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Maxwell G, Souzeau E. Childhood glaucoma: Implications for genetic counselling. Clin Genet 2024. [PMID: 39206700 DOI: 10.1111/cge.14603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 07/17/2024] [Accepted: 07/23/2024] [Indexed: 09/04/2024]
Abstract
Childhood glaucoma is a heterogeneous group of ocular disorders defined by an age of onset from birth to 18 years. These vision-threatening disorders require early diagnosis, timely treatment, and lifelong management to maintain vision and minimise irreversible blindness. The genetics of childhood glaucoma is complex with both phenotypic and genetic heterogeneity. The purpose of this review is to summarise the different types of childhood glaucoma and their genetic architecture to aid in the genetic counselling process with patients and their families. We provide an overview of associated syndromes and discuss implications for genetic counselling, including genetic testing strategies, cascade genetic testing, and reproductive options.
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Affiliation(s)
- Giorgina Maxwell
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
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Fuse N, Kimura M, Shimizu A, Koshiba S, Hamanaka T, Nakamura M, Ishida N, Sakai H, Ikeda Y, Mori K, Endo A, Nagasaki M, Katsuoka F, Yasuda J, Matsubara Y, Nakazawa T, Yamamoto M. Mutations of CYP1B1 and FOXC1 genes for childhood glaucoma in Japanese individuals. Jpn J Ophthalmol 2024:10.1007/s10384-024-01103-0. [PMID: 39158757 DOI: 10.1007/s10384-024-01103-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 06/20/2024] [Indexed: 08/20/2024]
Abstract
PURPOSE To explore the frequency and positions of genetic mutations in CYP1B1 and FOXC1 in a Japanese population. STUDY DESIGN Molecular genetic analysis. METHODS Genomic DNA was extracted from 31 Japanese patients with childhood glaucoma (CG) from 29 families. We examined the CYP1B, FOXC1, and MYOC genes using Sanger sequencing and whole-exome sequencing (WES). RESULTS For CYP1B1, we identified 9 families that harbored novel mutations, p.A202T, p.D274E, p.Q340*, and p.V420G; the remaining mutations had been previously reported. When mapped to the CYP1B1 protein structure, all mutations appeared to influence the enzymatic activity of CYP1B1 by provoking structural deformity. Five patients were homozygotes or compound heterozygotes, supporting the recessive inheritance of the CYP1B1 mutations in CG. In contrast, four patients were heterozygous for the CYP1B1 mutation, suggesting the presence of regulatory region mutations or strong modifiers. For the FOXC1 gene, we identified 3 novel mutations, p.Q23fs, p.Q70R, and p.E163*, all of which were identified in a heterozygous state. No mutation was found in the MYOC gene in these CG patients. All individuals with CYP1B1 and FOXC1 mutations were severely affected by early-onset CG. In the CYP1B1-, FOXC1-, and MYOC-negative families, we also searched for variants in the other candidate genes reported for CG through WES, but could not find any mutations in these genes. CONCLUSIONS Our analyses of 29 CG families revealed 9 families with point mutations in the CYP1B1 gene, and four of those patients appeared to be heterozygotes, suggesting the presence of complex pathogenic mechanisms. FOXC1 appears to be another major causal gene of CG, indicating that panel sequencing of CYP1B1 and FOXC1 will be useful for diagnosis of CG in Japanese individuals.
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Affiliation(s)
- Nobuo Fuse
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan.
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo- machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan.
| | - Masae Kimura
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
| | - Ai Shimizu
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo- machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan
| | - Seizo Koshiba
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
| | - Teruhiko Hamanaka
- Department of Ophthalmology, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuyaku, 150-8935, Tokyo, Japan
| | - Makoto Nakamura
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, 650-0017, Kobe, Japan
| | - Nobuo Ishida
- Ishida Eye Clinic, 2-2-31 Honcho, Joetsu-shi, Niigata, 943-0832, Japan
| | - Hiroshi Sakai
- Urasoe Sakai Eye Clinic, 6-1-21 Miyagi, Urasoe, 901-2126, Okinawa, Japan
| | - Yoko Ikeda
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kawaramachi Hirokouji, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Kazuhiko Mori
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kawaramachi Hirokouji, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Atsushi Endo
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
- Altech Corporation, Muscat Building 6F, 3-7-13, Nagamachi, Taihaku-ku, Sendai, 982-0011, Miyagi, Japan
| | - Masao Nagasaki
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
- Human Biosciences Unit for the Top Global Course Center for the Promotion of Interdisciplinary Education and Research (CPIER), Kyoto University, 53, Shogoinkawahara-cho, Sakyo-ku, Kyoto City, 606-8507, Kyoto, Japan
| | - Fumiki Katsuoka
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
| | - Jun Yasuda
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
| | - Yoichi Matsubara
- National Center for Child Health and Development, Research Institute 2-10-1 Okura Setagaya-ku, Tokyo, 157-8535, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo- machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan
| | - Masayuki Yamamoto
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, 2-1 Seiryo- machi, Aoba-ku, Sendai, 980-8573, Miyagi, Japan
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Al-Saei O, Malka S, Owen N, Aliyev E, Vempalli FR, Ocieczek P, Al-Khathlan B, Fakhro K, Moosajee M. Increasing the diagnostic yield of childhood glaucoma cases recruited into the 100,000 Genomes Project. BMC Genomics 2024; 25:484. [PMID: 38755526 PMCID: PMC11097485 DOI: 10.1186/s12864-024-10353-8] [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: 12/22/2023] [Accepted: 04/25/2024] [Indexed: 05/18/2024] Open
Abstract
Childhood glaucoma (CG) encompasses a heterogeneous group of genetic eye disorders that is responsible for approximately 5% of childhood blindness worldwide. Understanding the molecular aetiology is key to improving diagnosis, prognosis and unlocking the potential for optimising clinical management. In this study, we investigated 86 CG cases from 78 unrelated families of diverse ethnic backgrounds, recruited into the Genomics England 100,000 Genomes Project (GE100KGP) rare disease cohort, to improve the genetic diagnostic yield. Using the Genomics England/Genomic Medicine Centres (GE/GMC) diagnostic pipeline, 13 unrelated families were solved (13/78, 17%). Further interrogation using an expanded gene panel yielded a molecular diagnosis in 7 more unrelated families (7/78, 9%). This analysis effectively raises the total number of solved CG families in the GE100KGP to 26% (20/78 families). Twenty-five percent (5/20) of the solved families had primary congenital glaucoma (PCG), while 75% (15/20) had secondary CG; 53% of this group had non-acquired ocular anomalies (including iris hypoplasia, megalocornea, ectopia pupillae, retinal dystrophy, and refractive errors) and 47% had non-acquired systemic diseases such as cardiac abnormalities, hearing impairment, and developmental delay. CYP1B1 was the most frequently implicated gene, accounting for 55% (11/20) of the solved families. We identified two novel likely pathogenic variants in the TEK gene, in addition to one novel pathogenic copy number variant (CNV) in FOXC1. Variants that passed undetected in the GE100KGP diagnostic pipeline were likely due to limitations of the tiering process, the use of smaller gene panels during analysis, and the prioritisation of coding SNVs and indels over larger structural variants, CNVs, and non-coding variants.
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Affiliation(s)
- Omayma Al-Saei
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
- Department of Human Genetics, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Samantha Malka
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Nicholas Owen
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Elbay Aliyev
- Department of Human Genetics, Sidra Medicine, PO Box 26999, Doha, Qatar
| | | | - Paulina Ocieczek
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | | | - Khalid Fakhro
- Department of Human Genetics, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK.
- The Francis Crick Institute, London, NW1 1AT, UK.
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Pan Y, Iwata T. Exploring the Genetic Landscape of Childhood Glaucoma. CHILDREN (BASEL, SWITZERLAND) 2024; 11:454. [PMID: 38671671 PMCID: PMC11048810 DOI: 10.3390/children11040454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/03/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024]
Abstract
Childhood glaucoma, a significant cause of global blindness, represents a heterogeneous group of disorders categorized into primary or secondary forms. Primary childhood glaucoma stands as the most prevalent subtype, comprising primary congenital glaucoma (PCG) and juvenile open-angle glaucoma (JOAG). Presently, multiple genes are implicated in inherited forms of primary childhood glaucoma. This comprehensive review delves into genetic investigations into primary childhood glaucoma, with a focus on identifying causative genes, understanding their inheritance patterns, exploring essential biological pathways in disease pathogenesis, and utilizing animal models to study these mechanisms. Specifically, attention is directed towards genes such as CYP1B1 (cytochrome P450 family 1 subfamily B member 1), LTBP2 (latent transforming growth factor beta binding protein 2), TEK (TEK receptor tyrosine kinase), ANGPT1 (angiopoietin 1), and FOXC1 (forkhead box C1), all associated with PCG; and MYOC (myocilin), associated with JOAG. Through exploring these genetic factors, this review aims to deepen our understanding of the intricate pathogenesis of primary childhood glaucoma, thereby facilitating the development of enhanced diagnostic and therapeutic strategies.
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Affiliation(s)
| | - Takeshi Iwata
- National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo 152-8902, Japan;
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Bozkurt B, Bağcı O, Üzüm S, Çora T. A novel LTBP2 gene variant in a Turkish family with juvenile-onset open-angle glaucoma. Ophthalmic Genet 2024:1-6. [PMID: 38557215 DOI: 10.1080/13816810.2024.2331540] [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: 10/17/2023] [Accepted: 03/12/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Juvenile-onset open-angle glaucoma (JOAG) is a rare form of primary open-angle glaucoma (POAG) with an early age of onset before 40 years. Latent transforming growth factor-beta binding protein 2 (LTBP-2) is an extracellular matrix protein with a multi-domain structure and homology to fibrillins. LTBP2 gene variants have been associated with JOAG in a small number of patients. Herein, we report a novel missense variant in the LTBP2 gene in a Turkish family with JOAG. MATERIALS AND METHODS Blood samples were obtained from three siblings (a 20-year-old woman with JOAG, 26-year-old man with JOAG, and 15-year-old girl with posterior embryotoxon) for genetic analysis. Their father had moderate-severe POAG and the 24-year-old brother had JOAG. The mother and 32-year-old sister were healthy. Although the parents reported no consanguinity, they come from the same village. RESULTS Clinical exome sequencing analysis of the two siblings with JOAG revealed a novel c.607C>T p.(R203C) (rs777450651) homozygous LTBP2 variant, while the variant was heterozygous in their 15-year-old sister. There were no mutations in the MYOC, CYP1B1, or FBN1 genes. CONCLUSION We documented a novel missense mutation in the LTBP2 gene leading to a severe form of JOAG with refractory IOP and progressive optic nerve damage, which seems to show autosomal recessive inheritance.
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Affiliation(s)
- Banu Bozkurt
- Department of Ophthalmology, Selçuk University Faculty of Medicine, Konya, Türkiye
| | - Ozkan Bağcı
- Department of Medical Genetics, Selçuk University Faculty of Medicine, Konya, Türkiye
| | - Sema Üzüm
- Department of Ophthalmology, Selçuk University Faculty of Medicine, Konya, Türkiye
| | - Tülin Çora
- Department of Medical Genetics, Selçuk University Faculty of Medicine, Konya, Türkiye
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Kumar A, Han Y, Oatts JT. Genetic changes and testing associated with childhood glaucoma: A systematic review. PLoS One 2024; 19:e0298883. [PMID: 38386645 PMCID: PMC10883561 DOI: 10.1371/journal.pone.0298883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
Many forms of childhood glaucoma have been associated with underlying genetic changes, and variants in many genes have been described. Currently, testing is variable as there are no widely accepted guidelines for testing. This systematic review aimed to summarize the literature describing genetic changes and testing practices in childhood glaucoma. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) 2020 guidelines and registered with Prospero (ID CRD42023400467). A comprehensive review of Pubmed, Embase, and Cochrane databases was performed from inception through March 2, 2023 using the search terms: (glaucoma) AND (pediatric OR childhood OR congenital OR child OR infant OR infantile) AND (gene OR genetic OR genotype OR locus OR genomic OR mutation OR variant OR test OR screen OR panel). Information was extracted regarding genetic variants including genotype-phenotype correlation. Risk of bias was assessed using the Newcastle-Ottawa Scale. Of 1,916 records screened, 196 studies met inclusion criteria and 53 genes were discussed. Among study populations, mean age±SD at glaucoma diagnosis was 8.94±9.54 years and 50.4% were male. The most common gene discussed was CYP1B1, evaluated in 109 (55.6%) studies. CYP1B1 variants were associated with region and population-specific prevalence ranging from 5% to 86% among those with primary congenital glaucoma. MYOC variants were discussed in 31 (15.8%) studies with prevalence up to 36% among patients with juvenile open angle glaucoma. FOXC1 variants were discussed in 25 (12.8%) studies, which demonstrated phenotypic severity dependent on degree of gene expression and type of mutation. Overall risk of bias was low; the most common domains of bias were selection and comparability. Numerous genes and genetic changes have been associated with childhood glaucoma. Understanding the most common genes as well as potential genotype-phenotype correlation has the potential to improve diagnostic and prognostic outcomes for children with glaucoma.
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Affiliation(s)
- Anika Kumar
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Ying Han
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Julius T. Oatts
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
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Shen R, Li VSW, Wong MOM, Chan PPM. Pediatric Glaucoma-From Screening, Early Detection to Management. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10020181. [PMID: 36832310 PMCID: PMC9954748 DOI: 10.3390/children10020181] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Pediatric glaucoma (PG) covers a rare and heterogeneous group of diseases with variable causes and presentations. Delayed diagnosis of PG could lead to blindness, bringing emotional and psychological burdens to patients' caregivers. Recent genetic studies identified novel causative genes, which may provide new insight into the etiology of PG. More effective screening strategies could be beneficial for timely diagnosis and treatment. New findings on clinical characteristics and the latest examination instruments have provided additional evidence for diagnosing PG. In addition to IOP-lowering therapy, managing concomitant amblyopia and other associated ocular pathologies is essential to achieve a better visual outcome. Surgical treatment is usually required although medication is often used before surgery. These include angle surgeries, filtering surgeries, minimally invasive glaucoma surgeries, cyclophotocoagulation, and deep sclerectomy. Several advanced surgical therapies have been developed to increase success rates and decrease postoperative complications. Here, we review the classification and diagnosis, etiology, screening, clinical characteristics, examinations, and management of PG.
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Affiliation(s)
- Ruyue Shen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Venice S. W. Li
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Mandy O. M. Wong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Poemen P. M. Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
- Lam Kin Chung. Jet King-Shing Ho Glaucoma Treatment and Research Centre, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong, China
- Correspondence: ; Tel.: +852-3943-5807
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Roodnat AW, Callaghan B, Doyle C, Henry M, Goljanek-Whysall K, Simpson DA, Sheridan C, Atkinson SD, Willoughby CE. Genome-Wide RNA Sequencing of Human Trabecular Meshwork Cells Treated with TGF-β1: Relevance to Pseudoexfoliation Glaucoma. Biomolecules 2022; 12:1693. [PMID: 36421707 PMCID: PMC9687758 DOI: 10.3390/biom12111693] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/15/2022] [Accepted: 11/10/2022] [Indexed: 08/11/2023] Open
Abstract
Pseudoexfoliation glaucoma (XFG) is an aggressive form of secondary open angle glaucoma, characterised by the production of exfoliation material and is estimated to affect 30 million people worldwide. Activation of the TGF-β pathway by TGF-β1 has been implicated in the pathogenesis of pseudoexfoliation glaucoma. To further investigate the role of TGF-β1 in glaucomatous changes in the trabecular meshwork (TM), we used RNA-Seq to determine TGF-β1 induced changes in the transcriptome of normal human trabecular meshwork (HTM) cells. The main purpose of this study was to perform a hypothesis-independent RNA sequencing analysis to investigate genome-wide alterations in the transcriptome of normal HTMs stimulated with TGF-β1 and investigate possible pathophysiological mechanisms driving XFG. Our results identified multiple differentially expressed genes including several genes known to be present in exfoliation material. Significantly altered pathways, biological processes and molecular functions included extracellular matrix remodelling, Hippo and Wnt pathways, the unfolded protein response, oxidative stress, and the antioxidant system. This cellular model of pseudoexfoliation glaucoma can provide insight into disease pathogenesis and support the development of novel therapeutic interventions.
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Affiliation(s)
- Anton W. Roodnat
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine Campus, Coleraine BT52 1SA, Northern Ireland, UK
- Personalised Medicine Centre, Ulster University, Londonderry BT47 6SB, Northern Ireland, UK
| | - Breedge Callaghan
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine Campus, Coleraine BT52 1SA, Northern Ireland, UK
| | - Chelsey Doyle
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine Campus, Coleraine BT52 1SA, Northern Ireland, UK
| | - Megan Henry
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine Campus, Coleraine BT52 1SA, Northern Ireland, UK
| | - Katarzyna Goljanek-Whysall
- School of Medicine, Physiology, National University of Ireland Galway, H91 W5P7 Galway, Ireland
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, England, UK
| | - David A. Simpson
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University, Belfast BT9 7BL, Northern Ireland, UK
| | - Carl Sheridan
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, England, UK
| | - Sarah D. Atkinson
- Personalised Medicine Centre, Ulster University, Londonderry BT47 6SB, Northern Ireland, UK
| | - Colin E. Willoughby
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine Campus, Coleraine BT52 1SA, Northern Ireland, UK
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, England, UK
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Next-generation whole exome sequencing to delineate the genetic basis of primary congenital glaucoma. Sci Rep 2022; 12:17218. [PMID: 36241656 PMCID: PMC9568502 DOI: 10.1038/s41598-022-20939-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 09/21/2022] [Indexed: 01/06/2023] Open
Abstract
To delineate the genetic bases of primary congenital glaucoma (PCG), we ascertained a large cohort consisting of 48 consanguineous families. Of these, we previously reported 26 families with mutations in CYP1B1 and six families with LTBP2, whereas the genetic bases responsible for PCG in 16 families remained elusive. We employed next-generation whole exome sequencing to delineate the genetic basis of PCG in four of these 16 familial cases. Exclusion of linkage to reported PCG loci was established followed by next-generation whole exome sequencing, which was performed on 10 affected individuals manifesting cardinal systems of PCG belonging to four unresolved families along with four control samples consisting of genomic DNAs of individuals harboring mutations in CYP1B1 and LTBP2. The analyses of sequencing datasets failed to identify potential causal alleles in the 10 exomes whereas c.1169G > A (p. Arg390His) in CYP1B1 and c.3427delC (p.Gln1143Argfs*35) in LTBP2 were identified in the control samples. Taken together, next-generation whole exome sequencing failed to delineate the genetic basis of PCG in familial cases excluded from mutations in CYP1B1 and LTBP2. These data strengthen the notion that compound heterozygous coding variants or non-coding variants might contribute to PCG.
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Knight LS, Mullany S, Taranath DA, Ruddle JB, Barnett CP, Sallevelt SC, Berry EC, Marshall HN, Hollitt GL, Souzeau E, Craig JE, Siggs OM. The phenotypic spectrum of ADAMTSL4-associated ectopia lentis: Additional cases, complications, and review of literature. Mol Vis 2022; 28:257-268. [PMID: 36284667 PMCID: PMC9514546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 09/02/2022] [Indexed: 11/02/2022] Open
Abstract
Purpose ADAMTSL4-associated ectopia lentis is a rare autosomal recessive condition that is primarily associated with crystalline lens displacement. However, the prevalence of other ocular and systemic manifestations of this condition is poorly understood. In this study, we summarize the ocular and systemic phenotypic spectrum of this condition. Methods A cross-sectional case study series of four individuals with biallelic pathogenic or likely pathogenic ADAMTSL4 variants was performed alongside a literature review of individuals with ADAMTSL4-associated ectopia lentis on September 29, 2021. Ocular and systemic findings, complications, and genetic findings of all four individuals were collected and summarized. Results The phenotypic spectrum across 91 individuals sourced from literature and four individuals from this case study series was highly variable. The main ocular phenotypes included ectopia lentis (95/95, 100%), ectopia lentis et pupillae (18/95, 19%), iris transillumination (13/95, 14%), iridodonesis (12/95, 13%), persistent pupillary membrane (12/95, 13%), and early-onset cataract or lens opacities (12/95, 13%). Anterior segment features other than ectopia lentis appeared to be exclusively associated with biallelic loss of function variants (p<0.001). Pupillary block glaucoma had a prevalence of 1%. Post-lensectomy complications included retinal detachment (6/41, 15%), elevated intraocular pressure (4/41, 10%), and aphakic glaucoma (1/41, 2%). Most individuals were not reported to have had systemic features (69/95, 73%). Conclusions The clinical phenotype of ADAMTSL4-associated ectopia lentis was summarized and expanded. Clinicians should be aware of the varied ocular phenotype and the risks of retinal detachment, ocular hypertension, and glaucoma in the diagnosis and management of this condition.
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Affiliation(s)
- Lachlan S.W. Knight
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Sean Mullany
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Deepa A. Taranath
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Jonathan B. Ruddle
- Department of Ophthalmology, Royal Children’s Hospital, Parkville, Australia,Ophthalmology, University of Melbourne, Department of Surgery, Parkville, Australia,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Christopher P. Barnett
- Paediatric and Reproductive Genetics Unit, Women’s and Children’s Hospital, North Adelaide, Australia
| | - Suzanne C.E.H. Sallevelt
- Paediatric and Reproductive Genetics Unit, Women’s and Children’s Hospital, North Adelaide, Australia
| | - Ella C. Berry
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Henry N. Marshall
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Georgina L. Hollitt
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Owen M. Siggs
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia,Garvan Institute of Medical Research, Darlinghurst, Australia
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11
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Genetics in primary congenital glaucoma: Implications in disease management and counseling. Eur J Med Genet 2021; 65:104378. [PMID: 34748994 DOI: 10.1016/j.ejmg.2021.104378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 06/10/2021] [Accepted: 11/02/2021] [Indexed: 11/21/2022]
Abstract
Primary congenital glaucoma is an important cause of visual impairment in children. It can develop both pre- and postnatally. Angle surgery is the first line treatment modality. If the disease remains untreated or if the diagnosis is delayed, it can lead to irreversible visual loss and blindness. The genetics of primary congenital glaucoma are complex and not yet entirely understood. At present multiple disease-causing genes have been identified. CYP1B1 is the most well known gene causing autosomal recessive congenital glaucoma. Other genes have been found to play a role through recessive, dominant or polygenic mechanisms. Here we provide an overview of the known genes and mechanisms described in patients with PCG. Furthermore, we provide a practical counseling and follow-up guideline for relatives of a proband.
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Gupta V, Somarajan BI, Kaur G, Gupta S, Singh R, Pradhan D, Singh H, Kaur P, Sharma A, Chawla B, Pahuja A, Ramachandran R, Sharma A. Exome sequencing identifies procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 mutations in primary congenital and juvenile glaucoma. Indian J Ophthalmol 2021; 69:2710-2716. [PMID: 34571620 PMCID: PMC8597539 DOI: 10.4103/ijo.ijo_1750_21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To report the association of procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) mutations with bilateral primary congenital glaucoma (PCG) in monozygotic twins and with nondominant juvenile-onset primary open-angle glaucoma (JOAG). METHODS We utilized family-based whole-exome sequencing to detect disease-causing mutations in a pair of monozygotic twins with de-novo PCG and compared its existence in 50 nonfamilial cases of JOAG and 30 healthy controls. To validate the identified mutations, direct Sanger sequencing was performed. For further evaluation of gene expression in the ocular tissues, we performed whole-mount in situ hybridization in zebrafish embryos. RESULTS We identified a novel missense mutation (c.1925A>G, p.Tyr642Cys) in the PLOD2 gene in the monozygotic twin pair with PCG and another missense mutation (c.1880G>A, p.Arg627Gln) in one JOAG patient. Both mutations identified were heterozygous. Neither the parents of the twins nor the parents of the JOAG patient harbored the mutation and it was probably a de-novo change. The zebrafish in situ hybridization revealed expression of the PLOD2 gene during embryogenesis of the eye. CONCLUSION We observed an association of PLOD2 mutations with PCG and with nonfamilial JOAG. This new gene needs to be further investigated for its role in pathways associated with glaucoma pathogenesis.
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Affiliation(s)
- Viney Gupta
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India
| | | | - Gagandeep Kaur
- Public Health Foundation of India (PHFI), New Delhi, India
| | - Shikha Gupta
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India
| | - Renu Singh
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India
| | - Dibyabhaba Pradhan
- Division of Biomedical Informatics, Indian Council of Medical Research, Mohali, Punjab, India
| | - Harpreet Singh
- Division of Biomedical Informatics, Indian Council of Medical Research, Mohali, Punjab, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, Mohali, Punjab, India
| | - Anshul Sharma
- Department of Anatomy, All India Institute of Medical Sciences, Mohali, Punjab, India
| | - Bindia Chawla
- Department of Biology, Indian Institute of Scientific and Educational Research (IISER), Mohali, Punjab, India
| | - Anisha Pahuja
- Department of Biology, Indian Institute of Scientific and Educational Research (IISER), Mohali, Punjab, India
| | - Rajesh Ramachandran
- Department of Biology, Indian Institute of Scientific and Educational Research (IISER), Mohali, Punjab, India
| | - Arundhati Sharma
- Department of Anatomy, All India Institute of Medical Sciences, Mohali, Punjab, India
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Zhu AY, Costain G, Cytrynbaum C, Weksberg R, Cohn RD, Ali A. Novel heterozygous variants in PXDN cause different anterior segment dysgenesis phenotypes in monozygotic twins. Ophthalmic Genet 2021; 42:624-630. [PMID: 33985410 DOI: 10.1080/13816810.2021.1925929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Since bi-allelic variants in the PXDN gene were first discovered in 2011 to be associated with anterior segment dysgenesis, a spectrum of ophthalmologic and systemic clinical manifestations has been described. This manuscript reports two distinct clinical phenotypes in monozygotic twin sisters, including the previously unreported ocular manifestation of bilateral primary aphakia, associated with novel compound heterozygous variants in the PXDN gene. MATERIALS AND METHODS We used genome sequencing to study a non-consanguineous family with monozygotic twin sister probands: one presenting with bilateral microphthalmia, primary aphakia, total corneal opacification, congenital glaucoma, and complex systemic comorbidities; the other with anterior persistent fetal vasculature in the right eye, and Peters anomaly type 2 with cataract and iris coloboma in the left eye but no systemic issues. These findings were compared to published reports of PXDN-related ocular diseases upon comprehensive review of prior literature. RESULTS In both affected sisters, genome sequencing identified two novel heterozygous variants in trans in the PXDN gene: c.1569_1570insT, predicting p.(Thr524TyrfsTer53), and c.3206 C > A, predicting p.(Ala1069Asp), respectively. No other potentially diagnostic variants were identified in any other genes. CONCLUSIONS This report on two novel compound heterozygous variants in the PXDN gene associated with previously unreported clinical manifestations further expands the genotypic and phenotypic spectrum associated with this gene. Our finding of distinctive clinical phenotypes associated with identical compound heterozygous PXDN variants in monozygotic twins emphasizes the significant clinical variability that can occur, suggesting a potential role for stochastic developmental and/or epigenetic factors in the ultimate pathophysiologic pathway.
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Affiliation(s)
- Angela Y Zhu
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Ophthalmology and Visual Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto and Hospital for Sick Children, Toronto, Ontario, Canada.,Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
| | - Cheryl Cytrynbaum
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.,Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Rosanna Weksberg
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto and Hospital for Sick Children, Toronto, Ontario, Canada.,Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ronald D Cohn
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto and Hospital for Sick Children, Toronto, Ontario, Canada.,Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
| | - Asim Ali
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Ophthalmology and Visual Sciences, University of Toronto, Toronto, Ontario, Canada
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Ling C, Zhang D, Zhang J, Sun H, Du Q, Li X. Updates on the molecular genetics of primary congenital glaucoma (Review). Exp Ther Med 2020; 20:968-977. [PMID: 32742340 PMCID: PMC7388405 DOI: 10.3892/etm.2020.8767] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/01/2020] [Indexed: 12/14/2022] Open
Abstract
Primary congenital glaucoma (PCG) is one of the primary causes of blindness in children and is characterized by congenital trabecular meshwork and anterior chamber angle dysplasia. While being a rare condition, PCG severely impairs the quality of life of affected patients. However, the pathogenesis of PCG remains to be fully elucidated. It has previously been indicated that genetic factors serve a critical role in the pathogenesis of PCG, although patients with PCG exhibit significant genetic heterogeneity. Mutations in the cytochrome P450 family 1 subfamily B member 1 gene have been implicated in PCG and further genes that have been reported to be involved in PCG are myocilin, forkhead box C1, collagen type I α1 chain and latent transforming growth factor β binding protein 2. The present review aims to provide an up to date understanding of the genes associated with PCG and the use of molecular technologies in the identification of such genes and mutations. This may pave the way for the development of preventative methods, early diagnosis and improved therapeutic strategies in PCG.
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Affiliation(s)
- Chen Ling
- Sichuan Provincial Key Laboratory for Genetic Disease, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610072, P.R. China
| | - Dingding Zhang
- Sichuan Provincial Key Laboratory for Genetic Disease, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610072, P.R. China
| | - Jing Zhang
- Department of Thoracic Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Huanxin Sun
- Department of Immunology, North Sichuan Medical College, Nanchong, Sichuan 637100, P.R. China
| | - Qiu Du
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 610072, P.R. China
| | - Xuefei Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 610072, P.R. China
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Rauf B, Irum B, Khan SY, Kabir F, Naeem MA, Riazuddin S, Ayyagari R, Riazuddin SA. Novel mutations in LTBP2 identified in familial cases of primary congenital glaucoma. Mol Vis 2020; 26:14-25. [PMID: 32165823 PMCID: PMC7043638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 02/21/2020] [Indexed: 11/05/2022] Open
Abstract
Purpose Primary congenital glaucoma (PCG) is a genetically heterogeneous disorder caused by developmental defects in the anterior chamber and trabecular meshwork. This disease is an important cause of childhood blindness. In this study, we aim to identify the genetic determinants of PCG in three consanguineous families of Pakistani descent. Methods Affected members of all three families underwent detailed ophthalmological examination including slit-lamp biomicroscopy. Blood samples were collected from affected and healthy members of all three families, and genomic DNA was extracted. Linkage analysis was performed for the known or reported loci of PCG to localize the disease interval, and logarithm of odds (LOD) scores were calculated. All protein-coding exons of the candidate gene, latent transforming growth factor-beta binding protein 2 (LTBP2), were bidirectionally sequenced to identify the disease-causing mutation. Results Short tandem repeat (STR) marker-based linkage analysis localized the critical interval to chromosome 14q with a maximum two-point LOD score of 2.86 (PKGL076), 2.8 (PKGL015), and 2.92 (PKGL042). Bidirectional Sanger sequencing of LTBP2 revealed three novel pathogenic variants, i.e., c.3028G>A (p.Asp1010Asn), c.3427delC (p.Gln1143Argfs*35), and c.5270G>A (p.Cys1757Tyr) in PKGL076, PKGL015, and PKGL042, respectively. All three mutations segregated with the disease phenotype in their respective families and were absent in 200 ethnically matched normal chromosomes. Conclusions We identified three novel mutations, p.D1010N, p.Q1143Rfs*35, and p.C1757Y, in LTBP2 responsible for PCG.
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Affiliation(s)
- Bushra Rauf
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Bushra Irum
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shahid Y. Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - Radha Ayyagari
- Shiley Eye Institute, University of California San Diego, La Jolla, CA
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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16
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Novel PXDN biallelic variants in patients with microphthalmia and anterior segment dysgenesis. J Hum Genet 2020; 65:487-491. [PMID: 32015378 DOI: 10.1038/s10038-020-0726-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 01/08/2020] [Accepted: 01/11/2020] [Indexed: 02/06/2023]
Abstract
Microphthalmia, anophthalmia, and anterior segment dysgenesis are severe ocular developmental defects. There is a wide genetic heterogeneity leading to these ocular malformations. By using whole genome, exome and targeted sequencing in patients with ocular developmental anomalies, six biallelic pathogenic variants (including five novel variants) were identified in the PXDN gene in four families with microphthalmia and anterior segment dysgenesis. Only 11 different mutations (11 families) have been described in this gene to date. The phenotype of these patients is variable in severity, ranging from cataract and developmental glaucoma to complex microphthalmia. Interestingly, two unrelated patients of our series presented with an ocular phenotype including aniridia and microspherophakia. However, despite various phenotypic presentations and types of mutations, no genotype-phenotype correlation could be made. Thus, this work improves our knowledge of the recessive phenotype associated with biallelic variants in this gene and highlights the importance of screening PXDN in patients with anterior segment dysgenesis with or without microphthalmia.
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17
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Afzal R, Firasat S, Kaul H, Ahmed B, Siddiqui SN, Zafar SN, Shahzadi M, Afshan K. Mutational analysis of the CYP1B1 gene in Pakistani primary congenital glaucoma patients: Identification of four known and a novel causative variant at the 3' splice acceptor site of intron 2. Congenit Anom (Kyoto) 2019; 59:152-161. [PMID: 30270463 DOI: 10.1111/cga.12312] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/25/2018] [Accepted: 09/25/2018] [Indexed: 01/06/2023]
Abstract
Primary congenital glaucoma (PCG) causes blindness in early age. It has an autosomal recessive pattern of inheritance, hence is more prevalent in populations with frequent consanguineous marriages that occur in the Pakistani population. Mutations in the CYP1B1 gene are commonly associated with PCG. The aim of the present study was to identify genetic mutations in the CYP1B1 gene in PCG cases belonging to 38 Pakistani families. DNA was extracted using blood samples collected from all enrolled patients, their available unaffected family members and controls. Direct sequencing of the CYP1B1 gene revealed a novel 3' splice acceptor site causative variant segregating in an autosomal recessive manner in a large consanguineous family with four PCG-affected individuals. The novel variant was not detected in 93 ethnically matched controls. Furthermore, four already reported mutations, including p.G61E, p.R355X, p.R368H, and p.R390H were also detected in patients belonging to nine different families. All identified causative variants were evaluated by computational programs, that is, SIFT, PolyPhen-2, and MutationTaster. Pathogenicity of the novel splice site variant identified in this study was analyzed by Human Splicing Finder and MaxEntScan. Ten out of 38 families with PCG had the disease due to CYP1B1 mutations, suggesting CYP1B1 was contributing to PCG in these Pakistani patients. Identification of this novel 3' splice acceptor site variant in intron 2 is the first report for the CYP1B1 gene contributing to genetic heterogeneity of disease.
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Affiliation(s)
- Rabia Afzal
- Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sabika Firasat
- Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Haiba Kaul
- Genetics Division, Department of Livestock Production, University of Veterinary and Animal Sciences, Pattoki, Pakistan
| | - Bashir Ahmed
- Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sorath N Siddiqui
- Department of Pediatric Ophthalmology and Strabismus, Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan
| | - Saemah N Zafar
- Department of Pediatric Ophthalmology and Strabismus, Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan
| | - Misbah Shahzadi
- Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Kiran Afshan
- Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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18
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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.
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Morlino S, Alesi V, Calì F, Lepri FR, Secinaro A, Grammatico P, Novelli A, Drago F, Castori M, Baban A. LTBP2-related "Marfan-like" phenotype in two Roma/Gypsy subjects with the LTBP2 homozygous p.R299X variant. Am J Med Genet A 2018; 179:104-112. [PMID: 30565850 DOI: 10.1002/ajmg.a.10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/23/2018] [Accepted: 10/29/2018] [Indexed: 11/06/2022]
Abstract
Recessive variants in LTBP2 are associated with eye-restricted phenotypes including (a) primary congenital glaucoma and (b) microspherophakia/megalocornea and ectopia lentis with/without secondary glaucoma. Nosology of LTBP2 pathology in humans is apparently in contrast with the consolidated evidence of a wide expression of this gene in the developing embryo. Accordingly, in previously published patients with LTBP2-related eye disease, additional extraocular findings have been occasionally reported and include, among others, high-arched palate, tall stature, and variable cardiac involvement. Anyway, no emphasis was put on such systemic manifestations. Here, we report two unrelated Roma/Gypsy patients first ascertained for a multisystem disorder mainly characterized by primary congenital glaucoma, complex congenital heart defect, tall stature, long fingers, skin striae and dystrophic scarring, and resembling Marfan syndrome. Heart involvement was severe with polyvalvular heart dysplasia in one, and transposition of great arteries, thoracic arterial tortuosity, polyvalvular heart dysplasia, and neo-aortic root dilatation in the other. Both patients were homozygous for the recurrent c.895C>T[p.(R299X)] variant, typically found in individuals of Roma/Gypsy descent with an eye-restricted phenotype. Our findings point out LTBP2 as responsible of a systemic phenotype coherent with the community of syndromes related to anomalies in genes involved in the TGFβ-pathway. Among these disorders, LTBP2-related systemic disease emerges as a distinct condition with expanding prognostic implications and autosomal recessive inheritance.
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Affiliation(s)
- Silvia Morlino
- Laboratory of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Rome, Italy
| | - Viola Alesi
- Laboratory of Medical Genetics, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Federica Calì
- Pediatric Cardiology and Arrhythmology Unit, Department of Pediatric Cardiology and Cardiac Surgery, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Francesca Romana Lepri
- Laboratory of Medical Genetics, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Aurelio Secinaro
- Division of Radiology, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Paola Grammatico
- Laboratory of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Fabrizio Drago
- Pediatric Cardiology and Arrhythmology Unit, Department of Pediatric Cardiology and Cardiac Surgery, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Marco Castori
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (Foggia), Italy
| | - Anwar Baban
- Pediatric Cardiology and Arrhythmology Unit, Department of Pediatric Cardiology and Cardiac Surgery, IRCCS-Bambino Gesù Children Hospital and Research Institute, Rome, Italy
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Alías L, Crespi J, González-Quereda L, Téllez J, Martínez E, Bernal S, Gallano MP. Next-generation sequencing reveals a new mutation in the LTBP2 gene associated with microspherophakia in a Spanish family. BMC MEDICAL GENETICS 2018; 19:77. [PMID: 29751740 PMCID: PMC5948732 DOI: 10.1186/s12881-018-0590-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/22/2018] [Indexed: 01/12/2023]
Abstract
Background Microspherophakia is a rare autosomal recessive eye disorder characterized by small spherical lens. It may present as an isolated finding or in association with other ocular and/or systemic disorders. This clinical and genetic heterogeneity requires the study of large genes (ADAMTSL4, FBN1, LTBP2, ADAMTSL-10 and ADAMTSL17). The purpose of the present study is to identify the genetic cause of this pathology in a consanguineous Spanish family. Methods A clinical exome sequencing experiment was executed by the TruSight One® Sequencing Panel (TSO) from Illumina©. Sanger sequencing was used to validate the NGS results. Results Only the insertion of an adenine in exon 36 of the LTBP2 gene (c.5439_5440insA) was associated with pathogenicity. This new mutation was validated by Sanger sequencing and segregation analysis was also performed. Haplotype analyses using the polymorphic markers D14S1025, D14S43 and D14S999 close to the LTBP2 gene indicated identity by descent in this family. Conclusion We describe the first case of a microspherophakia phenotype associated with a novel homozygous mutation in the LTBP2 gene in a consanguineous Caucasian family by means of NGS technology.
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Affiliation(s)
- Laura Alías
- Department Genetics, Hospital de la Santa Creu i Sant Pau, Pare Claret, 167, 08025, Barcelona, Spain. .,CIBERER (U705), Barcelona, Spain.
| | - Jaume Crespi
- Department Ophthalmology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Lidia González-Quereda
- Department Genetics, Hospital de la Santa Creu i Sant Pau, Pare Claret, 167, 08025, Barcelona, Spain.,CIBERER (U705), Barcelona, Spain
| | - Jesús Téllez
- Department Ophthalmology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Elisabeth Martínez
- Department Genetics, Hospital de la Santa Creu i Sant Pau, Pare Claret, 167, 08025, Barcelona, Spain
| | - Sara Bernal
- Department Genetics, Hospital de la Santa Creu i Sant Pau, Pare Claret, 167, 08025, Barcelona, Spain
| | - Ma Pia Gallano
- Department Genetics, Hospital de la Santa Creu i Sant Pau, Pare Claret, 167, 08025, Barcelona, Spain.,CIBERER (U705), Barcelona, Spain
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Detection of mutations in MYOC, OPTN, NTF4, WDR36 and CYP1B1 in Chinese juvenile onset open-angle glaucoma using exome sequencing. Sci Rep 2018. [PMID: 29540704 PMCID: PMC5852028 DOI: 10.1038/s41598-018-22337-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Juvenile onset open-angle glaucoma (JOAG) affects patients before 40 years of age, causing high intraocular pressure and severe optic nerve damage. To expand the mutation spectrum of the causative genes in JOAG, with a view to identify novel disease-causing mutations, we investigated MYOC, OPTN, NTF4, WDR36 and CYP1B1 in a cohort of 67 unrelated Chinese JOAG patients. Whole exome sequencing was used to identify possible pathogenic mutations, which were further excluded in normal controls. After sequencing and the use of a database pipeline, as well as predictive assessment filtering, we identified a total of six mutations in three genes, MYOC, OPTN and CYP1B1. Among them, 2 heterozygous mutations in MYOC (c. 1109C > T, p. (P370L); c. 1150G > C, p. (D384H)), 2 heterozygous mutations in OPTN (c. 985A > G, p.(R329G); c. 1481T > G, p. (L494W)) and 2 homozygous mutations in CYP1B1 (c. 1412T > G, p.(I471S); c. 1169G > A, p.(R390H)) were identified as potentially causative mutations. No mutation was detected in NTF4 or WDR36. Our results enrich the mutation spectra and frequencies of MYOC, OPTN and CYP1B1 in JOAG among the Chinese population. Further studies are needed to address the pathogenicity of each of the mutations detected in this study.
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Sitole BN, Mavri-Damelin D. Peroxidasin is regulated by the epithelial-mesenchymal transition master transcription factor Snai1. Gene 2018; 646:195-202. [DOI: 10.1016/j.gene.2018.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/01/2017] [Accepted: 01/02/2018] [Indexed: 12/12/2022]
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Gupta S, Chatterjee S, Mukherjee A, Mutsuddi M. Whole exome sequencing: Uncovering causal genetic variants for ocular diseases. Exp Eye Res 2017; 164:139-150. [PMID: 28844620 DOI: 10.1016/j.exer.2017.08.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 01/23/2023]
Abstract
Identification of causal genetic defects for human diseases took a significant leap when the first generation DNA sequencing technologies enabled biologists extract sequence-based genetic information from living beings. However, these sequencing methods had unavoidable constraints of throughput, scalability, rapidity, and resolution. In this direction, next-generation sequencing (NGS) since the time of its advent has revolutionized the process of gene discovery for both monogenic and multifactorial genetic diseases. Among several variations of NGS, whole exome sequencing (WES) has emerged as a smart strategy that enables identification of disease causing variants present within the coding region of the human genome. The current review focuses primarily on the application of WES in identification of causal variants for ocular diseases. WES has successfully revealed pathogenic variants in a variety of ocular diseases such as retinal degenerations, refractive errors, lens diseases, corneal dystrophies, and developmental ocular defects. It has demonstrated immense potential for molecular diagnosis of genetic ocular diseases. WES has been extensively used in Mendelian and complex cases, familial and sporadic cases, simplex and multiplex cases, and syndromic and non-syndromic cases of ocular diseases. Although many such ocular diseases have been investigated using WES, reports indicate that it has been employed overwhelmingly for heterogeneous retinal degenerations. WES, within a short period of time, has proved to be a cost-effective and promising approach for understanding the genetic basis of ocular diseases.
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Affiliation(s)
- Shashank Gupta
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Souradip Chatterjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Ashim Mukherjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Mousumi Mutsuddi
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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