflammation Unit, Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, Copenhagen Biocentre, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| |
Collapse
|
7
|
Dhamija S, Yang CM, Seiler J, Myacheva K, Caudron-Herger M, Wieland A, Abdelkarim M, Sharma Y, Riester M, Groß M, Maurer J, Diederichs S. A pan-cancer analysis reveals nonstop extension mutations causing SMAD4 tumour suppressor degradation. Nat Cell Biol 2020; 22:999-1010. [DOI: 10.1038/s41556-020-0551-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/25/2020] [Indexed: 12/26/2022]
|
8
|
Genetics of anophthalmia and microphthalmia. Part 1: Non-syndromic anophthalmia/microphthalmia. Hum Genet 2019; 138:799-830. [PMID: 30762128 DOI: 10.1007/s00439-019-01977-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/30/2019] [Indexed: 12/22/2022]
Abstract
Eye formation is the result of coordinated induction and differentiation processes during embryogenesis. Disruption of any one of these events has the potential to cause ocular growth and structural defects, such as anophthalmia and microphthalmia (A/M). A/M can be isolated or occur with systemic anomalies, when they may form part of a recognizable syndrome. Their etiology includes genetic and environmental factors; several hundred genes involved in ocular development have been identified in humans or animal models. In humans, around 30 genes have been repeatedly implicated in A/M families, although many other genes have been described in single cases or families, and some genetic syndromes include eye anomalies occasionally as part of a wider phenotype. As a result of this broad genetic heterogeneity, with one or two notable exceptions, each gene explains only a small percentage of cases. Given the overlapping phenotypes, these genes can be most efficiently tested on panels or by whole exome/genome sequencing for the purposes of molecular diagnosis. However, despite whole exome/genome testing more than half of patients currently remain without a molecular diagnosis. The proportion of undiagnosed cases is even higher in those individuals with unilateral or milder phenotypes. Furthermore, even when a strong gene candidate is available for a patient, issues of incomplete penetrance and germinal mosaicism make diagnosis and genetic counseling challenging. In this review, we present the main genes implicated in non-syndromic human A/M phenotypes and, for practical purposes, classify them according to the most frequent or predominant phenotype each is associated with. Our intention is that this will allow clinicians to rank and prioritize their molecular analyses and interpretations according to the phenotypes of their patients.
Collapse
|
9
|
Reis LM, Semina EV. Genetic landscape of isolated pediatric cataracts: extreme heterogeneity and variable inheritance patterns within genes. Hum Genet 2018; 138:847-863. [PMID: 30187164 DOI: 10.1007/s00439-018-1932-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
Pediatric cataract represents an important cause of pediatric visual impairment. While both genetic and environmental causes for pediatric cataract are known, a large proportion remains idiopathic. The purpose of this review is to discuss genes involved in isolated pediatric cataract, with a focus on variable inheritance patterns within genes. Mutations in over 52 genes are known to cause isolated pediatric cataract, with a major contribution from genes encoding for crystallins, transcription factors, membrane proteins, and cytoskeletal proteins. Interestingly, both dominant and recessive inheritance patterns have been reported for mutations in 13 different cataract genes. For some genes, dominant and recessive alleles represent distinct types of mutations, but for many, especially missense variants, there are no clear patterns to distinguish between dominant and recessive alleles. Further research into the functional effects of these mutations, as well as additional data on the frequency of the identified variants, is needed to clarify variant pathogenicity. Exome sequencing continues to be successful in identifying novel genes associated with congenital cataract but is hindered by the extreme genetic heterogeneity of this condition. The large number of idiopathic cases suggests that more genes and potentially novel mechanisms of gene disruption remain to be identified.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA. .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| |
Collapse
|
10
|
CUGC for congenital primary aphakia. Eur J Hum Genet 2018; 26:1234-1237. [PMID: 29769628 DOI: 10.1038/s41431-018-0171-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 02/14/2018] [Accepted: 04/26/2018] [Indexed: 11/08/2022] Open
|
11
|
A zebrafish model of foxe3 deficiency demonstrates lens and eye defects with dysregulation of key genes involved in cataract formation in humans. Hum Genet 2018; 137:315-328. [PMID: 29713869 DOI: 10.1007/s00439-018-1884-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/16/2018] [Indexed: 12/14/2022]
Abstract
The Forkhead box E3 (FOXE3) gene encodes a transcription factor with a forkhead/winged helix domain that is critical for development of the lens and anterior segment of the eye. Monoallelic and biallelic deleterious sequence variants in FOXE3 cause aphakia, cataracts, sclerocornea and microphthalmia in humans. We used clustered regularly interspaced short palindromic repeats/Cas9 injections to target the foxe3 transcript in zebrafish in order to create an experimental model of loss of function for this gene. Larvae that were homozygous for an indel variant, c.296_300delTGCAG, predicting p.(Val99Alafs*2), demonstrated severe eye defects, including small or absent lenses and microphthalmia. The lenses of the homozygous foxe3 indel mutants showed more intense staining with zl-1 antibody compared to control lenses, consistent with increased lens fiber cell differentiation. Whole genome transcriptome analysis (RNA-Seq) on RNA isolated from wildtype larvae and larvae with eye defects that were putative homozygotes for the foxe3 indel variant found significant dysregulation of genes expressed in the lens and eye whose orthologues are associated with cataracts in human patients, including cryba2a, cryba1l1, mipa and hsf4. Comparative analysis of this RNA-seq data with iSyTE data identified several lens-enriched genes to be down-regulated in foxe3 indel mutants. We also noted upregulation of lgsn and crygmxl2 and downregulation of fmodb and cx43.4, genes that are expressed in the zebrafish lens, but that are not yet associated with an eye phenotype in humans. These findings demonstrate that this new zebrafish foxe3 mutant model is highly relevant to the study of the gene regulatory networks conserved in vertebrate lens and eye development.
Collapse
|
12
|
Anand D, Agrawal SA, Slavotinek A, Lachke SA. Mutation update of transcription factor genes FOXE3, HSF4, MAF, and PITX3 causing cataracts and other developmental ocular defects. Hum Mutat 2018; 39:471-494. [PMID: 29314435 PMCID: PMC5839989 DOI: 10.1002/humu.23395] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/19/2017] [Accepted: 12/22/2017] [Indexed: 02/06/2023]
Abstract
Mutations in the transcription factor genes FOXE3, HSF4, MAF, and PITX3 cause congenital lens defects including cataracts that may be accompanied by defects in other components of the eye or in nonocular tissues. We comprehensively describe here all the variants in FOXE3, HSF4, MAF, and PITX3 genes linked to human developmental defects. A total of 52 variants for FOXE3, 18 variants for HSF4, 20 variants for MAF, and 19 variants for PITX3 identified so far in isolated cases or within families are documented. This effort reveals FOXE3, HSF4, MAF, and PITX3 to have 33, 16, 18, and 7 unique causal mutations, respectively. Loss-of-function mutant animals for these genes have served to model the pathobiology of the associated human defects, and we discuss the currently known molecular function of these genes, particularly with emphasis on their role in ocular development. Finally, we make the detailed FOXE3, HSF4, MAF, and PITX3 variant information available in the Leiden Online Variation Database (LOVD) platform at https://www.LOVD.nl/FOXE3, https://www.LOVD.nl/HSF4, https://www.LOVD.nl/MAF, and https://www.LOVD.nl/PITX3. Thus, this article informs on key variants in transcription factor genes linked to cataract, aphakia, corneal opacity, glaucoma, microcornea, microphthalmia, anterior segment mesenchymal dysgenesis, and Ayme-Gripp syndrome, and facilitates their access through Web-based databases.
Collapse
Affiliation(s)
- Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Smriti A. Agrawal
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Anne Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, UCSF Benioff Children’s Hospital, San Francisco, CA 19716 USA
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711 USA
| |
Collapse
|
13
|
Plaisancié J, Ragge N, Dollfus H, Kaplan J, Lehalle D, Francannet C, Morin G, Colineaux H, Calvas P, Chassaing N. FOXE3
mutations: genotype-phenotype correlations. Clin Genet 2018; 93:837-845. [DOI: 10.1111/cge.13177] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/25/2023]
Affiliation(s)
- J. Plaisancié
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse; Toulouse France
- INSERM U1056; Université Toulouse III; Toulouse France
| | - N.K. Ragge
- Faculty of Health and Life Sciences; Oxford Brookes University; Oxford UK
- West Midlands Regional Genetics Service; Birmingham Women and Children’s NHS Foundation Trust; Birmingham UK
| | - H. Dollfus
- Centre de Référence pour les affections rares en génétique ophtalmologique; CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg; Strasbourg France
| | - J. Kaplan
- INSERM U1163; Génétique Ophtalmologique; Paris France
| | - D. Lehalle
- Centre de Génétique et Centre de Référence "Anomalies du Développement et Syndromes Malformatifs; Hôpital d'Enfants; Dijon France
| | - C. Francannet
- Service de Génétique Médicale; CHU Estaing; Clermont-Ferrand France
| | - G. Morin
- Service de génétique; Hôpital nord d’Amiens; Amiens France
| | - H. Colineaux
- Department of Epidemiology, Health Economics and Public Health; Toulouse University Hospital; France
- LEASP UMR1027, INSERM; Université Toulouse III; Toulouse France
| | - P. Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse; Toulouse France
- INSERM U1056; Université Toulouse III; Toulouse France
| | - N. Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse; Toulouse France
- INSERM U1056; Université Toulouse III; Toulouse France
| |
Collapse
|
14
|
David D, Anand D, Araújo C, Gloss B, Fino J, Dinger M, Lindahl P, Pöyhönen M, Hannele L, Lavinha J. Identification of OAF and PVRL1 as candidate genes for an ocular anomaly characterized by Peters anomaly type 2 and ectopia lentis. Exp Eye Res 2018; 168:161-170. [PMID: 29305299 DOI: 10.1016/j.exer.2017.12.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 12/21/2017] [Accepted: 12/27/2017] [Indexed: 01/10/2023]
Abstract
Keratolenticular dysgenesis (KLD) and ectopia lentis are congenital eye defects. The aim of this study is the identification of molecular genetic alterations responsible for those ocular anomalies with neurologic impairment in an individual with a de novo balanced chromosome translocation t(11;18)(q23.3;q11.2)dn. Disruption of OAF, the human orthologue of the Drosophila oaf, by the 11q23.3 breakpoint results in reduced expression of this transcriptional regulator. Furthermore, four most likely nonfunctional chimeric transcripts comprising up to OAF exon 3, derived from the der(11) allele, have also been identified. This locus has been implicated by publicly available genome-wide association data in corneal disease and corneal topography. The expression of the poliovirus receptor-related 1(PVRL1) or nectin cell adhesion molecule 1 (NECTIN1), a paralogue of nectin cell adhesion molecule 3 (PVRL3) associated with congenital ocular defects, situated 500 kb upstream from 11q23.3 breakpoint, is increased. The 18q11.2 breakpoint is localized between cutaneous T-cell lymphoma-associated antigen 1(CTAGE1) and retinoblastoma binding protein 8 (RBBP8) genes. Genomic imbalance that could contribute to the observed phenotype was excluded. Analysis of gene expression datasets throughout normal murine ocular lens embryogenesis suggests that OAF expression is significantly enriched in the lens from early stages of development through adulthood, whereas PVRL1 is lens-enriched until E12.5 and then down-regulated. This contrasts with the observation that the proposita's lymphoblastoid cell lines exhibit low OAF and high PVRL1 expression as compared to control, which offers further support that the alterations described above are most likely responsible for the clinical phenotype. Finally, gene interaction topology data for PVRL1 also agree with our proposal that disruption of OAF by the translocation breakpoint and misregulation of PVRL1 due to a position effect contribute to the observed ocular and neurological phenotype.
Collapse
Affiliation(s)
- Dezső David
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal.
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Carlos Araújo
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal
| | - Brian Gloss
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW, Kensington, Australia
| | - Joana Fino
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal
| | - Marcel Dinger
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW, Kensington, Australia
| | - Päivi Lindahl
- Ophthalmology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Minna Pöyhönen
- Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Laivuori Hannele
- Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - João Lavinha
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal
| |
Collapse
|
15
|
Sun J, Hao Z, Luo H, He C, Mei L, Liu Y, Wang X, Niu Z, Chen H, Li JD, Feng Y. Functional analysis of a nonstop mutation in MITF gene identified in a patient with Waardenburg syndrome type 2. J Hum Genet 2017; 62:703-709. [PMID: 28356565 PMCID: PMC5489919 DOI: 10.1038/jhg.2017.30] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/30/2017] [Accepted: 02/07/2017] [Indexed: 11/09/2022]
Abstract
Waardenburg syndrome (WS) is an autosomal dominant inherited neurogenic disorder with the combination of various degrees of sensorineural deafness and pigmentary abnormalities affecting the skin, hair and eye. The four subtypes of WS were defined on the basis of the presence or absence of additional symptoms. Mutation of human microphthalmia-associated transcription factor (MITF) gene gives rise to WS2. Here, we identified a novel WS-associated mutation at the stop codon of MITF (p.X420Y) in a Chinese WS2 patient. This mutation resulted in an extension of extra 33 amino-acid residues in MITF. The mutant MITF appeared in both the nucleus and the cytoplasm, whereas the wild-type MITF was localized in the nucleus exclusively. The mutation led to a reduction in the transcriptional activities, whereas the DNA-binding activity was not altered. We show that the foremost mechanism was haploinsufficiency for the mild phenotypes of WS2 induced in X420Y MITF.
Collapse
Affiliation(s)
- Jie Sun
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Department of Otolaryngology, First Affiliated Hospital, Xinjiang Medical University, Xinjiang, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Ziqi Hao
- Department of Center Laboratory, Taiyuan Central Hospital, Shanxi, People's Republic of China
| | - Hunjin Luo
- State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
| | - Chufeng He
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Lingyun Mei
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Yalan Liu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Xueping Wang
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Zhijie Niu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China
| | - Hongsheng Chen
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China
| | - Jia-Da Li
- State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
| | - Yong Feng
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China.,Department of Center Laboratory, Taiyuan Central Hospital, Shanxi, People's Republic of China.,State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
| |
Collapse
|
16
|
Messina-Baas O, Cuevas-Covarrubias SA. Inherited Congenital Cataract: A Guide to Suspect the Genetic Etiology in the Cataract Genesis. Mol Syndromol 2017; 8:58-78. [PMID: 28611546 DOI: 10.1159/000455752] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2016] [Indexed: 01/23/2023] Open
Abstract
Cataracts are the principal cause of treatable blindness worldwide. Inherited congenital cataract (CC) shows all types of inheritance patterns in a syndromic and nonsyndromic form. There are more than 100 genes associated with cataract with a predominance of autosomal dominant inheritance. A cataract is defined as an opacity of the lens producing a variation of the refractive index of the lens. This variation derives from modifications in the lens structure resulting in light scattering, frequently a consequence of a significant concentration of high-molecular-weight protein aggregates. The aim of this review is to introduce a guide to identify the gene involved in inherited CC. Due to the manifold clinical and genetic heterogeneity, we discarded the cataract phenotype as a cardinal sign; a 4-group classification with the genes implicated in inherited CC is proposed. We consider that this classification will assist in identifying the probable gene involved in inherited CC.
Collapse
|
17
|
Doucette LP, Walter MA. Prostaglandins in the eye: Function, expression, and roles in glaucoma. Ophthalmic Genet 2016; 38:108-116. [PMID: 27070211 DOI: 10.3109/13816810.2016.1164193] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Prostaglandins are small pro-inflammatory molecules derived from arachidonic acid that play roles in a multitude of biological processes including, but not limited to, inflammation, pain modulation, allergies, and bone formation. Prostaglandin analogues are the front-line medications for the treatment of glaucoma, a condition resulting in blindness due to the death of retinal ganglion cells. These drugs act by lowering intraocular pressure (IOP), a major risk factor for glaucoma. The currently used prostaglandin analogues (latanoprost, bimatoprost, tafluprost, and travoprost) mimic PGF2 and target one of the prostaglandin receptors (FP), though research into harnessing the other receptors using compounds like Sulprostone (EP3 receptor), or Iloprost (IP receptor) are currently ongoing. In this review, we summarize the research into each of the prostaglandin molecules (PGD2, PGE2, PGF2, PGI2, TXA2) and their respective receptors (DP, EP1, 2, 3, 4, FP, IP). We examine the modes of action of each of these receptors, their expression, their role in aqueous humour production and outflow within the eye, as well as their roles as medications for the treatment of glaucoma.
Collapse
Affiliation(s)
- Lance P Doucette
- a Department of Medical Genetics, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada
| | - Michael A Walter
- a Department of Medical Genetics, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada
| |
Collapse
|
18
|
FOXE3 contributes to Peters anomaly through transcriptional regulation of an autophagy-associated protein termed DNAJB1. Nat Commun 2016; 7:10953. [PMID: 27218149 PMCID: PMC4820811 DOI: 10.1038/ncomms10953] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/04/2016] [Indexed: 02/04/2023] Open
Abstract
FOXE3 is a lens-specific transcription factor that has been associated with anterior segment ocular dysgenesis. To determine the transcriptional target(s) of FOXE3 that are indispensable for the anterior segment development, we examined the transcriptome and the proteome of cells expressing truncated FOXE3 responsible for Peters anomaly identified through linkage-coupled next-generation whole-exome sequencing. We found that DNAJB1, an autophagy-associated protein, was the only candidate exhibiting differential expression in both screens. We confirmed the candidacy of DNAJB1 through chromatin immunoprecipitation and luciferase assays while knockdown of DNAJB1 in human lens epithelial cells resulted in a mitotic arrest. Subsequently, we targeted dnajb1a in zebrafish through injection of a splice-blocking morpholino. The dnajb1a morphants exhibited underdeveloped cataractous lenses with persistent apoptotic nuclei. In conclusion, here we report DNAJB1 is a transcriptional target of FOXE3 in a novel pathway that is crucial for the development of the anterior segment of the eye.
Collapse
|
19
|
Islam L, Kelberman D, Williamson L, Lewis N, Glindzicz MB, Nischal KK, Sowden JC. Functional Analysis of FOXE3
Mutations Causing Dominant and Recessive Ocular Anterior Segment Disease. Hum Mutat 2015; 36:296-300. [DOI: 10.1002/humu.22741] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 12/05/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Lily Islam
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
| | - Daniel Kelberman
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
| | - Laura Williamson
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
| | - Nicola Lewis
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
| | | | - Ken K. Nischal
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
- Clinical and Academic Department of Ophthalmology; Great Ormond Street Hospital for Children NHS Foundation Trust; London UK
| | - Jane C. Sowden
- Developmental Biology and Cancer; Birth Defects Research Centre; UCL Institute of Child Health; London UK
| |
Collapse
|
20
|
Choi A, Lao R, Ling-Fung Tang P, Wan E, Mayer W, Bardakjian T, Shaw GM, Kwok PY, Schneider A, Slavotinek A. Novel mutations in PXDN cause microphthalmia and anterior segment dysgenesis. Eur J Hum Genet 2014; 23:337-41. [PMID: 24939590 DOI: 10.1038/ejhg.2014.119] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 12/25/2022] Open
Abstract
We used exome sequencing to study a non-consanguineous family with two children who had anterior segment dysgenesis, sclerocornea, microphthalmia, hypotonia and developmental delays. Sanger sequencing verified two Peroxidasin (PXDN) mutations in both sibs--a maternally inherited, nonsense mutation, c.1021C>T predicting p.(Arg341*), and a paternally inherited, 23-basepair deletion causing a frameshift and premature protein truncation, c.2375_2397del23, predicting p.(Leu792Hisfs*67). We re-examined exome data from 20 other patients with structural eye defects and identified two additional PXDN mutations in a sporadic male with bilateral microphthalmia, cataracts and anterior segment dysgenesis--a maternally inherited, frameshift mutation, c.1192delT, predicting p.(Tyr398Thrfs*40) and a paternally inherited, missense substitution that was predicted to be deleterious, c.947 A>C, predicting p.(Gln316Pro). Mutations in PXDN were previously reported in three families with congenital cataracts, microcornea, sclerocornea and developmental glaucoma. The gene is expressed in corneal epithelium and is secreted into the extracellular matrix. Defective peroxidasin has been shown to impair sulfilimine bond formation in collagen IV, a constituent of the basement membrane, implying that the eye defects result because of loss of basement membrane integrity in the developing eye. Our finding of a broader phenotype than previously appreciated for PXDN mutations is typical for exome-sequencing studies, which have proven to be highly effective for mutation detection in patients with atypical presentations. We conclude that PXDN sequencing should be considered in microphthalmia with anterior segment dysgenesis.
Collapse
Affiliation(s)
- Alex Choi
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, CA, USA
| | - Richard Lao
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Paul Ling-Fung Tang
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Eunice Wan
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Wasima Mayer
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, CA, USA
| | - Tanya Bardakjian
- Division of Medical Genetics, Einstein Medical Center, Philadelphia, PA, USA
| | - Gary M Shaw
- Division of Neonatology and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Pui-Yan Kwok
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Adele Schneider
- Division of Medical Genetics, Einstein Medical Center, Philadelphia, PA, USA
| | - Anne Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, CA, USA
| |
Collapse
|
21
|
Reis LM, Tyler RC, Semina EV. Identification of a novel C-terminal extension mutation in EPHA2 in a family affected with congenital cataract. Mol Vis 2014; 20:836-42. [PMID: 24940039 PMCID: PMC4057250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 06/11/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Congenital cataracts occur in 3-4 per 10,000 live births and account for 5% to 20% of pediatric blindness worldwide. With more than 37 genes known to be associated with isolated congenital cataract, whole exome sequencing (WES) was recently introduced as an efficient method for screening all known factors. METHODS Whole exome analysis in two members of a four-generation pedigree affected with dominant congenital cataract and glaucoma was performed by WES; co-segregation analysis of identified variants in all pedigree members was completed by Sanger sequencing. RESULTS Analysis of the WES data identified a novel pathogenic variant in EPHA2, c.2925dupC, p.(Ile976Hisfs*37), that demonstrated complete cosegregation with the phenotype in the pedigree. The mutation occurs in the final amino acid before the stop codon of the normal EPHA2 protein and is predicted to produce a mutant protein with an erroneous C-terminal extension of 35 amino acids. Nine other families have been previously reported with dominant congenital/juvenile cataracts and mutations in EPHA2. Two additional likely loss-of-function variants in genes known to cause dominant congenital cataract were considered and excluded based on control data and cosegregation analysis: a nonsense variant in CYRBB3, c.547G>T, p.(Glu183*), and a splicing variant in CRYBA2, c.446+1G>A. CONCLUSIONS Identification of a novel pathogenic EPHA2 allele further implicates this gene in congenital cataract. This is only the second EPHA2 mutation that specifically affects the most C-terminal PSD95/Dlg/ZO1 (PDZ)-binding motif and the third pathogenic allele associated with an erroneous C-terminal extension beyond the normal stop codon.
Collapse
Affiliation(s)
- Linda M. Reis
- Department of Pediatrics and Children’s Research Institute, Medical College of Wisconsin, Milwaukee, WI
| | - Rebecca C. Tyler
- Department of Pediatrics and Children’s Research Institute, Medical College of Wisconsin, Milwaukee, WI
| | - Elena V. Semina
- Department of Pediatrics and Children’s Research Institute, Medical College of Wisconsin, Milwaukee, WI,Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| |
Collapse
|
22
|
Prokudin I, Simons C, Grigg JR, Storen R, Kumar V, Phua ZY, Smith J, Flaherty M, Davila S, Jamieson RV. Exome sequencing in developmental eye disease leads to identification of causal variants in GJA8, CRYGC, PAX6 and CYP1B1. Eur J Hum Genet 2013; 22:907-15. [PMID: 24281366 DOI: 10.1038/ejhg.2013.268] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 10/18/2013] [Accepted: 10/25/2013] [Indexed: 12/13/2022] Open
Abstract
Developmental eye diseases, including cataract/microcornea, Peters anomaly and coloboma/microphthalmia/anophthalmia, are caused by mutations encoding many different signalling and structural proteins in the developing eye. All modes of Mendelian inheritance occur and many are sporadic cases, so provision of accurate recurrence risk information for families and affected individuals is highly challenging. Extreme genetic heterogeneity renders testing for all known disease genes clinically unavailable with traditional methods. We used whole-exome sequencing in 11 unrelated developmental eye disease patients, as it provides a strategy for assessment of multiple disease genes simultaneously. We identified five causative variants in four patients in four different disease genes, GJA8, CRYGC, PAX6 and CYP1B1. This detection rate (36%) is high for a group of patients where clinical testing is frequently not undertaken due to lack of availability and cost. The results affected clinical management in all cases. These variants were detected in the cataract/microcornea and Peters anomaly patients. In two patients with coloboma/microphthalmia, variants in ABCB6 and GDF3 were identified with incomplete penetrance, highlighting the complex inheritance pattern associated with this phenotype. In the coloboma/microphthalmia patients, four other variants were identified in CYP1B1, and CYP1B1 emerged as a candidate gene to be considered as a modifier in coloboma/microphthalmia.
Collapse
Affiliation(s)
- Ivan Prokudin
- 1] Eye and Developmental Genetics Research Group, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia [2] Children's Medical Research Institute, Sydney, NSW, Australia
| | - Cas Simons
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
| | - John R Grigg
- 1] Eye and Developmental Genetics Research Group, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia [2] Discipline of Ophthalmology and Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Rebecca Storen
- 1] Eye and Developmental Genetics Research Group, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia [2] Children's Medical Research Institute, Sydney, NSW, Australia [3] Discipline of Ophthalmology and Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Vikrant Kumar
- Human Genetics, Genome Institute of Singapore, Singapore
| | - Zai Y Phua
- Human Genetics, Genome Institute of Singapore, Singapore
| | - James Smith
- Department of Ophthalmology, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Maree Flaherty
- Department of Ophthalmology, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Sonia Davila
- Human Genetics, Genome Institute of Singapore, Singapore
| | - Robyn V Jamieson
- 1] Eye and Developmental Genetics Research Group, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia [2] Children's Medical Research Institute, Sydney, NSW, Australia [3] Discipline of Ophthalmology and Save Sight Institute, University of Sydney, Sydney, NSW, Australia [4] Disciplines of Paediatrics and Child Health and Genetic Medicine, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
23
|
Pantoja-Melendez C, Ali M, Zenteno JC. An epidemiological investigation of a Forkhead box protein E3 founder mutation underlying the high frequency of sclerocornea, aphakia, and microphthalmia in a Mexican village. Mol Vis 2013; 19:1866-70. [PMID: 24019743 PMCID: PMC3762562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 08/23/2013] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To investigate the molecular epidemiological basis for the unusually high incidence of sclerocornea, aphakia, and microphthalmia in a village in the Tlaxcala province of central Mexico. METHODS A population census was performed in a village to identify all sclerocornea, aphakia, and microphthalmia cases. Molecular analysis of the previously identified Forkhead box protein E3 (FOXE3) mutation, c.292T>C (p.Y98H), was performed with PCR amplification and direct DNA sequencing. In addition, DNA from 405 randomly selected unaffected villagers was analyzed to establish the carrier frequency of the causal mutation. To identify the number of generations since the mutation arose in the village, 17 polymorphic markers distributed in a region of 6 Mb around the mutated locus were genotyped in the affected individuals, followed by DMLE software analysis to calculate mutation age. RESULTS A total of 22 patients with sclerocornea, aphakia, and microphthalmia were identified in the village, rendering a disease prevalence of 2.52 cases per 1,000 habitants (1 in 397). The FOXE3 homozygous mutation was identified in all 17 affected subjects who consented to molecular analysis. Haplotype analysis indicated that the mutation arose 5.0-6.5 generations ago (approximately 106-138 years). Among the 405 unaffected villagers who were genotyped, ten heterozygote carriers were identified, yielding a population carrier frequency of approximately 1 in 40 and a predicted incidence of affected of 1 in 6,400 based on random marriages between two carriers in the village. CONCLUSIONS This study demonstrates that a cluster of patients with sclerocornea, aphakia, and microphthalmia in a small Mexican village is due to a FOXE3 p.Y98H founder mutation that arose in the village just over a century ago at a time when a population migrated from a nearby village because of land disputes. The actual disease incidence is higher than the calculated predicted value and suggests non-random marriages (i.e., consanguinity) within the population. We can now offer the community more informed genetic counseling based on an accurate genetic test, thus increasing the likelihood of a better outcome for the families.
Collapse
Affiliation(s)
- Carlos Pantoja-Melendez
- Research Unit-Genetics, Institute of Ophthalmology, “Conde de Valenciana,” Mexico City, Mexico,Department of Public Health, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Manir Ali
- Leeds Institute of Molecular Medicine, University of Leeds, Leeds, United Kingdom
| | - Juan C. Zenteno
- Research Unit-Genetics, Institute of Ophthalmology, “Conde de Valenciana,” Mexico City, Mexico,Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| |
Collapse
|
24
|
Hamoudi H, Rudnick JC, Prause JU, Tauscher K, Breithaupt A, Teifke JP, Heegaard S. Anterior segment dysgenesis (Peters' anomaly) in two snow leopard (Panthera uncia) cubs. Vet Ophthalmol 2012; 16 Suppl 1:130-4. [DOI: 10.1111/vop.12017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Hassan Hamoudi
- Department of Ophthalmology; University of Copenhagen, Glostrup Hospital; Glostrup Denmark
| | | | - Jan U. Prause
- Department of Neuroscience and Pharmacology, Eye Pathology Institute; University of Copenhagen; Copenhagen Denmark
| | - Kerstin Tauscher
- Friedrich-Löffler-Institut; Bundesforschungsinstitut fuer Tiergesundheit; Greifswald Germany
| | - Angele Breithaupt
- Friedrich-Löffler-Institut; Bundesforschungsinstitut fuer Tiergesundheit; Greifswald Germany
| | - Jens P. Teifke
- Friedrich-Löffler-Institut; Bundesforschungsinstitut fuer Tiergesundheit; Greifswald Germany
| | - Steffen Heegaard
- Department of Ophthalmology; University of Copenhagen, Glostrup Hospital; Glostrup Denmark
- Department of Neuroscience and Pharmacology, Eye Pathology Institute; University of Copenhagen; Copenhagen Denmark
| |
Collapse
|
25
|
Klauer AA, van Hoof A. Degradation of mRNAs that lack a stop codon: a decade of nonstop progress. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 3:649-60. [PMID: 22740367 DOI: 10.1002/wrna.1124] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nonstop decay is the mechanism of identifying and disposing aberrant transcripts that lack in-frame stop codons. It is hypothesized that these transcripts are identified during translation when the ribosome arrives at the 3' end of the mRNA and stalls. Presumably, the ribosome stalling recruits additional cofactors, Ski7 and the exosome complex. The exosome degrades the transcript using either one of its ribonucleolytic activities, and the ribosome and the peptide are both released. Additional precautionary measures by the nonstop decay pathway may include translational repression of the nonstop transcript after translation, and proteolysis of the released peptide by the proteasome. This surveillance mechanism protects the cells from potentially harmful truncated proteins, but it may also be involved in mediating critical cellular functions of transcripts that are prone to stop codon read-through. Important advances have been made in the past decade as we learn that nonstop decay may have implications in human disease.
Collapse
Affiliation(s)
- A Alejandra Klauer
- Microbiology and Molecular Genetics, University of Texas Health Science University-Houston, Houston, TX, USA
| | | |
Collapse
|
26
|
Zhao J, Kawai K, Wang H, Wu D, Wang M, Yue Z, Zhang J, Liu YH. Loss of Msx2 function down-regulates the FoxE3 expression and results in anterior segment dysgenesis resembling Peters anomaly. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:2230-9. [PMID: 22503753 DOI: 10.1016/j.ajpath.2012.02.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 01/18/2012] [Accepted: 02/13/2012] [Indexed: 10/28/2022]
Abstract
Complex molecular interactions dictate the developmental steps that lead to a mature and functional cornea and lens. Peters anomaly is one subtype of anterior segment dysgenesis especially due to abnormal development of the cornea and lens. MSX2 was recently implicated as a potential gene that is critical for anterior segment development. However, the role of MSX2 within the complex mechanisms of eye development remains elusive. Our present study observed the morphologic changes in conventional Msx2 knockout (KO) mice and found phenotypes consistent with Peters anomaly and microphthalmia seen in humans. The role of Msx2 in cornea and lens development was further investigated using IHC, in situ hybridization, and quantification of proliferative and apoptotic lens cells. Loss of Msx2 down-regulated FoxE3 expression and up-regulated Prox1 and crystallin expression in the lens. The FoxE3 and Prox1 malfunction and precocious Prox1 and crystallin expression contribute to a disturbed lens cell cycle in lens vesicles and eventually to cornea-lentoid adhesions and microphthalmia in Msx2 KO mice. The observed changes in the expression of FoxE3 suggest that Msx2 is an important contributor in controlling transcription of target genes critical for early eye development. These results provide the first direct genetic evidence of the involvement of MSX2 in Peters anomaly and the distinct function of MSX2 in regulating the growth and development of lens vesicles.
Collapse
Affiliation(s)
- Jiangyue Zhao
- Eye Hospital of China Medical University and the Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Provincial Key Laboratory of Lens Research, Liaoning, China.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
PURPOSE OF REVIEW Anterior segment dysgenesis (ASD) disorders encompass a spectrum of developmental conditions affecting the cornea, iris, and lens and are generally associated with an approximate 50% risk for glaucoma. These conditions are characterized by both autosomal dominant and recessive patterns of inheritance often with incomplete penetrance/variable expressivity. This article summarizes what is known about the genetics of ASD disorders and reviews recent developments. RECENT FINDINGS Mutations in Collagen type IV alpha-1 (COL4A1) and Beta-1,3-galactosyltransferase-like (B3GALTL) have been reported in ASD patients. Novel findings in other well known ocular genes are also presented, among which regulatory region deletions in PAX6 and PITX2 are most notable. SUMMARY Although a number of genetic causes have been identified, many ASD conditions are still awaiting genetic elucidation. The majority of characterized ASD genes encode transcription factors; several other genes represent extracellular matrix-related proteins. All of the involved genes play active roles in ocular development and demonstrate conserved functions across species. The use of novel technologies, such as whole genome sequencing/comparative genomic hybridization, is likely to broaden the mutation spectrums in known genes and assist in the identification of novel causative genes as well as modifiers explaining the phenotypic variability of ASD conditions.
Collapse
|
28
|
Hamby SE, Thomas NST, Cooper DN, Chuzhanova N. A meta-analysis of single base-pair substitutions in translational termination codons ('nonstop' mutations) that cause human inherited disease. Hum Genomics 2011; 5:241-64. [PMID: 21712188 PMCID: PMC3525242 DOI: 10.1186/1479-7364-5-4-241] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
'Nonstop' mutations are single base-pair substitutions that occur within translational termination (stop) codons and which can lead to the continued and inappropriate translation of the mRNA into the 3'-untranslated region. We have performed a meta-analysis of the 119 nonstop mutations (in 87 different genes) known to cause human inherited disease, examining the sequence context of the mutated stop codons and the average distance to the next alternative in-frame stop codon downstream, in comparison with their counterparts from control (non-mutated) gene sequences. A paucity of alternative in-frame stop codons was noted in the immediate vicinity (0-49 nucleotides downstream) of the mutated stop codons as compared with their control counterparts (p = 7.81 × 10-4). This implies that at least some nonstop mutations with alternative stop codons in close proximity will not have come to clinical attention, possibly because they will have given rise to stable mRNAs (not subject to nonstop mRNA decay) that are translatable into proteins of near-normal length and biological function. A significant excess of downstream in-frame stop codons was, however, noted in the range 150-199 nucleotides from the mutated stop codon (p = 8.55 × 10-4). We speculate that recruitment of an alternative stop codon at greater distance from the mutated stop codon may trigger nonstop mRNA decay, thereby decreasing the amount of protein product and yielding a readily discernible clinical phenotype. Confirmation or otherwise of this postulate must await the emergence of a clearer understanding of the mechanism of nonstop mRNA decay in mammalian cells.
Collapse
Affiliation(s)
- Stephen E Hamby
- School of Science and Technology, Nottingham Trent University, UK
| | | | | | | |
Collapse
|
29
|
Khan K, Rudkin A, Parry D, Burdon K, McKibbin M, Logan C, Abdelhamed Z, Muecke J, Fernandez-Fuentes N, Laurie K, Shires M, Fogarty R, Carr I, Poulter J, Morgan J, Mohamed M, Jafri H, Raashid Y, Meng N, Piseth H, Toomes C, Casson R, Taylor G, Hammerton M, Sheridan E, Johnson C, Inglehearn C, Craig J, Ali M. Homozygous mutations in PXDN cause congenital cataract, corneal opacity, and developmental glaucoma. Am J Hum Genet 2011; 89:464-73. [PMID: 21907015 PMCID: PMC3169830 DOI: 10.1016/j.ajhg.2011.08.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 07/29/2011] [Accepted: 08/09/2011] [Indexed: 11/17/2022] Open
Abstract
Anterior segment dysgenesis describes a group of heterogeneous developmental disorders that affect the anterior chamber of the eye and are associated with an increased risk of glaucoma. Here, we report homozygous mutations in peroxidasin (PXDN) in two consanguineous Pakistani families with congenital cataract-microcornea with mild to moderate corneal opacity and in a consanguineous Cambodian family with developmental glaucoma and severe corneal opacification. These results highlight the diverse ocular phenotypes caused by PXDN mutations, which are likely due to differences in genetic background and environmental factors. Peroxidasin is an extracellular matrix-associated protein with peroxidase catalytic activity, and we confirmed localization of the protein to the cornea and lens epithelial layers. Our findings imply that peroxidasin is essential for normal development of the anterior chamber of the eye, where it may have a structural role in supporting cornea and lens architecture as well as an enzymatic role as an antioxidant enzyme in protecting the lens, trabecular meshwork, and cornea against oxidative damage.
Collapse
Affiliation(s)
- Kamron Khan
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
- Eye Department, St James University Hospital, Leeds LS9 7TF, UK
| | - Adam Rudkin
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA 5042, Australia
| | - David A. Parry
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| | - Kathryn P. Burdon
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA 5042, Australia
| | - Martin McKibbin
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
- Eye Department, St James University Hospital, Leeds LS9 7TF, UK
| | - Clare V. Logan
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| | - Zakia I.A. Abdelhamed
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
- Anatomy and Embryology Department, Al-Azhar University, Nasr City District 7, Cairo, Egypt
| | - James S. Muecke
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
| | | | - Kate J. Laurie
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA 5042, Australia
| | - Mike Shires
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| | - Rhys Fogarty
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA 5042, Australia
| | - Ian M. Carr
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| | | | | | - Moin D. Mohamed
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
- St Thomas' Hospital, London SE1 7EH, UK
| | - Hussain Jafri
- Gene Technology Laboratories 146/1, Shadman Jail Road, Lahore 54000, Pakistan
| | - Yasmin Raashid
- Department of Obstetrics and Gynaecology, King Edward Medical University, Lahore 54000, Pakistan
| | - Ngy Meng
- Preah Ang Duong Eye Hospital, Phnom Penh 855, Cambodia
| | - Horm Piseth
- Fred Hollows Foundation, Phnom Penh 518, Cambodia
| | - Carmel Toomes
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| | - Robert J. Casson
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
| | | | - Michael Hammerton
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
| | | | | | | | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA 5042, Australia
| | - Manir Ali
- Leeds Institute of Molecular Medicine, Leeds LS9 7TF, UK
| |
Collapse
|
30
|
Khan K, Al-Maskari A, McKibbin M, Carr IM, Booth A, Mohamed M, Siddiqui S, Poulter JA, Parry DA, Logan CV, Hashmi A, Sahi T, Jafri H, Raashid Y, Johnson CA, Markham AF, Toomes C, Rice A, Sheridan E, Inglehearn CF, Ali M. Genetic heterogeneity for recessively inherited congenital cataract microcornea with corneal opacity. Invest Ophthalmol Vis Sci 2011; 52:4294-9. [PMID: 21474777 DOI: 10.1167/iovs.10-6776] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate whether three consanguineous families from the Punjab province of Pakistan, with affected members with recessively inherited congenital cataract microcornea with corneal opacity, are genetically homogeneous. METHODS An ophthalmic examination was performed on each family member to establish the diagnosis. The two largest families were analyzed by homozygosity mapping using SNP arrays. Linkage was confirmed using polymorphic microsatellite markers, and logarithm of odds (LOD) scores were calculated. Candidate genes were prioritized using the ENDEAVOUR program. RESULTS Autosomal recessive congenital cataract-microcornea with corneal opacity mapped to chromosome 10cen for family MEP57 and to either chromosomes 2ptel or 20p for family MEP60. For MEP57, the refined interval was 36.8 Mb flanked by D10S1208 (35.3 Mb) and D10S676 (72.1 Mb). For MEP60, the interval containing the mutation was either 6.7 Mb from the telomere of chromosome 2 to marker D2S281 or 3.8 Mb flanked by D20S906 (1.5 Mb) and D20S835 (5.3 Mb). Maximum multipoint LOD scores of 3.09, 1.94, and 3.09 were calculated at D10S567, D2S281, and D20S473 for families MEP57 and MEP60. Linkage to these loci was excluded for family MEP68. SLC4A11 was excluded as a candidate gene for the observed phenotype in MEP60. CONCLUSIONS The authors have identified two new loci, one on chromosome 10cen and the other on 2ptel or 20p, that are associated with recessively inherited congenital cataract-microcornea with corneal opacity. This phenotype is genetically heterogeneous in the Pakistani population. Further genetic studies of this kind, combined with a detailed phenotypic description, will contribute to more precise classification criteria for anterior segment disease.
Collapse
Affiliation(s)
- Kamron Khan
- Leeds Institute of Molecular Medicine, Leeds, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|