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Shen T, Qiu X, Lin X, Lin J, Li X, Chen Q, Pan L, Wang Z, Shen H, Zhang Q, Yan J. Missense mutation in the PAX6 gene can cause a complex mild variable phenotype predominated by concomitant strabismus. Ophthalmic Genet 2021; 43:88-96. [PMID: 34344282 DOI: 10.1080/13816810.2021.1961283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE We aimed to reveal the underlying genetic defect in a multigenerational Chinese family with autosomal dominant concomitant strabismus complicated by multiple ocular developmental abnormalities. METHODS Comprehensive ophthalmic examinations were performed in 14 patients and 24 healthy family members. Whole exome sequencing was performed, and Sanger sequencing was used to confirm the probable mutation in all the family members. RESULTS Concomitant strabismus was the predominant phenotype in the affected family members, although the patients also exhibited variable phenotypes, including nystagmus, mild iris abnormalities, myopia, cataract, and coloboma. An R208W mutation in PAX6 was identified as the pathogenic mutation in the affected family members. CONCLUSIONS We recommend considering PAX6 as a candidate gene in the diagnostic screen for familial concomitant strabismus in order to avoid missed diagnosis of the mild ocular abnormalities. Careful examinations of mild ocular phenotypes are necessary for an accurate diagnosis of varied ocular abnormalities in the families with the PAX6 mutation, and proper diagnosis can facilitate genetic and clinical counseling for affected patients.
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Affiliation(s)
- Tao Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xuan Qiu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoming Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiuling Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qiwen Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Liuqing Pan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhonghao Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Huangxuan Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jianhua Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Matsushita I, Morita H, Kondo H. Autosomal dominant foveal hypoplasia without visible macular abnormalities and PAX6 mutations. Jpn J Ophthalmol 2020; 64:635-641. [PMID: 32857266 DOI: 10.1007/s10384-020-00766-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 07/16/2020] [Indexed: 12/30/2022]
Abstract
PURPOSE Autosomal dominant foveal hypoplasia (FVH1) is a rare disorder associated with mutations in the PAX6 gene. As an isolated disease entity, FVH1 does not include ocular disorders such as aniridia, microphthalmia, albinism, and achromatopsia. However, it only includes isolated foveal hypoplasia and foveal hypoplasia with presenile cataract. The purpose of this report is to present our findings in four patients from two families with FVH1 without visible ophthalmic macular abnormalities. STUDY DESIGN A review of the medical records of two families with FVH1 and genetic confirmation of mutations in the PAX6 gene. METHODS Fundus photographs, optical coherence tomographic (OCT) and OCT angiographic (OCTA) images, and slit-lamp anterior segment findings were determined. The type of mutation of the PAX6 gene was determined. RESULTS A 3-year-old girl (Patient 1) had signs and symptoms of an impairment in the development of vision without other retinal abnormalities OU. OCT images showed a shallow foveal pit, and OCTA showed the absence of the foveal avascular zone. The second patient (Patient 2) was a 6-year-old girl with unilateral mild cataract and shallow foveal pits OU. Similar shallow foveal pits were found in her asymptomatic mother (Patient 3) and maternal grandfather (Patient 4). Although the iris and posterior fundus were normal, all patients with FVH1 had goniodysgenesis. Genetic testing of the PAX6 gene revealed that Patient 1 had a novel heterozygous mutation (p.Asn365Lys) as a de novo mutation, and Patients 2, 3 and 4 had a novel heterozygous mutation (p.Pro20Ser). CONCLUSIONS Heterozygous mutations in the PAX6 gene can cause FVH1 with nearly normal appearing macula. FVH1 is difficult to diagnose, but detailed observations of the foveal structure and vasculature, and detecting the presence of goniodysgenesis can be helpful in identifying patients with FVH1.
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Affiliation(s)
- Itsuka Matsushita
- Department of Ophthalmology, University of Occupational and Environmental Health, Japan, 1-1, Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, Japan
| | - Hirofumi Morita
- Department of Ophthalmology, University of Occupational and Environmental Health, Japan, 1-1, Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, Japan
| | - Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health, Japan, 1-1, Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, Japan.
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Williamson KA, Hall HN, Owen LJ, Livesey BJ, Hanson IM, Adams GGW, Bodek S, Calvas P, Castle B, Clarke M, Deng AT, Edery P, Fisher R, Gillessen-Kaesbach G, Heon E, Hurst J, Josifova D, Lorenz B, McKee S, Meire F, Moore AT, Parker M, Reiff CM, Self J, Tobias ES, Verheij JBGM, Willems M, Williams D, van Heyningen V, Marsh JA, FitzPatrick DR. Recurrent heterozygous PAX6 missense variants cause severe bilateral microphthalmia via predictable effects on DNA-protein interaction. Genet Med 2020; 22:598-609. [PMID: 31700164 PMCID: PMC7056646 DOI: 10.1038/s41436-019-0685-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Most classical aniridia is caused by PAX6 haploinsufficiency. PAX6 missense variants can be hypomorphic or mimic haploinsufficiency. We hypothesized that missense variants also cause previously undescribed disease by altering the affinity and/or specificity of PAX6 genomic interactions. METHODS We screened PAX6 in 372 individuals with bilateral microphthalmia, anophthalmia, or coloboma (MAC) from the Medical Research Council Human Genetics Unit eye malformation cohort (HGUeye) and reviewed data from the Deciphering Developmental Disorders study. We performed cluster analysis on PAX6-associated ocular phenotypes by variant type and molecular modeling of the structural impact of 86 different PAX6 causative missense variants. RESULTS Eight different PAX6 missense variants were identified in 17 individuals (15 families) with MAC, accounting for 4% (15/372) of our cohort. Seven altered the paired domain (p.[Arg26Gln]x1, p.[Gly36Val]x1, p.[Arg38Trp]x2, p.[Arg38Gln]x1, p.[Gly51Arg]x2, p.[Ser54Arg]x2, p.[Asn124Lys]x5) and one the homeodomain (p.[Asn260Tyr]x1). p.Ser54Arg and p.Asn124Lys were exclusively associated with severe bilateral microphthalmia. MAC-associated variants were predicted to alter but not ablate DNA interaction, consistent with the electrophoretic mobility shifts observed using mutant paired domains with well-characterized PAX6-binding sites. We found no strong evidence for novel PAX6-associated extraocular disease. CONCLUSION Altering the affinity and specificity of PAX6-binding genome-wide provides a plausible mechanism for the worse-than-null effects of MAC-associated missense variants.
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Affiliation(s)
- Kathleen A Williamson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - H Nikki Hall
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Liusaidh J Owen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Benjamin J Livesey
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Isabel M Hanson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | | | - Simon Bodek
- Department of Clinical Genetics, St Michael's Hospital, Southwell Street, Bristol, UK
| | - Patrick Calvas
- CHU Toulouse, Service de Génétique Médicale, Hôpital Purpan, Toulouse, France
| | - Bruce Castle
- Peninsula Clinical Genetics, Royal Devon and Exeter Hospitals (Heavitree), Exeter, UK
| | - Michael Clarke
- Newcastle Eye Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Alexander T Deng
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Patrick Edery
- Hospices Civils de Lyon, Genetic Department and National HHT Reference Center, Femme-Mère-Enfants Hospital, Bron, France
| | - Richard Fisher
- Teeside Genetics Unit, The James Cook University Hospital, Middlesbrough, UK
| | | | - Elise Heon
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, ON, Canada
| | - Jane Hurst
- Department of Clinical Genetics, Great Ormond Street Hospital for Children, London, UK
| | - Dragana Josifova
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Shane McKee
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, UK
| | - Francoise Meire
- Department of Ophthalmology, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium
| | | | - Michael Parker
- Department of Clinical Genetics, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Charlotte M Reiff
- Department of Ophthalmology, University of Freiburg, Freiburg, Germany
| | - Jay Self
- University Hospital Southampton, Southampton, UK
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Edward S Tobias
- Academic Medical Genetics and Pathology, University of Glasgow, Queen Elizabeth University Hospital, Glasgow, UK
| | - Joke B G M Verheij
- Department of Genetics, University of Groningen, University Medical Center, Groningen, The Netherlands
| | | | - Denise Williams
- Clinical Genetics Unit, Birmingham Women's Hospital, Birmingham, UK
| | - Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
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