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Landsend ECS, Lagali N, Utheim TP. Congenital aniridia - A comprehensive review of clinical features and therapeutic approaches. Surv Ophthalmol 2021; 66:1031-1050. [PMID: 33675823 DOI: 10.1016/j.survophthal.2021.02.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/16/2021] [Accepted: 02/23/2021] [Indexed: 12/13/2022]
Abstract
Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, leading to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease.
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Affiliation(s)
| | - Neil Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tor P Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
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Tian W, Zhu XR, Qiao CY, Ma YN, Yang FY, Zhou Z, Feng JP, Sun R, Xie RR, Lu J, Cao X, Zhou JB, Yang JK. Heterozygous PAX6 mutations may lead to hyper-proinsulinaemia and glucose intolerance: A case-control study in families with congenital aniridia. Diabet Med 2021; 38:e14456. [PMID: 33169869 DOI: 10.1111/dme.14456] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022]
Abstract
AIM PAX6 is a transcription factor involved in embryonic development of many organs, including the eyes and the pancreas. Mutations of PAX6 gene is the main cause of a rare disease, congenital aniridia (CA). This case-control study aims to investigate the effects of PAX6 mutations on glucose metabolism and insulin secretion in families with CA. METHODS In all, 21 families with CA were screened by Sanger sequencing. Patients with PAX6 mutations and CA (cases) and age-matched healthy family members (controls) were enrolled. Oral glucose tolerance test (OGTT) was performed to detect diabetes or impaired glucose tolerance (IGT). Insulin and proinsulin secretion were evaluated. RESULTS Among 21 CA families, heterozygous PAX6 mutations were detected in five families. Among cases (n = 10) from the five families, two were diagnosed with newly identified diabetes and another two were diagnosed with IGT. Among controls (n = 12), two had IGT. The levels of haemoglobin A1c were 36 ± 4 mmol/mol (5.57 ± 0.46%) and 32 ± 5 mmol/L (5.21 ± 0.54%) in the cases and the controls, respectively (p = 0.049). More importantly, levels of proinsulin in the cases were significantly higher than that of the controls, despite similar levels of total insulin. The areas under the curve of proinsulin in the cases (6425 ± 4390) were significantly higher than that of the controls (3709 ± 1769) (p = 0.032). CONCLUSION PAX6 may participate in the production of proinsulin to insulin and heterozygous PAX6 mutations may be associated with glucose metabolism in CA patients.
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Affiliation(s)
- Wei Tian
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiao-Rong Zhu
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
| | - Chun-Yan Qiao
- Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ying-Nan Ma
- Beijing Institute of Ophthalmology, Beijing, China
| | - Fang-Yuan Yang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
| | - Zhen Zhou
- Department of Mathematics, School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Jian-Ping Feng
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ran Sun
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Rong-Rong Xie
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jing Lu
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
| | - Xi Cao
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
| | - Jian-Bo Zhou
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
| | - Jin-Kui Yang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Diabetes Institute, Beijing, China
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Macdonald GC, Hesselson SE, Chan JY, Jenkins AB, Laybutt DR, Hesselson D, Campbell LV. Deletion distal to the PAX6 coding region reveals a novel basis for familial cosegregation of aniridia and diabetes mellitus. Diabetes Res Clin Pract 2019; 148:64-71. [PMID: 30572005 DOI: 10.1016/j.diabres.2018.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/22/2018] [Accepted: 12/12/2018] [Indexed: 11/17/2022]
Abstract
AIMS Analyze cosegregation of aniridia and diabetes to identify genetic criteria for detection and early treatment of diabetes-susceptible aniridia patients. METHODS We assessed a two-generation family: three individuals with aniridia, two previously diagnosed as type 2 diabetes. One individual with aniridia, with unknown diabetes status, was evaluated by oral glucose tolerance test. Genetic analysis of aniridia-associated genes was performed on all available family members. Candidate genes were functionally tested by gene silencing in MIN6 pancreatic β-cells. RESULTS A 25 year old male with aniridia had a diabetic oral glucose tolerance test despite a normal fasting blood glucose. A 484-630 kb deletion ∼120 kb distal to PAIRED BOX 6 (PAX6) showed dominant cosegregation with aniridia and diabetes in all affected family members. The deleted region contains regulatory elements for PAX6 expression and four additional coding regions. Knockdown of two of the deleted genes (Dnajc24 or Immp1l) with Pax6 impaired glucose-stimulated insulin secretion. CONCLUSIONS We demonstrate dominant cosegregation of diabetes and aniridia with a deletion distal to PAX6, which is clinically distinct from the mild glucose intolerance previously reported with PAX6 coding mutations. Asymptomatic aniridia individuals appear at risk of diabetes (and its complications) and could benefit from earlier diagnosis and treatment.
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Affiliation(s)
- Gemma C Macdonald
- Diabetes Centre, St Vincent's Hospital, Sydney, New South Wales, Australia.
| | - Stephanie E Hesselson
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Jeng Yie Chan
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, NSW, Australia; St Vincent's Clinical School, UNSW Sydney, NSW, Australia
| | - Arthur B Jenkins
- School of Medicine, University of Wollongong, Wollongong, Australia
| | - D Ross Laybutt
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, NSW, Australia; St Vincent's Clinical School, UNSW Sydney, NSW, Australia
| | - Daniel Hesselson
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst, Australia; St Vincent's Clinical School, UNSW Sydney, Australia.
| | - Lesley V Campbell
- Diabetes Centre, St Vincent's Hospital, Sydney, New South Wales, Australia; Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst, Australia; St Vincent's Clinical School, UNSW Sydney, Australia; Department of Endocrinology, St Vincent's Hospital, Sydney, Australia
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