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Bursle C, Riney K, Stringer J, Moore D, Gole G, Kearns LS, Mackey DA, Coman D. Leber Hereditary Optic Neuropathy and Longitudinally Extensive Transverse Myelitis. JIMD Rep 2017; 42:53-60. [PMID: 29249004 PMCID: PMC6226398 DOI: 10.1007/8904_2017_79] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/02/2017] [Accepted: 11/27/2017] [Indexed: 12/23/2022] Open
Abstract
Leber Hereditary Optic Neuropathy is an inherited optic neuropathy caused by mitochondrial DNA point mutations leading to sudden, painless loss of vision. We report a case of an 8-year-old boy presenting with a radiological phenotype of longitudinally extensive transverse myelitis on a background of severe visual impairment secondary to Leber Hereditary Optic Neuropathy (LHON). He was found to have dual mitochondrial DNA mutations at 14484 (MTND6 gene) and 4160 (MTND1 gene) in a family with a severe form of LHON characterised by not only an unusually high penetrance of optic neuropathy, but also severe extra-ocular neurological complications. The m.14484T>C mutation is a common LHON mutation, but the m.4160T>C mutation is to our knowledge not reported outside this family and appears to drive the neurological manifestations. To our knowledge there have been no previous reports of spinal cord lesions in children with LHON.
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Affiliation(s)
- C Bursle
- Neurosciences Unit, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - K Riney
- Neurosciences Unit, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - J Stringer
- Neurosciences Unit, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - D Moore
- Department of Paediatrics, The Wesley Hospital, Brisbane, QLD, Australia
| | - G Gole
- Department of Ophthalmology, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - L S Kearns
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Parkville, VIC, Australia
| | - D A Mackey
- Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, WA, Australia
- School of Medicine, Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - D Coman
- Neurosciences Unit, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia.
- UnitingCare Clinical School, The Wesley Hospital, Brisbane, QLD, Australia.
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
- Department of Paediatrics, The Wesley Hospital, Brisbane, QLD, Australia.
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Forward H, Yazar S, Hewitt AW, Khan J, Mountain JA, Pesudovs K, McKnight CM, Tan AX, Pennell CE, Mackey DA, Newnham JP. Multiple prenatal ultrasound scans and ocular development: 20-year follow-up of a randomized controlled trial. Ultrasound Obstet Gynecol 2014; 44:166-170. [PMID: 24789332 DOI: 10.1002/uog.13399] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 04/14/2014] [Accepted: 04/20/2014] [Indexed: 06/03/2023]
Abstract
OBJECTIVES Through comprehensive ophthalmic examination of adult offspring we sought to determine the impact of multiple prenatal ultrasound scans on ocular development. METHODS 2743 pregnant women recruited to the Western Australian Pregnancy (Raine) Cohort study during 1989-1991 were randomized to receive at King Edward Memorial Hospital, Western Australia either multiple prenatal ultrasound scans and Doppler flow studies (intensive group) or a single ultrasound scan at 18 weeks' gestation. Neonatal birth weight of the offspring and other physical measurements were collected prospectively. At age 20 years, participants underwent a comprehensive ophthalmic examination including measurement of ocular biometry and visual acuity. RESULTS Complete data were available for 1134 adult offspring participants. The mothers of 563 of these had been randomized to receive multiple prenatal ultrasound scans. The mean age of participants at follow-up was 20.0 years. There was no statistically significant difference between the two groups with regard to ocular biometric or visual outcomes, except for slightly higher intraocular pressure identified in individuals exposed to multiple ultrasound scans (P = 0.034). Although infants in the intensive-ultrasound arm were more likely to have birth weights in the lower quartiles, this was not reflected in adult eye development. Axial length, lens thickness, corneal curvature and thickness and optic cup to disc ratio (a risk factor for glaucomatous optic neuropathy) were not significantly influenced by the more frequent ultrasound protocol. CONCLUSIONS Prior to this study, there was a paucity of safety data for ultrasound with regard to eye development. We found that frequent in-utero exposure to ultrasound, including B-mode imaging and the use of spectral Doppler mode from 18 weeks' gestation, had no significant impact on visual outcomes or ocular biometry.
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Affiliation(s)
- H Forward
- Centre for Ophthalmology and Vision Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Perth, Australia
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Ng WY, Pasutto F, Bardakjian TM, Wilson MJ, Watson G, Schneider A, Mackey DA, Grigg JR, Zenker M, Jamieson RV. A puzzle over several decades: eye anomalies with FRAS1 and STRA6 mutations in the same family. Clin Genet 2012; 83:162-8. [PMID: 22283518 DOI: 10.1111/j.1399-0004.2012.01851.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Fraser syndrome (FS) and microphthalmia syndromic 9 (MCOPS9) are autosomal recessive conditions with distinct, and some overlapping features affecting the ocular, respiratory and cardiac systems. Mutations in FRAS1 and FREM2 occur in FS, and mutations in STRA6 occur in MCOPS9. We report two sibships, in the same family, where four deceased offspring had ocular, respiratory and cardiac abnormalities. Two sibs with microphthalmia had syndactyly and laryngeal stenosis, suggesting a clinical diagnosis of FS. Our results indicate that they were compound heterozygotes for novel FRAS1 mutations, p.Cys729Phe and p.Leu3813Pro. The other two sibs, first cousins to the first sib pair, had anophthalmia, lung hypoplasia and cardiac anomalies, suggesting a retrospective diagnosis of MCOPS9. Our results indicate compound heterozygous STRA6 mutations, a novel frameshift leading to p.Tyr18* and a p.Thr644Met mutation. The one surviving individual from these sibships is heterozygous for the p.Tyr18*STRA6 mutation and has bilateral ocular colobomata and microphthalmia. This work emphasises the need for careful phenotypic characterisation to determine genes for assessment in ocular syndromic conditions. It also indicates that heterozygous STRA6 mutations may rarely contribute to microphthalmia and coloboma.
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Affiliation(s)
- W Y Ng
- Eye Genetics Research Group, Children's Medical Research Institute, The Children's Hospital at Westmead, Save Sight Institute, Sydney, Australia
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Pavone P, Mackey DA, Parano E, Barbagallo M, Praticò AD, Trifiletti RR. Blepharoptosis in children: our experience at the light of literature. Clin Ter 2010; 161:241-243. [PMID: 20589354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
AIMS We herein report a 5 years experience of management and care of children presenting blepharoptosis at the light of the literature regarding this uncommon pathology. This report aims to display the most common causes of blepharoptosis and its possible treatment. PATIENTS AND METHODS Clinical and epidemiological data collected from our institution, over a fi ve year period, on 60 patients, 37 males and 23 females with a mean age of 5.4 years (range 0.6 to 15.6 years) affected by blepharoptosis were analyzed. RESULTS Ptosis was unilateral in 39/60 patients (65%) and bilateral in 21/60 (35%). The causes of ptosis were myogenic (40%), and neurogenic (35%), most commonly congenital. Among the neurogenic ptosis, the most frequent causes were PTOS type 1 and Marcus-Gunn syndrome. All the cases of acquired neurogenic ptosis were associated with paralysis of the oculomotor nerve. Ptosis plus was found in 23.3% of the patients, mechanical origin was present in 1.7% of patients. Family history was positive in the 10% of the patients. CONCLUSIONS Our series reflect the range of ptosis of the general pediatric population. This study highlights the high degree of heterogeneity in patients with ptosis; only with an accurate analysis of the family and patient history and of the clinical features it is possible to perform an accurate diagnosis, finding the genetic causes and an adequate treatment.
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Affiliation(s)
- P Pavone
- Department of Pediatrics, University of Catania, Italy
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Abstract
AIMS To estimate the heritability of intraocular pressure (IOP) by performing a classical twin study and to determine whether the use of different instruments influences calculation of eye IOP heritability. METHODS Twin pairs were recruited to participate from the TwinsUK Adult Twin Registry at St. Thomas' Hospital London. IOP was measured using Goldmann applanation tonometry (GAT). A subset of twins also had their IOP measured using the Ocular Response Analyser (ORA; Reichert, Buffalo, NY) and the Dynamic Contour Tonometer (DCT, Pascal; Swiss Microtechnology AG, Port, Switzerland). We compared the covariance of IOP within monozygotic (MZ) and dizygotic (DZ) pairs using genetic modelling techniques to determine the relative contribution of genes and environment to the variation in IOP seen in this population. RESULTS Data for 422 twin pairs (211 MZ; 211 DZ) were analysed. The mean IOP for GAT was 15.4 (SD 2.7) mm Hg (range: 8.7-26.2 mm Hg). The MZ correlations were significantly higher than DZ for IOP measured by GAT, DCT and ORA (correlation coefficients: GAT: 0.57:0.39, DCT: 0.62:0.36, Goldmann-correlated ORA (IOPg) 0.73:0.47, for MZ:DZ twins, respectively). Modelling suggested heritability for GAT IOP of 0.62, with individual environmental factors accounting for 0.38 of the variation. CONCLUSION This study demonstrated that genetic effects are important in determining IOP in this twin population. IOP readings differed depending upon the instrument used, and this resulted in different heritability values; genetic factors explained 62%, 63% and 74% of the variation in IOP using GAT, DCT and ORA IOPg, respectively. Environmental factors determined the remainder of the variation.
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Affiliation(s)
- F Carbonaro
- Twin Research and Genetic Epidemiology Unit, King's College London School of Medicine, London, UK.
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Abstract
BACKGROUND/AIMS Autosomal dominant optic atrophy (ADOA) is a genetically heterogenous disease. However, a large proportion of this disease is accounted for by mutations in OPA1. The aim of this longitudinal study was to investigate disease progression in Australian ADOA patients with confirmed OPA1 mutations. METHODS Probands with characteristic clinical findings of ADOA were screened for OPA1 mutations, and relatives of identified mutation carriers were invited to participate. Disease progression was determined by sequential examination or using historical records over a mean of 9.6 (range 1-42) years. RESULTS OPA1 mutation carriers (n = 158) were identified in 11 ADOA pedigrees. Sixty-nine mutation carriers were available for longitudinal follow-up. Using the right eye as the default, best-corrected visual acuity (BCVAR) remained unchanged (defined as visual acuity at or within one line of original measurement) in 43 patients (62%). BCVAR worsened by 2 lines in 13 patients (19%). BCVAR deteriorated by more than 2 lines in six patients (9%). Ten per cent of patients had an improvement in visual acuity. Mean time to follow-up was 9.6 years with the mean visual acuity being 6/18 for both the initial and subsequent measurements. There was no statistical significance in the rate of BCVAR loss across different OPA1 mutations (p = 0.55). CONCLUSION OPA1-related ADOA generally progresses slowly and functional visual acuity is usually maintained. Longitudinal disease studies are important to enable appropriate counselling of patients. This study enables a better understanding of the natural history of ADOA.
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Affiliation(s)
- A C Cohn
- Centre for Eye Research Australia, University of Melbourne, Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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Ponsonby AL, Brown SA, Kearns LS, MacKinnon JR, Scotter LW, Cochrane JA, Mackey DA. The association between maternal smoking in pregnancy, other early life characteristics and childhood vision: the Twins Eye Study in Tasmania. Ophthalmic Epidemiol 2008; 14:351-9. [PMID: 18161608 DOI: 10.1080/01658100701486467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE To investigate the association between maternal smoking in pregnancy, early-life environment and childhood vision. METHODS Twin and triplet children enrolled in the Twins Eye Study in Tasmania underwent a comprehensive ophthalmic examination and their parents/guardians retrospectively answered a questionnaire regarding crawling, walking and other measures. A subset of these twins was also in the Tasmanian Infant Health Survey, which prospectively collected data on antenatal smoking, gestation, birth weight and other factors. RESULTS The mean age of the 346 individuals (172 multiple birth sets) at the time of examination was 9.25+/-2.4 years. Mean unaided visual acuity was 0.0 (6/6). The mean spherical equivalent was +0.87D, and decreased with increasing child age (p<0.01). A prospective analysis, accounting for birth set clustering and relevant confounders, showed increasing levels of maternal smoking in the third trimester was associated with poor stereoacuity on the Titmus test (worse (>) than 100'', p=0.05) and Lang test (p=0.001) and also with the presence of esotropia (p=0.02). These associations persisted after adjustment for infant postnatal smoke exposure at one month of age. Poor stereoacuity on Titmus stereo test circles was associated with late age of first crawling (RR=1.23 (1.06, 1.42) p=0.005 per month) and late age of first walking (RR 1.18 (1.05, 1.22) p=0.001 per month). CONCLUSIONS Antenatal smoking was independently associated with poor stereovision and the presence of esotropia. Poor stereoacuity may be associated with delayed age at first crawling or walking.
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Affiliation(s)
- A L Ponsonby
- Menzies Institute, University of Tasmania, Australia
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Dimasi DP, Hewitt AW, Straga T, Pater J, MacKinnon JR, Elder JE, Casey T, Mackey DA, Craig JE. Prevalence of CYP1B1 mutations in Australian patients with primary congenital glaucoma. Clin Genet 2007; 72:255-60. [PMID: 17718864 DOI: 10.1111/j.1399-0004.2007.00864.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Analysis of CYP1B1 in primary congenital glaucoma (PCG) patients from various ethnic populations indicates that allelic heterogeneity is high, and some mutations are population specific. No study has previously reported the rate or spectrum of CYP1B1 mutations in Australian PCG patients. The aim of this study is to determine the frequency of CYP1B1 mutations in our predominately Caucasian, Australian cohort of PCG cases. Thirty-seven probands were recruited from South-Eastern Australia, along with 100 normal control subjects. Genomic DNA was extracted and the coding regions of CYP1B1 analysed by direct sequencing. Sequence analysis identified 10 different CYP1B1 disease-causing variants in eight probands (21.6%). Five subjects were compound heterozygotes, two subjects heterozygous and one homozygous for CYP1B1 mutations. Three missense mutations are novel (D192Y, G329D, and P400S). None of the novel mutations identified were found in normal controls. One normal control subject was heterozygous for the previously reported CYP1B1 R368H mutation. Six previously described probable polymorphisms were also identified. Mutations in CYP1B1 account for approximately one in five PCG cases from Australia. Our data also supported the high degree of allelic heterogeneity seen in similar studies from other ethnic populations, thereby underscoring the fact that other PCG-related genes remain to be identified.
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Affiliation(s)
- D P Dimasi
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, Australia
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Craig JE, Hewitt AW, Dimasi DP, Howell N, Toomes C, Cohn AC, Mackey DA. The role of the Met98Lys optineurin variant in inherited optic nerve diseases. Br J Ophthalmol 2006; 90:1420-4. [PMID: 16885188 PMCID: PMC1857489 DOI: 10.1136/bjo.2006.099333] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To investigate the role of the common OPTN Met98Lys variant as a risk allele in open-angle glaucoma (OAG), autosomal dominant optic atrophy (ADOA) and Leber's hereditary optic neuropathy (LHON). METHODS The presence of the Met98Lys variant was determined in a total of 498 (128 with normal-tension glaucoma (NTG)) patients with OAG, 29 patients who had myocilin-related OAG, 101 patients from ADOA pedigrees, 157 patients from LHON pedigrees and 218 examined OAG age-matched normal controls. RESULTS 17 of 218 (7.8%) controls had the Met98Lys variant. 28 (5.6%) patients with OAG were Met98Lys positive. More Met98Lys carriers were found in the NTG group than in the high-tension glaucoma (HTG) group (p = 0.033). However, no significant difference was observed between the NTG and control cohorts (p = 0.609). Two MYOC mutation carriers were found to have the variant. The variant was found in 1 of 10 pedigrees with ADOA and in 8 of 35 pedigrees with LHON. CONCLUSION Data from this study do not support a strong role for the OPTN Met98Lys variant in glaucoma, ADOA or LHON. However, a weak association was observed of the variant with NTG compared with that with HTG. Meta-analysis of all published data on the variant and glaucoma confirmed that the association, although weak, is highly statistically significant in the cohort with glaucoma versus controls.
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Affiliation(s)
- J E Craig
- Department of Ophthalmology, Flinders University, Flinders Drive, Bedford Park, South Australia 5042, Australia.
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Dimasi DP, Hewitt AW, Green CM, Mackey DA, Craig JE. Lack of association of p53 polymorphisms and haplotypes in high and normal tension open angle glaucoma. J Med Genet 2006; 42:e55. [PMID: 16140998 PMCID: PMC1736135 DOI: 10.1136/jmg.2005.032458] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND The final common pathway for open angle glaucoma (OAG) is retinal ganglion cell apoptosis. Polymorphisms in p53, a major regulator of apoptosis, affect the efficiency of cell death induction. Association studies of p53 haplotypes and OAG have had conflicting results. OBJECTIVE To examine the association between p53 haplotypes and OAG in a larger white population than in previous reports, and extend the analysis to normal tension glaucoma. METHODS 345 unrelated people with OAG were recruited (283 subjects with high tension glaucoma and 62 with normal tension glaucoma) and compared with 178 age matched controls. Genomic DNA was analysed for the p53 codon 72 Arg/Pro polymorphism as well as for the presence or absence of a 16 bp intron 3 insertion. RESULTS In this white cohort no association was found between glaucoma (high or normal tension) and either sequence variant or haplotype. CONCLUSIONS The p53 codon 72 Arg/Pro polymorphism is not associated with age of onset or severity of glaucoma.
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Mimiwati Z, Mackey DA, Craig JE, Mackinnon JR, Rait JL, Liebelt JE, Ayala-Lugo R, Vollrath D, Richards JE. Nail-patella syndrome and its association with glaucoma: a review of eight families. Br J Ophthalmol 2006; 90:1505-9. [PMID: 16825280 PMCID: PMC1857543 DOI: 10.1136/bjo.2006.092619] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Nail-patella syndrome (NPS) is a rare autosomal dominant syndrome, characterised by dysplasia of the nails, patellae, elbows and iliac horns. Mutations in the LMX1B gene were found in four North American families in whom glaucoma cosegregated with NPS. AIMS To investigate the association of glaucoma with NPS in Australian families and to determine how common NPS is in Australia. METHODS One family with NPS and glaucoma was identified from the Glaucoma Inheritance Study in Tasmania. A further 18 index cases of NPS were identified from the genetics database for southeastern Australia. Eight of these pedigrees were available for comprehensive glaucoma examination on available family members. DNA was sequenced for mutations in LMX1B. RESULTS In total, 52 living cases of NPS were identified suggesting a minimum prevalence of at least 1 in 100 000. 32 subjects from eight NPS pedigrees (four familial and four sporadic cases) were examined. 14 subjects had NPS alone. 4 subjects had NPS and glaucoma or ocular hypertension. Five pedigrees with NPS had a reported family history of glaucoma, although some of these people with glaucoma did not have NPS. LMX1B mutations were identified in 5 of the 8 index cases-three sporadic and two familial. Two of the six (33%) participants over 40 years of age had developed glaucoma, showing increased risk of glaucoma in NPS. CONCLUSION Patients with NPS should be examined regularly for glaucoma. However, because the families with NPS are ascertained primarily from young probands or probands who are isolated cases, the exact level of risk is unclear.
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Affiliation(s)
- Z Mimiwati
- Department of Ophthalmology, Eye Research, University of Melbourne, Victoria 3002, Australia
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McKay JD, Patterson B, Craig JE, Russell-Eggitt IM, Wirth MG, Burdon KP, Hewitt AW, Cohn AC, Kerdraon Y, Mackey DA. The telomere of human chromosome 1p contains at least two independent autosomal dominant congenital cataract genes. Br J Ophthalmol 2005; 89:831-4. [PMID: 15965161 PMCID: PMC1772710 DOI: 10.1136/bjo.2004.058495] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS Multiple genetic causes of congenital cataract have been identified, both as a component of syndromes and in families that present with isolated congenital cataract. Linkage analysis was used to map the genetic locus in a six generation Australian family presenting with total congenital cataract. METHODS Microsatellite markers located across all known autosomal dominant congenital cataract loci were genotyped in all recruited family members of the Tasmanian family. Both two point and multipoint linkage analysis were used to assess each locus under an autosomal dominant model. RESULTS Significant linkage was detected at the telomere of the p arm of chromosome 1, with a maximum two point LOD of 4.21 at marker D1S507, a maximum multipoint exact LOD of 5.44, and an estimated location score of 5.61 at marker D1S507. Haplotype analysis places the gene inside a critical region between D1S228 and D1S199, a distance of approximately 6 megabases. The candidate gene PAX7 residing within the critical interval was excluded by direct sequencing in affected individuals. CONCLUSION This is the third report of congenital cataract linkage to 1ptel. The critical region as defined by the shared haplotype in this family is clearly centromeric from the Volkmann cataract locus identified through study of a Danish family, indicating that two genes causing autosomal dominant congenital cataract map to the telomeric region of chromosome 1p.
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Affiliation(s)
- J D McKay
- Genome analysis team, International Agency for Research on Cancer, Lyons, France
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Burdon KP, Wirth MG, Mackey DA, Russell-Eggitt IM, Craig JE, Elder JE, Dickinson JL, Sale MM. A novel mutation in the Connexin 46 gene causes autosomal dominant congenital cataract with incomplete penetrance. J Med Genet 2004; 41:e106. [PMID: 15286166 PMCID: PMC1735867 DOI: 10.1136/jmg.2004.018333] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- K P Burdon
- Menzies Centre for Population Health Research, University of Tasmania, Hobart, Australia
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Yu-Wai-Man P, Howell N, Mackey DA, Nørby S, Rosenberg T, Turnbull DM, Chinnery PF. Mitochondrial DNA haplogroup distribution within Leber hereditary optic neuropathy pedigrees. J Med Genet 2004; 41:e41. [PMID: 15060117 PMCID: PMC1735729 DOI: 10.1136/jmg.2003.011247] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Burdon KP, Wirth MG, Mackey DA, Russell-Eggitt IM, Craig JE, Elder JE, Dickinson JL, Sale MM. Investigation of crystallin genes in familial cataract, and report of two disease associated mutations. Br J Ophthalmol 2004; 88:79-83. [PMID: 14693780 PMCID: PMC1771940 DOI: 10.1136/bjo.88.1.79] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS Mutations of seven crystallin genes have been shown to cause familial cataract. The authors aimed to identify disease causing crystallin mutations in paediatric cataract families from south eastern Australia. METHODS 38 families with autosomal dominant or recessive paediatric cataract were examined. Three large families were studied by linkage analysis. Candidate genes at regions providing significant LOD scores were sequenced. Single stranded conformational polymorphism (SSCP) analysis was used to screen five crystallin genes in the probands, followed by direct sequencing of observed electrophoretic shifts. Mutations predicted to affect the coding sequence were subsequently investigated in the entire pedigree. RESULTS A LOD score of 3.72 was obtained at the gamma-crystallin locus in one pedigree. Sequencing revealed a P23T mutation of CRYGD, found to segregate with disease. A splice site mutation at the first base of intron 3 of the CRYBA1/A3 gene segregating with disease was identified by SSCP in another large family. Five polymorphisms were also detected. CONCLUSIONS Although mutations in the five crystallin genes comprehensively screened in this study account for 38% of paediatric cataract mutations in the literature, only two causative mutations were detected in 38 pedigrees, suggesting that crystallin mutations are a relatively rare cause of the cataract phenotype in this population.
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Affiliation(s)
- K P Burdon
- Menzies Centre for Population Health Research, University of Tasmania, Hobart, Australia
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Affiliation(s)
- D A Mackey
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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Affiliation(s)
- W T Ng
- St Vincent's Hospital, Fitzroy, Victoria, Australia
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Mackey DA, Fingert JH, Luzhansky JZ, McCluskey PJ, Howell N, Hall AJH, Pierce AB, Hoy JF. Leber's hereditary optic neuropathy triggered by antiretroviral therapy for human immunodeficiency virus. Eye (Lond) 2003; 17:312-7. [PMID: 12724691 DOI: 10.1038/sj.eye.6700362] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To describe the clinical features of two cases of Leber's hereditary optic neuropathy (LHON) precipitated by antiretroviral treatment for human immunodeficiency virus (HIV) infection. METHODS Two cases of LHON (from an expected four new cases a year throughout Australia) were identified in men on treatment for HIV infection. RESULTS Two HIV-infected men were receiving combination antiretroviral therapy that included nucleoside analogues. Both patients carried the 14 484 mitochondrial DNA mutation and were distantly related (seventh cousins). Although both men presented with sequential visual loss typical of LHON and one had a known close relative affected by LHON, the correct diagnosis was delayed in both cases. The final visual outcome was profoundly reduced in both instances and cessation of antiretroviral therapy did not result in recovery of vision in one patient. CONCLUSION Patients with a family history of LHON who require antiretroviral treatment should be warned of the high risk of severe visual loss. The underlying mechanism of antiretroviral side effects may help characterize the other trigger factors for LHON.
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Affiliation(s)
- D A Mackey
- Department of Ophthalmology, Centre for Eye Research, Australia Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne, Victoria 3002, Australia.
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Howell N, Smejkal CB, Mackey DA, Chinnery PF, Turnbull DM, Herrnstadt C. The pedigree rate of sequence divergence in the human mitochondrial genome: there is a difference between phylogenetic and pedigree rates. Am J Hum Genet 2003; 72:659-70. [PMID: 12571803 PMCID: PMC1180241 DOI: 10.1086/368264] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Accepted: 12/13/2002] [Indexed: 11/03/2022] Open
Abstract
We have extended our previous analysis of the pedigree rate of control-region divergence in the human mitochondrial genome. One new germline mutation in the mitochondrial DNA (mtDNA) control region was detected among 185 transmission events (generations) from five Leber hereditary optic neuropathy (LHON) pedigrees. Pooling the LHON pedigree analyses yields a control-region divergence rate of 1.0 mutation/bp/10(6) years (Myr). When the results from eight published studies that used a similar approach were pooled with the LHON pedigree studies, totaling >2,600 transmission events, a pedigree divergence rate of 0.95 mutations/bp/Myr for the control region was obtained with a 99.5% confidence interval of 0.53-1.57. Taken together, the cumulative results support the original conclusion that the pedigree divergence rate for the control region is approximately 10-fold higher than that obtained with phylogenetic analyses. There is no evidence that any one factor explains this discrepancy, and the possible roles of mutational hotspots (rate heterogeneity), selection, and random genetic drift and the limitations of phylogenetic approaches to deal with high levels of homoplasy are discussed. In addition, we have extended our pedigree analysis of divergence in the mtDNA coding region. Finally, divergence of complete mtDNA sequences was analyzed in two tissues, white blood cells and skeletal muscle, from each of 17 individuals. In three of these individuals, there were four instances in which an mtDNA mutation was found in one tissue but not in the other. These results are discussed in terms of the occurrence of somatic mtDNA mutations.
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Abstract
Retinopathy of prematurity (ROP) has been recognised as an important cause of childhood visual impairment and blindness since the 1940s when improved facilities and treatment increased the survival rate of premature infants. Although its incidence and severity have been decreasing in developed countries over the past two decades, both are increasing in developing nations. ROP is consequently targeted as an important but avoidable disease. This review provides an updated summary and discussion of much of the work that has been produced through population, animal, cell culture, and genetic research. The authors examine the prevalence, risk factors, and possible causes of the disease with a particular focus on genetic studies. They conclude that while significant reductions in the disease have occurred in developed countries, further research is required to fully understand and prevent the disease. In the meantime, development and implementation of appropriate screening and treatment strategies will be critical in reducing blindness in developing countries.
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Affiliation(s)
- C M Wheatley
- Discipline of Biochemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
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Marchbank NJ, Craig JE, Leek JP, Toohey M, Churchill AJ, Markham AF, Mackey DA, Toomes C, Inglehearn CF. Deletion of the OPA1 gene in a dominant optic atrophy family: evidence that haploinsufficiency is the cause of disease. J Med Genet 2002; 39:e47. [PMID: 12161614 PMCID: PMC1735190 DOI: 10.1136/jmg.39.8.e47] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- N J Marchbank
- Molecular Medicine Unit, University of Leeds, Clinical Sciences Building, St James's University Hospital, Leeds LS9 7TF, UK
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Wirth MG, Russell-Eggitt IM, Craig JE, Elder JE, Mackey DA. Aetiology of congenital and paediatric cataract in an Australian population. Br J Ophthalmol 2002; 86:782-6. [PMID: 12084750 PMCID: PMC1771196 DOI: 10.1136/bjo.86.7.782] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2002] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM Paediatric cataract is a major cause of childhood blindness. Several genes associated with congenital and paediatric cataracts have been identified. The aim was to determine the incidence of cataract in a population, the proportion of hereditary cataracts, the mode of inheritance, and the clinical presentation. METHODS The Royal Children's Hospital and the Royal Victorian Eye and Ear Hospital have a referral base for almost all paediatric patients with cataracts in south eastern Australia. The database contains cases seen over the past 25 years. The medical histories of these patients were reviewed. RESULTS 421 patients with paediatric cataract were identified, which gives an estimated incidence of 2.2 per 10,000 births. Of the 342 affected individuals with a negative family history, 50% were diagnosed during the first year of life, and 56/342 (16%) were associated with a recognised systemic disease or syndrome. Unilateral cataract was identified in 178/342 (52%) of sporadic cases. 79 children (from 54 nuclear families) had a positive family history. Of these 54 families, 45 were recruited for clinical examination and DNA collection. Ten nuclear families were subsequently found to be related, resulting in four larger pedigrees. Thus, 39 families have been studied. The mode of inheritance was autosomal dominant in 30 families, X linked in four, autosomal recessive in two, and uncertain in three. In total, 178 affected family members were examined; of these 8% presented with unilateral cataracts and 43% were diagnosed within the first year of life. CONCLUSIONS In the paediatric cataract population examined, approximately half of the patients were diagnosed in the first year of life. More than 18% had a positive family history of cataracts. Of patients with hereditary cataracts 8% presented with unilateral involvement. Identification of the genes that cause paediatric and congenital cataract should help clarify the aetiology of some sporadic and unilateral cataracts.
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Affiliation(s)
- M G Wirth
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Australia
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Abstract
Retinopathy of prematurity (ROP) has been recognised as an important cause of childhood visual impairment and blindness since the 1940s when improved facilities and treatment increased the survival rate of premature infants. Although its incidence and severity have been decreasing in developed countries over the past two decades, both are increasing in developing nations. ROP is consequently targeted as an important but avoidable disease. This review provides an updated summary and discussion of much of the work that has been produced through population, animal, cell culture, and genetic research. The authors examine the prevalence, risk factors, and possible causes of the disease with a particular focus on genetic studies. They conclude that while significant reductions in the disease have occurred in developed countries, further research is required to fully understand and prevent the disease. In the meantime, development and implementation of appropriate screening and treatment strategies will be critical in reducing blindness in developing countries.
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Affiliation(s)
- C M Wheatley
- Discipline of Biochemistry, University of Tasmania, Hobart, Tasmania, Australia
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Mitchell AE, Elder JE, Mackey DA, Waters KD, Ashley DM. Visual improvement despite radiologically stable disease after treatment with carboplatin in children with progressive low-grade optic/thalamic gliomas. J Pediatr Hematol Oncol 2001; 23:572-7. [PMID: 11902299 DOI: 10.1097/00043426-200112000-00004] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The purpose of this study was to examine the clinical and radiologic response to carboplatin by children with progressive optic/thalamic gliomas. PATIENTS AND METHODS Between July 1997 and July 1999, 12 consecutive children were treated with monthly carboplatin for progressive optic/thalamic gliomas. RESULTS Five children have completed 12 cycles of carboplatin and five children are currently receiving treatment. Two children had progressive disease noted both clinically and radiologically. Nine children have stable radiologic disease and one child has had a partial radiologic response to chemotherapy. Eight children have had regular visual assessments. Four children (three with stable radiology and one with a partial radiologic response) have had improvement in their vision. Three children with radiologically stable disease have had no change in vision. One child has had deterioration in vision despite radiologically stable disease. CONCLUSIONS The results suggest that the clinical response of optic/thalamic gliomas to carboplatin, as measured by visual acuity and visual fields, may be better than predicted by radiologic assessment. These data suggest that a prospective clinical study is warranted of the role of carboplatin in children with progressive optic/thalamic gliomas and visual impairment.
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Affiliation(s)
- A E Mitchell
- Department of Hematology and Oncology, Royal Children's Hospital, Parkville, Victoria, Australia
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MacKinnon JR, Challis DR, Mackey DA. Is it not in my records, doctor? Clin Exp Ophthalmol 2001; 29:440-1. [PMID: 11778820 DOI: 10.1046/j.1442-9071.2001.d01-35.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Craig JE, Baird PN, Healey DL, McNaught AI, McCartney PJ, Rait JL, Dickinson JL, Roe L, Fingert JH, Stone EM, Mackey DA. Evidence for genetic heterogeneity within eight glaucoma families, with the GLC1A Gln368STOP mutation being an important phenotypic modifier. Ophthalmology 2001; 108:1607-20. [PMID: 11535458 DOI: 10.1016/s0161-6420(01)00654-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To investigate the phenotype and age-related penetrance of primary open-angle glaucoma (POAG) in Australian families with the most common Myocilin mutation (Gln368STOP). DESIGN Cross-sectional genetic study. PARTICIPANTS Eight pedigrees carrying the Gln368STOP mutation were ascertained from 1730 consecutive cases of POAG in the Glaucoma Inheritance Study in Tasmania. METHODS Index cases and available family members were examined for signs of glaucoma, and the presence of the GLC1A Gln368STOP mutation was ascertained by single-strand conformation polymorphism analysis and subsequent direct sequencing. RESULTS From the eight pedigrees, 29 Gln368STOP mutation-carrying individuals with either ocular hypertension (OHT) or POAG were found, with a mean age at diagnosis of 52.4 +/- 12.9 years and a mean peak intraocular pressure (IOP) of 28.4 +/- 4.7 mmHg. A further 11 mutation carriers older than 40 years have been studied, who as yet show no signs of OHT or POAG. Within the 8 pedigrees, a further 31 individuals with OHT or POAG were identified who did not carry the Gln368STOP mutation. For these individuals the mean age at diagnosis was higher (62.3 +/- 13.7 years, P < 0.01), and the mean peak IOP was lower (25.4 +/- 6.4 mmHg, P = 0.01). For Gln368STOP carriers, age-related penetrance for OHT or POAG was 72% at age 40 years and 82% at age 65 years. A positive family history of POAG was present in all index cases. Five of the eight pedigrees had a positive family history on both maternal and paternal sides. Seven of the eight pedigrees had one or more individuals with POAG who did not carry the mutation. Eight of the 29 Gln368STOP carriers with OHT or POAG had undergone trabeculectomy. CONCLUSIONS The GLC1A Gln368STOP mutation is associated with POAG, which in the pedigrees studied is of a younger age of onset and higher peak IOP than non-mutation glaucoma cases. In addition, Gln368STOP mutation glaucoma cases were more likely to have undergone glaucoma drainage surgery. We have not observed simple autosomal dominant inheritance patterns for POAG in these pedigrees. Other factors, as yet uncharacterized, are involved in expression of the POAG phenotype in Gln368STOP pedigrees.
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Affiliation(s)
- J E Craig
- Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
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McKie AB, McHale JC, Keen TJ, Tarttelin EE, Goliath R, van Lith-Verhoeven JJ, Greenberg J, Ramesar RS, Hoyng CB, Cremers FP, Mackey DA, Bhattacharya SS, Bird AC, Markham AF, Inglehearn CF. Mutations in the pre-mRNA splicing factor gene PRPC8 in autosomal dominant retinitis pigmentosa (RP13). Hum Mol Genet 2001; 10:1555-62. [PMID: 11468273 DOI: 10.1093/hmg/10.15.1555] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Retinitis pigmentosa (RP) is a genetically heterogeneous disorder characterized by progressive degeneration of the peripheral retina leading to night blindness and loss of visual fields. With an incidence of approximately 1 in 4000, RP can be inherited in X-linked, autosomal dominant or autosomal recessive modes. The RP13 locus for autosomal dominant RP (adRP) was placed on chromosome 17p13.3 by linkage mapping in a large South African adRP family. Using a positional cloning and candidate gene strategy, we have identified seven different missense mutations in the splicing factor gene PRPC8 in adRP families. Three of the mutations cosegregate within three RP13 linked families including the original large South African pedigree, and four additional mutations have been identified in other unrelated adRP families. The seven mutations are clustered within a 14 codon stretch within the last exon of this large 7 kb transcript. The altered amino acid residues at the C-terminus exhibit a high degree of conservation across species as diverse as humans, Arabidopsis and trypanosome, suggesting that some functional significance is associated with this part of the protein. These mutations in this ubiquitous and highly conserved splicing factor offer compelling evidence for a novel pathway to retinal degeneration.
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Affiliation(s)
- A B McKie
- Molecular Medicine Unit, University of Leeds, Clinical Sciences Building, St James' University Hospital, Leeds LS9 7TF, UK
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Toomes C, Marchbank NJ, Mackey DA, Craig JE, Newbury-Ecob RA, Bennett CP, Vize CJ, Desai SP, Black GC, Patel N, Teimory M, Markham AF, Inglehearn CF, Churchill AJ. Spectrum, frequency and penetrance of OPA1 mutations in dominant optic atrophy. Hum Mol Genet 2001; 10:1369-78. [PMID: 11440989 DOI: 10.1093/hmg/10.13.1369] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dominant optic atrophy (DOA) is the commonest form of inherited optic neuropathy. Although heterogeneous, a major locus has been mapped to chromosome 3q28 and the gene responsible, OPA1, was recently identified. We therefore screened a panel of 35 DOA patients for mutations in OPA1. This revealed 14 novel mutations and a further three known mutations, which together accounted for 20 of the 35 families (57%) included in this study. This more than doubles the number of OPA1 mutations reported in the literature, bringing the total to 25. These are predominantly null mutations generating truncated proteins, strongly suggesting that the mechanism underlying DOA is haploinsufficiency. The mutations are largely family-specific, although a common 4 bp deletion in exon 27 (eight different families) and missense mutations in exons 8 (two families) and 9 (two families) have been identified. Haplotype analysis of individuals with the exon 27 2708del(TTAG) mutation suggests that this is a mutation hotspot and not an ancient mutation, thus excluding a major founder effect at the OPA1 locus. The mutation screening in this study also identified a number of asymptomatic individuals with OPA1 mutations. A re-calculation of the penetrance of this disorder within two of our families indicates figures as low as 43 and 62% associated with the 2708del(TTAG) mutation. If haploinsufficiency is the mechanism underlying DOA it is unlikely that this figure will be mutation-specific, indicating that the penetrance in DOA is much lower than the 98% reported previously. To investigate whether Leber's hereditary optic neuropathy (LHON) could be caused by mutations in OPA1 we also screened a panel of 28 LHON patients who tested negatively for the three major LHON mutations. No mutations were identified in any LHON patients, indicating that DOA and LHON are genetically distinct.
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Affiliation(s)
- C Toomes
- Molecular Medicine Unit, Clinical Sciences Building, University of Leeds, St James's University Hospital, Leeds, LS9 7TF, UK
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Baird PN, Dickinson J, Craig JE, Mackey DA. The Taa1 restriction enzyme provides a simple means to identify the Q368STOP mutation of the myocilin gene in primary open angle glaucoma. Am J Ophthalmol 2001; 131:510-1. [PMID: 11292420 DOI: 10.1016/s0002-9394(00)00812-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE To identify a rapid and reliable method to detect the Glutamine 368 STOP (Q368STOP) disease-predisposing allele of the myocilin gene associated with adult onset, primary, open-angle glaucoma. METHODS Individuals with the Q368STOP mutation of the myocilin gene were identified from a cohort of primary open-angle glaucoma patients from Tasmania and subjected to Taa1 restriction digestion. RESULTS In the Tasmanian family presented, screening with the Taa1 restriction enzyme successfully confirmed identification of all individuals with the Q368STOP mutation. CONCLUSIONS The use of the Taa1 restriction enzyme offers a relatively simple, rapid, and reproducible technique that could be applied to detect the Q368STOP mutation of the myocilin gene.
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Affiliation(s)
- P N Baird
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.
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Abstract
DNA samples are the fundamental research substrate in genetics. Although methodology and cost-effectiveness in molecular biology have improved dramatically, collecting biological samples and extracting DNA continue to be expensive and time-consuming steps of genetic research. This article reviews the issues surrounding the choice of biological samples for methods of DNA extraction as well as the storage and transport of biological and DNA samples for genetic studies.
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Affiliation(s)
- J L Dickinson
- Menzies Centre for Population Health Research, University of Tasmania, Hobart, Tasmania, Australia
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Fingert JH, Clark AF, Craig JE, Alward WL, Snibson GR, McLaughlin M, Tuttle L, Mackey DA, Sheffield VC, Stone EM. Evaluation of the myocilin (MYOC) glaucoma gene in monkey and human steroid-induced ocular hypertension. Invest Ophthalmol Vis Sci 2001; 42:145-52. [PMID: 11133859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
PURPOSE Glucocorticoid-induced ocular hypertension (the steroid response) may result in optic nerve damage that very closely mimics the pathologic course of primary open angle glaucoma (POAG). In addition, patients with glaucoma and their relatives are much more likely to exhibit the steroid response than unaffected individuals, suggesting a potential link between the steroid response and POAG. Recently, the expression of a gene (MYOC) in the trabecular meshwork was shown to be steroid-induced. MYOC variations thought to be disease-causing also were found in 3% to 5% of POAG cases. The purpose of this study was to determine whether some variations in MYOC might be involved in steroid-induced ocular hypertension. METHODS Seventy human steroid responders and 114 control subjects were screened for variations in the coding sequence and promoter of MYOC. Also, topical doses of dexamethasone (DEX) were administered to cynomolgus monkeys to determine their steroid responsiveness, and the MYOC orthologue was cloned from the cynomolgus monkey. RESULTS Overall, 109 instances of 20 different sequence variations were identified in the human myocilin gene. However, only four of these (each observed in a single individual) met the study criteria for a possible phenotype-altering variation. Three of these were present in steroid responders and one in a control patient, a distribution that was not statistically significant (P: = 0.3). In addition, the allele frequency of a closely flanking marker was compared between the steroid responders and the control subjects, and no evidence for linkage disequilibrium was observed. Reproducible and reversible ocular hypertension was induced in approximately 40% of the monkeys treated with DEX, similar to that seen in man. Ten monkeys were screened for MYOC mutations with single-strand conformation polymorphism (SSCP) analysis. Overall, 37 instances of 13 different sequence variations were observed. Four of these changes met the study criteria for a possible phenotype-altering variation, and these were equally distributed between responder and nonresponder monkeys. CONCLUSIONS This study identified no statistically significant evidence for a link between MYOC mutations and steroid-induced ocular hypertension.
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Affiliation(s)
- J H Fingert
- Departments of Ophthalmology and. Pediatrics, and. The Howard Hughes Medical Institute, The University of Iowa College of Medicine, Iowa City, IA 52242, USA
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McNaught AI, Allen JG, Healey DL, McCartney PJ, Coote MA, Wong TL, Craig JE, Green CM, Rait JL, Mackey DA. Accuracy and implications of a reported family history of glaucoma: experience from the Glaucoma Inheritance Study in Tasmania. Arch Ophthalmol 2000; 118:900-4. [PMID: 10900101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
OBJECTIVES To ascertain the prevalence of previously undiagnosed primary open-angle glaucoma (POAG) within 5 large POAG pedigrees and to evaluate the reliability of a reported family history of glaucoma within these pedigrees. METHODS The Glaucoma Inheritance Study in Tasmania (GIST) identified several large adult POAG pedigrees. Intraocular pressure (IOP), optic disc stereophotography, and automated perimetry were performed on all adult pedigree members. Participants were classified as normal (IOP <22 mm Hg and normal optic disc and field); glaucoma suspect (normal field, but an IOP >/=22 mm Hg and/or suspicious optic disc); or POAG (field defect and glaucomatous optic disc). Some individuals with POAG had been previously diagnosed by their local ophthalmologist; others were diagnosed as a result of the GIST project. Family members with a prior diagnosis of POAG were asked to report if they were aware of any relatives with POAG. This reported family history was then directly compared with the actual pedigree (before the diagnosis of new cases) to calculate agreement. MAIN OUTCOME MEASURE The rate of glaucoma in pedigrees and percentage of previously diagnosed glaucoma cases who were aware of the positive family history of POAG. RESULTS Four hundred forty-two subjects (mean age, 54 years [range, 13-97 years]) from 5 pedigrees were examined: 316 subjects (71%) were normal, 47 (11%) were previously diagnosed with POAG, and 8 (2%) were previously diagnosed glaucoma suspects; 30 cases (7%) of POAG and 41 suspects (9%) were newly diagnosed as a direct result of the GIST examination. Of the 47 previously diagnosed POAG cases, 41 were questioned about their prior knowledge of any family history and 11 (27%) were unaware of their family history of POAG. CONCLUSIONS Examination of all adult subjects from POAG families yields new cases. Even in large POAG pedigrees, 27% of previously diagnosed POAG patients were unaware of their positive family history. These findings suggest that a higher percentage of adult POAG may be inherited than hitherto reported. Arch Ophthalmol. 2000;118:900-904
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Affiliation(s)
- A I McNaught
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, East Melbourne, 3002 Victoria, Australia
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Abstract
PURPOSE Vigabatrin (Sabril), a drug that blocks GABA transaminase, has been used in the treatment of epilepsy since 1989. There have been reports of irreversible constriction of the visual field in adult patients related to vigabatrin (VGB) therapy, resulting in reduced VGB usage in adults. Although used as a second or third line agent in adults, in children it is often considered as a first line treatment for several subgroups of seizures in spite of there being no way, in the majority of cases, to monitor visual fields. Some of these children have a pre-existing visual field defect as part of their primary disorder. We aimed to identify whether visual field loss due to VGB was occurring in our hospital. METHODS We have studied the results of ophthalmic examination in 14 children on VGB at Great Ormond Street Hospital who were able to perform Goldmann visual fields. RESULTS Ten of the 14 patients had constriction of their visual fields attributed to VGB. In addition there were 2 patients with suspicious visual field defects thought to be due to VGB. There was pre-existing visual pathway damage in 4 cases and in 2 of these optic disc pallor increased in association with constricted visual fields. However, the optic discs were normal in 7 patients in spite of visual field constriction. Visual acuity was generally normal in spite of gross visual field constriction. CONCLUSIONS We believe that VGB should be used with great caution where there is pre-existing visual pathway damage. In other cases the benefits should be considered in relation to the risks, which include irreversible visual field damage. At present visual fields can only be monitored by perimetry, which is often not possible in children with epilepsy.
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Abstract
OBJECTIVE Until recently, inhaled corticosteroids were not considered to cause elevated intraocular pressure (IOP), although topical and oral corticosteroids have been shown to do so in susceptible individuals. The authors aimed to (1) identify whether an association existed between inhaled corticosteroid use and elevated IOP or open-angle glaucoma and (2) determine whether this effect may have a genetic basis. DESIGN Cross-sectional, population-based study of 3654 persons 49 to 97 years of age attending the Blue Mountains Eye Study, near Sydney, Australia. METHODS A series of questions assessed use of inhaled and other corticosteroids as well as family history of glaucoma. Elevated IOP was assessed using applanation tonometry. Diagnosis of glaucoma was based on automated perimetry defects and optic disc signs but without reference to IOP. MAIN OUTCOME MEASURE Statistical analysis of associations between inhaled corticosteroid use and elevated IOP or glaucoma, by family history, adjusting for other risk factors. RESULTS Open-angle glaucoma was diagnosed in 108 subjects, and elevated IOP was found in 160 subjects. In persons with a glaucoma family history, there was a strong association between inhaled corticosteroid use and presence of either glaucoma or elevated IOP (odds ratio [OR], 2.6; 95% confidence interval, 1.2-5.8). The risk increased with higher doses (OR, 6.3; 95% CI, 1.0-38.6) for persons who used more than four puffs per day. These findings were not explained by concurrent use of oral or ocular corticosteroids. In persons without a family history of glaucoma, no association was found between use of inhaled corticosteroids and glaucoma or elevated IOP. CONCLUSIONS These findings suggest an association between ever use of inhaled corticosteroids and a finding of elevated IOP or glaucoma in subjects with a glaucoma family history. Patients being treated with inhaled corticosteroids need review by an ophthalmologist if they report a glaucoma family history.
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Affiliation(s)
- P Mitchell
- Department of Ophthalmology, University of Sydney, New South Wales, Australia.
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Stone EM, Lotery AJ, Munier FL, Héon E, Piguet B, Guymer RH, Vandenburgh K, Cousin P, Nishimura D, Swiderski RE, Silvestri G, Mackey DA, Hageman GS, Bird AC, Sheffield VC, Schorderet DF. A single EFEMP1 mutation associated with both Malattia Leventinese and Doyne honeycomb retinal dystrophy. Nat Genet 1999; 22:199-202. [PMID: 10369267 DOI: 10.1038/9722] [Citation(s) in RCA: 311] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Malattia Leventinese (ML) and Doyne honeycomb retinal dystrophy (DHRD) refer to two autosomal dominant diseases characterized by yellow-white deposits known as drusen that accumulate beneath the retinal pigment epithelium (RPE). Both loci were mapped to chromosome 2p16-21 (refs 5,6) and this genetic interval has been subsequently narrowed. The importance of these diseases is due in large part to their close phenotypic similarity to age-related macular degeneration (AMD), a disorder with a strong genetic component that accounts for approximately 50% of registered blindness in the Western world. Just as in ML and DHRD, the early hallmark of AMD is the presence of drusen. Here we use a combination of positional and candidate gene methods to identify a single non-conservative mutation (Arg345Trp) in the gene EFEMP1 (for EGF-containing fibrillin-like extracellular matrix protein 1) in all families studied. This change was not present in 477 control individuals or in 494 patients with age-related macular degeneration. Identification of this mutation may aid in the development of an animal model for drusen, as well as in the identification of other genes involved in human macular degeneration.
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Affiliation(s)
- E M Stone
- The Department of Ophthalmology, The University of Iowa College of Medicine, Iowa City, USA.
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Fingert JH, Héon E, Liebmann JM, Yamamoto T, Craig JE, Rait J, Kawase K, Hoh ST, Buys YM, Dickinson J, Hockey RR, Williams-Lyn D, Trope G, Kitazawa Y, Ritch R, Mackey DA, Alward WL, Sheffield VC, Stone EM. Analysis of myocilin mutations in 1703 glaucoma patients from five different populations. Hum Mol Genet 1999; 8:899-905. [PMID: 10196380 DOI: 10.1093/hmg/8.5.899] [Citation(s) in RCA: 318] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.
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Affiliation(s)
- J H Fingert
- Department of Ophthalmology, The University of Iowa College of Medicine, Iowa City, IA 52242, USA
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Abstract
The understanding of the genetic basis of the glaucomas has advanced rapidly. Mutations in the myocilin gene (previously known as TIGR) at the GLC1A locus on chromosome 1q21-q31 occur in a subset of patients with juvenile- and adult-onset primary open-angle glaucoma. Five other genetic localizations for primary open-angle glaucoma have now been reported. In patients with primary congenital glaucoma, mutations have been found in the CYP1B1 gene on chromosome 2p21. At least one other locus for primary congenital glaucoma is mapped. In the developmental glaucomas, mutations in the PITX2 gene on chromosome 4q25 have been associated with Rieger syndrome, iris hypoplasia, and iridogoniodysgenesis. A second locus for Rieger syndrome resides on chromosome 13q14. Mutations in the FKHL7 gene on chromosome 6p25 have been described in patients with Axenfeld-Rieger anomaly. A new ocular finding of glaucoma in pedigrees with the nailpatella syndrome has been described, and mutations in the LMX1B gene on chromosome 9q34 are now known to underlie nail-patella syndrome. Two loci for the pigment dispersion syndrome have been mapped. This paper provides an overview of recent literature, summarizes developments in glaucoma genetics, and addresses their potential relevance to the clinical management of glaucoma.
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Affiliation(s)
- J E Craig
- Centre for Eye Research Australia, University of Melbourne, Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
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Carden SM, Colville DJ, Davidson AJ, McKenzie IM, Mackey DA, McKenzie J, Elder JE. Adjunctive intra-operative local anaesthesia in paediatric strabismus surgery: a randomized controlled trial. Aust N Z J Ophthalmol 1998; 26:289-97. [PMID: 9843256 DOI: 10.1111/j.1442-9071.1998.tb01332.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The aim of the present study was to test the hypothesis that adjunctive local anaesthesia decreases postoperative pain, vomiting or length of stay in children having strabismus repair METHOD A prospective, randomized, triple-armed clinical trial involving a treatment comparison between topical amethocaine, sub-conjunctival bupivacaine and, as a placebo, topical normal saline was performed. All treatments were given at the end of surgery before emergence from the anaesthetic. RESULTS Overall, there was no statistically significant difference between outcome measures in the three trial groups. Using post hoc analysis there was a statistically significant difference between the groups receiving amethocaine and bupivacaine compared with the saline group in terms of the pain score at 120 min postoperatively. This difference has little clinical significance. CONCLUSIONS Neither topical amethocaine nor subconjunctival bupivacaine makes a clinically significant difference to postoperative pain, emesis or length of stay. Moderate dose paracetamol per rectum alone appears to be effective analgesia for strabismus surgery, although it probably masked any small adjunctive effect of the topical anaesthesia used in the present trial.
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Affiliation(s)
- S M Carden
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Victoria, Australia
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Alward WL, Fingert JH, Coote MA, Johnson AT, Lerner SF, Junqua D, Durcan FJ, McCartney PJ, Mackey DA, Sheffield VC, Stone EM. Clinical features associated with mutations in the chromosome 1 open-angle glaucoma gene (GLC1A). N Engl J Med 1998; 338:1022-7. [PMID: 9535666 DOI: 10.1056/nejm199804093381503] [Citation(s) in RCA: 265] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND A substantial proportion of cases of glaucoma have a genetic basis. Mutations causing glaucoma have been identified in the chromosome 1 open-angle glaucoma gene (GLC1A), which encodes a 57-kd protein known as myocilin. The normal role of this protein and the mechanism by which mutations cause glaucoma are not known. METHODS We screened 716 patients with primary open-angle glaucoma and 596 control subjects for sequence changes in the GLC1A gene. RESULTS We identified 16 sequence variations that met the criteria for a probable disease-causing mutation because they altered the predicted amino acid sequence and they were found in one or more patients with glaucoma, in less than 1 percent of the control subjects. These 16 mutations were found in 33 patients (4.6 percent). Six of the mutations were found in more than 1 subject (total, 99). Clinical features associated with these six mutations included an age at diagnosis ranging from 8 to 77 years and maximal recorded intraocular pressures ranging from 12 to 77 mm Hg. CONCLUSIONS A variety of mutations in the GLC1A gene are associated with glaucoma. The spectrum of disease can range from juvenile glaucoma to typical late-onset primary open-angle glaucoma.
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Affiliation(s)
- W L Alward
- Department of Ophthalmology, University of Iowa, Iowa City 52242, USA
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Stone EM, Fingert JH, Alward WL, Nguyen TD, Polansky JR, Sunden SL, Nishimura D, Clark AF, Nystuen A, Nichols BE, Mackey DA, Ritch R, Kalenak JW, Craven ER, Sheffield VC. Identification of a gene that causes primary open angle glaucoma. Science 1997; 275:668-70. [PMID: 9005853 DOI: 10.1126/science.275.5300.668] [Citation(s) in RCA: 840] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Glaucoma is a major cause of blindness and is characterized by progressive degeneration of the optic nerve and is usually associated with elevated intraocular pressure. Analyses of sequence tagged site (STS) content and haplotype sharing between families affected with chromosome 1q-linked open angle glaucoma (GLC1A) were used to prioritize candidate genes for mutation screening. A gene encoding a trabecular meshwork protein (TIGR) mapped to the narrowest disease interval by STS content and radiation hybrid mapping. Thirteen glaucoma patients were found to have one of three mutations in this gene (3.9 percent of the population studied). One of these mutations was also found in a control individual (0.2 percent). Identification of these mutations will aid in early diagnosis, which is essential for optimal application of existing therapies.
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Affiliation(s)
- E M Stone
- Department of Ophthalmology, University of Iowa College of Medicine, Iowa City, IA 52242, USA
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Sack J, Healey DL, de Graaf AP, Wilkinson RM, Wilkinson CH, Barbour JM, Coote MA, McCartney PJ, Rait JL, Cooper RL, Ring MA, Mackey DA. The problem of overlapping glaucoma families in the Glaucoma Inheritance Study in Tasmania (GIST). Ophthalmic Genet 1996; 17:209-14. [PMID: 9010872 DOI: 10.3109/13816819609057895] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The Glaucoma Inheritance Study in Tasmania (GIST) is a population survey of Australia's island state, Tasmania (population 450,000). Its aim is to find families with autosomal dominant, adult-onset, primary open angle glaucoma (POAG) suitable for genetic linkage analysis. POAG is relatively common, affecting around 3% of the Australian population. By finding the large families with POAG and identifying all the descendants in a captive population, it is possible that there may be overlap of different glaucoma pedigrees. Three of the first thirteen families in the study were composed of overlapping pedigrees. In one GIST family, GTas3, there has been intermarriage with other pedigrees with glaucoma on five occasions. The possibility of multiple genotypes was also reinforced by the inability to determine a single glaucoma phenotype in this family. When finding large families of POAG for linkage analysis, researchers must be aware of the risk of affected individuals inheriting their gene from the alternate parent. Thus, the alternate parents or their families must be examined, especially if the phenotype is atypical for the rest of the family.
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Affiliation(s)
- J Sack
- Department of Ophthalmology, University of Melbourne, Australia
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Coote MA, McCartney PJ, Wilkinson RM, Mackey DA. The 'GIST' score: ranking glaucoma for genetic studies. Glaucoma Inheritance Study of Tasmania. Ophthalmic Genet 1996; 17:199-208. [PMID: 9010871 DOI: 10.3109/13816819609057894] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The 'GIST' score was developed to facilitate linkage analysis of adult-onset primary open angle glaucoma (POAG) pedigrees in the Glaucoma Inheritance Study of Tasmania (GIST). Previous genetic linkage studies on juvenile open angle glaucoma pedigrees have relied upon an analysis of definitely affected individuals using the 'single best diagnosis' convention. Studies of adult-onset POAG have been complicated by limited numbers of unequivocally affected members identified even in very large pedigrees due to the later onset of the disease. Many members of the pedigree may have equivocal clinical features or are too young to show signs of the disease. The 'GIST score' is a numeric value between zero and one where zero is clinical certainty of absence of the disease and one is the definitive diagnosis of POAG. The score is developed by assigning relative weighting to key clinical features which results in a 'pedigee probability' of the diagnosis being present or absent in a member of a pedigree. Ranking of borderline and unaffected glaucoma subjects allows the laboratory more flexibility in the use of the members of the pedigree for linkage analysis. The score is not intended to have clinical usefulness in management of glaucoma.
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Affiliation(s)
- M A Coote
- Department of Ophthalmology, University of Melbourne, Australia
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Howell N, Kubacka I, Mackey DA. How rapidly does the human mitochondrial genome evolve? Am J Hum Genet 1996; 59:501-9. [PMID: 8751850 PMCID: PMC1914922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The results of an empirical nucleotide-sequencing approach indicate that the evolution of the human mitochondrial noncoding D-loop is both more rapid and more complex than is revealed by standard phylogenetic approaches. The nucleotide sequence of the D-loop region of the mitochondrial genome was determined for 45 members of a large matrilineal Leber hereditary optic neuropathy pedigree. Two germ-line mutations have arisen in members of one branch of the family, thereby leading to triplasmic descendants with three mitochondrial genotypes. Segregation toward the homoplasmic state can occur within a single generation in some of these descendants, a result that suggests rapid fixation of mitochondrial mutations as a result of developmental bottlenecking. However, slow segregation was observed in other offspring, and therefore no single or simple pattern of segregation can be generalized from the available data. Evidence for rare mtDNA recombination within the D-loop was obtained for one family member. In addition to these germ-line mutations, a somatic mutation was found in the D-loop of one family member. When this genealogical approach was applied to the nucleotide sequences of mitochondrial coding regions, the results again indicated a very rapid rate of evolution.
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Affiliation(s)
- N Howell
- Department of Radiation Therapy, University of Texas Medical Branch, Galveston 77555-0656, USA.
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Mackey DA, Oostra RJ, Rosenberg T, Nikoskelainen E, Bronte-Stewart J, Poulton J, Harding AE, Govan G, Bolhuis PA, Norby S. Primary pathogenic mtDNA mutations in multigeneration pedigrees with Leber hereditary optic neuropathy. Am J Hum Genet 1996; 59:481-5. [PMID: 8755941 PMCID: PMC1914749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) is one of the more common forms of hereditary optic neuropathy and one of the few mitochondrial neuropathies. Prior to the advent of molecular DNA testing, the diagnosis depended on the recognition of typical fundal changes, as well as a family history of maternal transmission. Sporadic cases were therefore diagnosed with a level of uncertainty. The aim of this study is to identify the proportion of patients with idiopathic bilateral optic neuropathy/atrophy who are suffering from LHON. METHODS Requests were sent to all ophthalmologists and neurologist in Australia and New Zealand for blood or hair follicle samples of patients with diagnosis of bilateral optic neuropathy/atrophy of uncertain aetiology for DNA testing by restriction endonuclease analysis. RESULTS One hundred and forty-four samples were received, of which 96 were sporadic cases of idiopathic optic atrophy. Eleven of these sporadic patients were found to harbour pathogenetic mitochondrial point mutations associated with LHON. CONCLUSIONS Our results indicated that 11% of patients with bilateral optic neuropathy/atrophy of uncertain aetiology are suffering from LHON. Comparing this data with all the known familial cases of LHON, we report that at least 8% of all LHON cases in Australia are sporadic. We concluded that mtDNA testing for LHON in patients with idiopathic optic atrophy should be included in the initial laboratory work-up.
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Affiliation(s)
- C Chan
- University of Melbourne, Department of Ophthalmology, St. Vincents Hospital, Victoria, Australia
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