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Corneal dystrophies describe a clinically and genetically heterogeneous group of inherited disorders. The International Classification of Corneal Dystrophies (IC3D) lists 22 types of corneal dystrophy, 17 of which have been demonstrated to result from pathogenic variants in 19 identified genes. In this study, we investigated the diagnostic yield of genetic testing in a well-characterised cohort of 58 individuals from 44 families with different types of corneal dystrophy. Individuals diagnosed solely with Fuchs endothelial corneal dystrophy were excluded. Clinical details were obtained from the treating ophthalmologist. Participants and their family members were tested using a gene candidate and exome sequencing approach. We identified a likely molecular diagnosis in 70.5% families (31/44). The detection rate was significantly higher among probands with a family history of corneal dystrophy (15/16, 93.8%) than those without (16/28, 57.1%, p = .015), and among those who had undergone corneal graft surgery (9/9, 100.0%) compared to those who had not (22/35, 62.9%, p = .041). We identified eight novel variants in five genes and identified five families with syndromes associated with corneal dystrophies. Our findings highlight the genetic heterogeneity of corneal dystrophies and the clinical utility of genetic testing in reaching an accurate clinical diagnosis., (© 2022 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Objective: Paediatric (childhood or congenital) cataract is an opacification of the normally clear lens of the eye and has a genetic basis in at least 18% of cases in Australia. This study aimed to replicate clinical gene screening to identify variants likely to be causative of disease in an Australian patient cohort., Methods and Analysis: Sixty-three reported isolated cataract genes were screened for rare coding variants in 37 Australian families using genome sequencing., Results: Disease-causing variants were confirmed in eight families with variant classification as 'likely pathogenic'. This included novel variants PITX3 p.(Ter303LeuextTer100), BFSP1 p.(Glu375GlyfsTer2), and GJA8 p.(Pro189Ser), as well as, previously described variants identified in genes GJA3, GJA8, CRYAA, BFSP1, PITX3, COL4A1 and HSF4 . Additionally, eight variants of uncertain significance with evidence towards pathogenicity were identified in genes: GJA3, GJA8, LEMD2, PRX, CRYBB1, BFSP2, and MIP ., Conclusion: These findings expand the genotype-phenotype correlations of both pathogenic and benign variation in cataract-associated genes. They further emphasise the need to develop additional evidence such as functional assays and variant classification criteria specific to paediatric cataract genes to improve interpretation of variants and molecular diagnosis in patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Intraocular anti-vascular endothelial growth factor (VEGF) therapies are the front-line treatment for diabetic macular edema (DME); however, treatment response varies widely. This study aimed to identify genetic determinants associated with anti-VEGF treatment response in DME. We performed a genome-wide association study on 220 Australian patients with DME treated with anti-VEGF therapy, genotyped on the Illumina Global Screening Array, and imputed to the Haplotype Reference Consortium panel. The primary outcome measures were changes in central macular thickness (CMT in microns) and best-corrected visual acuity (BCVA in ETDRS letters) after 12 months. Association between single nucleotide polymorphism (SNP) genotypes and DME outcomes were evaluated by linear regression, adjusting for the first three principal components, age, baseline CMT/BCVA, duration of diabetic retinopathy, and HbA1c. Two loci reached genome-wide significance (p < 5 × 10−8) for association with increased CMT: a single SNP on chromosome 6 near CASC15 (rs78466540, p = 1.16 × 10−9) and a locus on chromosome 12 near RP11-116D17.1 (top SNP rs11614480, p = 2.69 × 10−8). Four loci were significantly associated with reduction in BCVA: two loci on chromosome 11, downstream of NTM (top SNP rs148980760, p = 5.30 × 10−9) and intronic in RP11-744N12.3 (top SNP rs57801753, p = 1.71 × 10−8); one near PGAM1P1 on chromosome 5 (rs187876551, p = 1.52 × 10−8); and one near TBC1D32 on chromosome 6 (rs118074968, p = 4.94 × 10−8). In silico investigations of each locus identified multiple expression quantitative trait loci and potentially relevant candidate genes warranting further analysis. Thus, we identified multiple genetic loci predicting treatment outcomes for anti-VEGF therapies in DME. This work may potentially lead to managing DME using personalized treatment approaches.

Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease.

Nanophthalmos and posterior microphthalmos are ocular abnormalities in which both eyes are abnormally small, and typically associated with extreme hyperopia. We recruited 40 individuals from 13 kindreds with nanophthalmos or posterior microphthalmos, with 12 probands subjected to exome sequencing. Nine probands (69.2%) were assigned a genetic diagnosis, with variants in MYRF, TMEM98, MFRP, and PRSS56. Two of four PRSS56 families harbored the previously described c.1066dupC variant implicated in over half of all reported PRSS56 kindreds, with different surrounding haplotypes in each family suggesting a mutational hotspot. Individuals with a genetic diagnosis had shorter mean axial lengths and higher hyperopia than those without, with recessive forms associated with the most extreme phenotypes. These findings detail the genetic architecture of nanophthalmos and posterior microphthalmos in a cohort of predominantly European ancestry, their relative clinical phenotypes, and highlight the shared genetic architecture of rare and common disorders of refractive error., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Glaucoma, a disease characterized by progressive optic nerve degeneration, can be prevented through timely diagnosis and treatment. We characterize optic nerve photographs of 67,040 UK Biobank participants and use a multitrait genetic model to identify risk loci for glaucoma. A glaucoma polygenic risk score (PRS) enables effective risk stratification in unselected glaucoma cases and modifies penetrance of the MYOC variant encoding p.Gln368Ter, the most common glaucoma-associated myocilin variant. In the unselected glaucoma population, individuals in the top PRS decile reach an absolute risk for glaucoma 10 years earlier than the bottom decile and are at 15-fold increased risk of developing advanced glaucoma (top 10% versus remaining 90%, odds ratio = 4.20). The PRS predicts glaucoma progression in prospectively monitored, early manifest glaucoma cases (P = 0.004) and surgical intervention in advanced disease (P = 3.6 × 10 - 6 ). This glaucoma PRS will facilitate the development of a personalized approach for earlier treatment of high-risk individuals, with less intensive monitoring and treatment being possible for lower-risk groups.

Importance: Both primary and secondary forms of childhood glaucoma have many distinct causative mechanisms, and in many cases a cause is not immediately clear. The broad phenotypic spectrum of secondary glaucoma, particularly in individuals with variants in FOXC1 or PITX2 genes associated with Axenfeld-Rieger syndrome, makes it more difficult to diagnose patients with milder phenotypes. These cases are occasionally classified and managed as primary congenital glaucoma., Objective: To investigate the prevalence of FOXC1 variants in participants with a suspected diagnosis of primary congenital glaucoma., Design, Setting, and Participants: Australian and Italian cohorts were recruited from January 1, 2007, through March 1, 2016. Australian individuals were recruited through the Australian and New Zealand Registry of Advanced Glaucoma and Italian individuals through the Genetic and Ophthalmology Unit of l'Azienda Socio-Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Milan, Italy. We performed exome sequencing, in combination with Sanger sequencing and multiplex ligation-dependent probe amplification, to detect variants of FOXC1 in individuals with a suspected diagnosis of primary congenital glaucoma established by their treating specialist. Data analysis was completed from June 2015 to November 2017., Main Outcome and Measures: Identification of single-nucleotide and copy number variants in FOXC1, along with phenotypic characterization of the individuals who carried them., Results: A total of 131 individuals with a suspected diagnosis of primary congenital glaucoma were included. The mean (SD) age at recruitment in the Australian cohort was 24.3 (18.1) years; 37 of 84 Australian participants (44.0%) were female, and 71 of 84 (84.5%) were of European ancestry. The mean (SD) age at recruitment was 22.5 (18.4) years in the Italian cohort; 21 of 47 Italian participants (44.7%) were female, and 45 of 47 (95.7%) were of European ancestry. We observed rare, predicted deleterious FOXC1 variants in 8 of 131 participants (6.1%), or 8 of 166 participants (4.8%) when including those explained by variants in CYP1B1. On reexamination or reinvestigation, all of these individuals had at least 1 detectable ocular and/or systemic feature associated with Axenfeld-Rieger syndrome., Conclusions and Relevance: These data highlight the genetic and phenotypic heterogeneity of childhood glaucoma and support the use of gene panels incorporating FOXC1 as a diagnostic aid, especially because clinical features of Axenfeld-Rieger syndrome can be subtle. Further replication of these results will be needed to support the future use of such panels.

Mitochondrial haplogroups H1, H2 and UK have previously been reported to be associated with proliferative diabetic retinopathy (PDR) in Caucasian patients with diabetes. We aimed to replicate this finding with a larger sample and expand the analysis to include different severities of DR, and diabetic macular edema (DME). Caucasian participants (n = 2935) with either type 1 or type 2 diabetes from the Australian Registry of Advanced Diabetic Retinopathy were enrolled in this study. Twenty-two mitochondrial single nucleotide polymorphisms were genotyped by MassArray and haplogroups reconstructed using Haplogrep. Chi square tests and logistic regressions were used to test associations between haplogroup and DR phenotypes including any DR, non-proliferative DR (NPDR), proliferative DR (PDR) and DME. After stratifying the samples in type 1 and type 2 diabetes groups, and adjusting for sex, age, diabetes duration, concurrent HbA1c and hypertension, neither haplogroups H1, H2, UK, K or JT were associated with any DR, NPDR, PDR or DME.

Importance: The p.Gln368Ter (rs74315329) risk allele in the myocilin gene (MYOC) was initially reported to have high penetrance in glaucoma registry-based studies, but much lower estimates were recently obtained from population-based studies. We investigated this disparity using data from Australia and the United Kingdom., Objectives: To examine the penetrance and effect size of the MYOC p.Gln368Ter variant with glaucoma and ocular hypertension (OHT)., Design, Setting, and Participants: This cross-sectional study within the UK Biobank (UKBB) included participants of white British ancestry. Glaucoma cases were defined by International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) diagnoses and self-reported questionnaires. Carriers of the MYOC p.Gln368Ter variant were identified using genotype imputation from arrays. In contrast, 2 Australian registry-based studies, the Australian and New Zealand Registry of Advanced Glaucoma and the Glaucoma Inheritance Study in Tasmania, ascertained glaucoma cases referred by eye care clinicians, with historic control participants recruited from other Australian studies. Samples were either directly sequenced or had genotypes determined by imputation (for the Australian registry and historic control participants). Recruitment to the UKBB occurred between 2006 and 2010, and data analysis occurred from September 2017 to July 2018., Main Outcomes and Measures: The penetrance and odds ratio (OR) were estimated for the MYOC p.Gln368Ter variants in participants with glaucoma and OHT., Results: A total of 411 337 UKBB participants of white British ancestry (mean [SD] age, 56.6 [8.0] years) were included, plus 3071 Australian registry and 6750 historic control participants. In the UKBB, the minor allele frequency of the MYOC p.Gln368Ter variant was 1 in 786 individuals (0.13%). The odds ratio of p.Gln368Ter in patients with primary open-angle glaucoma (POAG) was 6.76 (95% CI, 4.05-11.29); glaucoma (POAG, self-reported glaucoma, and unspecified glaucoma), 4.40 (95% CI, 3.38-5.71); OHT, 3.56 (95% CI, 2.53-4.92); and OHT and glaucoma combined, 4.18 (95% CI, 3.05-5.67). The penetrance of the MYOC p.Gln368Ter variant was 7.6% in patients with glaucoma, 24.3% in patients with OHT, and 30.8% in patients with OHT and glaucoma combined. In the Australian registry studies, the odds of MYOC p.Gln368Ter variant were 12.16 (95% CI, 6.34-24.97) in patients with advanced glaucoma and 3.97 (95% CI, 1.55-9.75) in those with nonadvanced glaucoma; the penetrance of glaucoma was 56.1%, and penetrance in those considered to have glaucoma or be glaucoma suspects was 69.5%., Conclusions and Relevance: The MYOC p.Gln368Ter variant confers a very high-risk effect size for advanced glaucoma; the risk is lower in nonadvanced glaucoma and OHT. In the general population sample, approximately 50% of MYOC p.Gln368Ter carriers 65 years and older had glaucoma or OHT, with higher prevalence in the Australian registry studies.

Many genes have been suggested as candidate genes for keratoconus based on their function, their proximity to associated polymorphisms or due to the identification of putative causative variants within the gene. However, very few of these genes have been assessed for rare variation in keratoconus more broadly. In contrast, VSX1 and SOD1 have been widely assessed, however, the vast majority of studies have been small and the findings conflicting. In a cohort of Australians of European descent, consisting of 385 keratoconus cases and 396 controls, we screened 21 keratoconus candidate genes: BANP, CAST, COL4A3, COL4A4, COL5A1, FOXO1, FNDC3B, HGF, IL1A, IL1B, ILRN, IMMP2L, MPDZ, NFIB, RAB3GAP1, RAD51, RXRA, SLC4A11, SOD1, TF and VSX1. The candidate genes were sequenced in these individuals by either whole exome sequencing or targeted gene sequencing. Variants were filtered to identify rare (minor allele frequency <1%), potentially pathogenic variants. A total of 164 such variants were identified across the two groups with no variants fulfilling these criteria in cases in IL1RN, BANP, IL1B, RAD51 or SOD1. The frequency of variants was compared between cases and controls using chi-square or Fishers' Exact tests for each gene with at least one rare potentially pathogenic variant identified in the case cohort. The number of rare potentially pathogenic variants per gene ranged from three (RXRA) to 102 (MPDZ), however for all genes, there was no difference in the frequency between the cases and controls. We conclude that rare potentially pathogenic variation in the 21 candidate genes assessed do not play a major role in keratoconus susceptibility and pathogenesis., Competing Interests: Author Dr. Richard Lindsay is employed by Richard Lindsay and Associates. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products to declare.

Background: Diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are sight-threatening complications of diabetes mellitus and leading causes of adult-onset blindness worldwide. Genetic risk factors for diabetic retinopathy (DR) have been described previously, but have been difficult to replicate between studies, which have often used composite phenotypes and been conducted in different populations. This study aims to identify genetic risk factors for DME and PDR as separate complications in Australians of European descent with type 2 diabetes., Methods: Caucasian Australians with type 2 diabetes were evaluated in a genome-wide association study (GWAS) to compare 270 DME cases and 176 PDR cases with 435 non-retinopathy controls. All participants were genotyped by SNP array and after data cleaning, cases were compared to controls using logistic regression adjusting for relevant covariates., Results: The top ranked SNP for DME was rs1990145 (p = 4.10 × 10 - 6 , OR = 2.02 95%CI [1.50, 2.72]) on chromosome 2. The top-ranked SNP for PDR was rs918519 (p = 3.87 × 10 - 6 , OR = 0.35 95%CI [0.22, 0.54]) on chromosome 5. A trend towards association was also detected at two SNPs reported in the only other reported GWAS of DR in Caucasians; rs12267418 near MALRD1 (p = 0.008) in the DME cohort and rs16999051 in the diabetes gene PCSK2 (p = 0.007) in the PDR cohort., Conclusion: This study has identified loci of interest for DME and PDR, two common ocular complications of diabetes. These findings require replication in other Caucasian cohorts with type 2 diabetes and larger cohorts will be required to identify genetic loci with statistical confidence. There is considerable overlap in the patient cohorts with each retinopathy subtype, complicating the search for genes that contribute to PDR and DME biology.

Purpose: The Zinc Finger Protein 469 (ZNF469) gene has been proposed as a candidate gene for keratoconus due to the association of an upstream polymorphism (rs9938149) with the disease in two independent studies, and the role of the gene in the autosomal recessive disease Brittle Cornea Syndrome. Coding variants in ZNF469 have been assessed for association with keratoconus in several small studies, with conflicting results. We assessed rare, potentially pathogenic variants in ZNF469 for enrichment in keratoconus patients in a cohort larger than all previous studies combined., Methods: ZNF469 was sequenced in 385 Australian keratoconus patients of European descent, 346 population controls, and 230 ethnically matched screened controls by either whole exome sequencing or targeted gene sequencing. The frequency of rare and very rare potentially pathogenic variants was compared between cases and controls using χ2 or Fisher's exact tests and further explored using a gene based test (Sequence Kernel Association Test [SKAT]), weighting on the rarity of variants., Results: A total of 49 rare, including 33 very rare, potentially pathogenic variants were identified across all groups. No enrichment of rare or very rare potentially pathogenic variants in ZNF469 was observed in our cases compared to the control groups following analysis using χ2 or Fisher's exact tests. This finding was further supported by the SKAT results, which found no significant difference in the frequency of variants predicted to be damaging between cases and either control group (P = 0.06)., Conclusions: Rare variants in ZNF469 do not contribute to keratoconus susceptibility and do not account for the association at rs9938149.

Purpose: Primary open-angle glaucoma (POAG) and primary congenital glaucoma (PCG) with Mendelian inheritance are caused by mutations in at least nine genes. Utilizing whole-exome sequencing, we examined the disease burden accounted for by these known Mendelian glaucoma genes in a cohort of individuals with advanced early-onset POAG., Methods: The cases exhibited advanced POAG with young age of diagnosis. Cases and examined local controls were subjected to whole-exome sequencing. Nine hundred ninety-three previously sequenced exomes of Australian controls were called jointly with our dataset. Qualifying variants were selected based on predicted pathogenicity and rarity in public domain gene variant databases. Case-control mutational burdens were calculated for glaucoma-linked genes., Results: Two hundred eighteen unrelated POAG participants and 103 nonglaucomatous controls were included in addition to 993 unexamined controls. Fifty-eight participants (26.6%) harbored rare potentially pathogenic variants in known glaucoma genes. Enrichment of qualifying variants toward glaucoma was present in all genes except WDR36, in which controls harbored more variants, and TBK1, in which no qualifying variants were detected in cases or controls. After multiple testing correction, only MYOC showed statistically significant enrichment of qualifying variants (odds ratio [OR] = 16.62, P = 6.31×10-16)., Conclusions: Rare, potentially disease-causing variants in Mendelian POAG genes that showed enrichment in our dataset were found in 22.9% of advanced early-onset POAG cases. MYOC variants represented the largest monogenic cause in POAG. The association between WDR36 and POAG was not supported, and the majority of POAG cases did not harbor a potentially disease-causing variant in the remaining Mendelian genes.

Aims: This study aimed to investigate whether the single-nucleotide polymorphism (SNP) rs2910164 residing within microRNA-146a (miR-146a) is associated with diabetic microvascular complications diabetic nephropathy (DN), proliferative diabetic retinopathy (PDR) or diabetic macular oedema (DME) in either Caucasian patients with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus., Methods: Caucasian patients with T1DM (n = 733) or T2DM (n = 2215) were recruited from ophthalmology, renal and endocrine clinics in Australia and the UK. Patients with T2DM were required to have diabetes mellitus (DM) for at least 5 years and be on treatment with oral hypoglycaemic drugs or insulin. In total, 890 participants had DN (168 with T1DM and 722 with T2DM), 731 had PDR (251 with T1DM and 480 with T2DM) and 1026 had DME (170 with T1DM and 856 with T2DM). Participants were genotyped for SNP rs2910164 in miR-146a. Analyses investigating association were adjusted for relevant clinical covariates including age, sex, DM duration, HbA1c and hypertension., Results: A significant association was found between the C allele of rs2910164 and DN in the T1DM group (OR 1.93; CI 1.23-3.03; P = 0.004), but no association found in the T2DM group (OR 1.05; CI 0.83-1.32; P = 0.691). In the subset of T2DM patients, the C allele was specifically associated with DME (OR 1.25; CI 1.03-1.53; P = 0.025). No association with DME was found in the T1DM group (OR 0.87; CI 0.54-1.42); P = 0.583), or with PDR for either type of DM., Conclusions: Rs2910164 is significantly associated with microvascular complications DN in patients with T1DM and DME in patients with T2DM.

Aims/hypothesis: Diabetic retinopathy is a serious complication of diabetes mellitus and can lead to blindness. A genetic component, in addition to traditional risk factors, has been well described although strong genetic factors have not yet been identified. Here, we aimed to identify novel genetic risk factors for sight-threatening diabetic retinopathy using a genome-wide association study., Methods: Retinopathy was assessed in white Australians with type 2 diabetes mellitus. Genome-wide association analysis was conducted for comparison of cases of sight-threatening diabetic retinopathy (n = 336) with diabetic controls with no retinopathy (n = 508). Top ranking single nucleotide polymorphisms were typed in a type 2 diabetes replication cohort, a type 1 diabetes cohort and an Indian type 2 cohort. A mouse model of proliferative retinopathy was used to assess differential expression of the nearby candidate gene GRB2 by immunohistochemistry and quantitative western blot., Results: The top ranked variant was rs3805931 with p = 2.66 × 10(-7), but no association was found in the replication cohort. Only rs9896052 (p = 6.55 × 10(-5)) was associated with sight-threatening diabetic retinopathy in both the type 2 (p = 0.035) and the type 1 (p = 0.041) replication cohorts, as well as in the Indian cohort (p = 0.016). The study-wide meta-analysis reached genome-wide significance (p = 4.15 × 10(-8)). The GRB2 gene is located downstream of this variant and a mouse model of retinopathy showed increased GRB2 expression in the retina., Conclusions/interpretation: Genetic variation near GRB2 on chromosome 17q25.1 is associated with sight-threatening diabetic retinopathy. Several genes in this region are promising candidates and in particular GRB2 is upregulated during retinal stress and neovascularisation.

Keratoconus is a degenerative eye condition which results from thinning of the cornea and causes vision distortion. Treatments such as ultraviolet (UV) cross-linking have proved effective for management of keratoconus when performed in early stages of the disease. The central corneal thickness (CCT) is a highly heritable endophenotype of keratoconus, and it is estimated that up to 95% of its phenotypic variance is due to genetics. Genome-wide association efforts of CCT have identified common variants (i.e. minor allele frequency (MAF) >5%). However, these studies typically ignore the large set of exonic variants whose MAF is usually low. In this study, we performed a CCT exome-wide association analysis in a sample of 1029 individuals from a population-based study in Western Australia. We identified a genome-wide significant exonic variant rs121908120 (P = 6.63 × 10(-10)) in WNT10A. This gene is 437 kb from a gene previously associated with CCT (USP37). We showed in a conditional analysis that the WNT10A variant completely accounts for the signal previously seen at USP37. We replicated our finding in independent samples from the Brisbane Adolescent Twin Study, Twin Eye Study in Tasmania and the Rotterdam Study. Further, we genotyped rs121908120 in 621 keratoconus cases and compared the frequency to a sample of 1680 unscreened controls from the Queensland Twin Registry. We found that rs121908120 increases the risk of keratoconus two times (odds ratio 2.03, P = 5.41 × 10(-5))., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Importance: Juvenile open-angle glaucoma (JOAG) is a severe neurodegenerative eye disorder in which most of the genetic contribution remains unexplained., Objective: To assess the prevalence of pathogenic CYP1B1 sequence variants in an Australian cohort of patients with JOAG and severe visual field loss., Design, Setting, and Participants: For this cohort study, we recruited 160 patients with JOAG classified as advanced (n = 118) and nonadvanced (n = 42) through the Australian and New Zealand Registry of Advanced Glaucoma from January 1, 2007, through April 1, 2014. Eighty individuals with no evidence of glaucoma served as a control group. We defined JOAG as diagnosis before age 40 years and advanced JOAG as visual field loss in 2 of the 4 central fixation squares on a reliable visual field test result. We performed direct sequencing of the entire coding region of CYP1B1. Data analysis was performed in October 2014., Main Outcomes and Measures: Identification and characterization of CYP1B1 sequence variants., Results: We identified 7 different pathogenic variants among 8 of 118 patients with advanced JOAG (6.8%) but none among the patients with nonadvanced JOAG. Three patients were homozygous or compound heterozygous for CYP1B1 pathogenic variants, which provided a likely basis for their disease. Five patients were heterozygous. The allele frequency among the patients with advanced JOAG (11 in 236 [4.7%]) was higher than among our controls (1 in 160 [0.6%]; P = .02; odds ratio, 7.8 [95% CI, 0.02-1.0]) or among the control population from the Exome Aggregation Consortium database (2946 of 122 960 [2.4%]; P = .02; odds ratio, 2.0 [95% CI, 0.3-0.9]). Individuals with CYP1B1 pathogenic variants, whether heterozygous or homozygous, had worse mean (SD) deviation on visual fields (-24.5 [5.1] [95% CI, -31.8 to -17.2] vs -15.6 [10.0] [95% CI, -17.1 to -13.6] dB; F1,126 = 5.90; P = .02; partial ηp2 = 0.05) and were younger at diagnosis (mean [SD] age, 23.1 [8.4] [95% CI, 17.2-29.1] vs 31.5 [8.0] [95% CI, 30.1-33.0] years; F1,122 = 7.18; P = .008; ηp2 = 0.06) than patients without CYP1B1 pathogenic variants., Conclusions and Relevance: Patients with advanced JOAG based on visual field loss had enrichment of CYP1B1 pathogenic variants and a more severe phenotype compared with unaffected controls and patients with nonadvanced JOAG.

Purpose: To investigate the presence of TBK1 copy number variations in a large, well-characterized Australian cohort of patients with glaucoma comprising both normal-tension glaucoma and high-tension glaucoma cases., Design: A retrospective cohort study., Methods: DNA samples from patients with normal-tension glaucoma and high-tension glaucoma and unaffected controls were screened for TBK1 copy number variations using real-time quantitative polymerase chain reaction. Samples with additional copies of the TBK1 gene were further tested using custom comparative genomic hybridization arrays., Results: Four out of 334 normal-tension glaucoma cases (1.2%) were found to carry TBK1 copy number variations using quantitative polymerase chain reaction. One extra dose of the TBK1 gene (duplication) was detected in 3 normal-tension glaucoma patients, while 2 extra doses of the gene (triplication) were detected in a fourth normal-tension glaucoma patient. The results were further confirmed by custom comparative genomic hybridization arrays. Further, the TBK1 copy number variation segregated with normal-tension glaucoma in the family members of the probands, showing an autosomal dominant pattern of inheritance. No TBK1 copy number variations were detected in 1045 Australian patients with high-tension glaucoma or in 254 unaffected controls., Conclusion: We report the presence of TBK1 copy number variations in our Australian normal-tension glaucoma cohort, including the first example of more than 1 extra copy of this gene in glaucoma patients (gene triplication). These results confirm TBK1 to be an important cause of normal-tension glaucoma, but do not suggest common involvement in high-tension glaucoma., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The purpose of this review is to compare the prevalence of diabetic retinopathy (DR) between Indigenous and non-Indigenous Australians with Diabetes Mellitus (DM). Australian DR prevalence data from 6 Indigenous studies (n = 2865) and 5 non-Indigenous studies (n = 9801) conducted between 1985 and 2013 were included for analysis. Estimated prevalence of any DR among Indigenous Australians with DM was 23.4% compared with 28.9% for non-Indigenous Australians (χ(2)  = 26.9, P < 0.001). In studies performed after 1990, a significantly higher rate of diabetic macular edema was found in Indigenous compared with non-Indigenous Australians with DM (7.6% versus 4.9%, χ(2)  = 6.67, P = 0.01). Although there are limitations in comparing these studies, one explanation for the observed data could be a model in which Indigenous Australians are relatively resistant to early stage DR, but with a subset progressing to sight threatening DR due to individual genetic and environmental susceptibility factors coupled with poor glycemic control., (© 2014 Royal Australian and New Zealand College of Ophthalmologists.)

Primary open-angle glaucoma (POAG) is a major cause of irreversible blindness worldwide. We performed a genome-wide association study in an Australian discovery cohort comprising 1,155 cases with advanced POAG and 1,992 controls. We investigated the association of the top SNPs from the discovery stage in two Australian replication cohorts (932 cases and 6,862 controls total) and two US replication cohorts (2,616 cases and 2,634 controls total). Meta-analysis of all cohorts identified three loci newly associated with development of POAG. These loci are located upstream of ABCA1 (rs2472493[G], odds ratio (OR) = 1.31, P = 2.1 × 10(-19)), within AFAP1 (rs4619890[G], OR = 1.20, P = 7.0 × 10(-10)) and within GMDS (rs11969985[G], OR = 1.31, P = 7.7 × 10(-10)). Using RT-PCR and immunolabeling, we show that these genes are expressed within human retina, optic nerve and trabecular meshwork and that ABCA1 and AFAP1 are also expressed in retinal ganglion cells.

Objective: Selenium is effective in improving quality of life and reducing the progression of active Graves' orbitopathy. The effect of correcting relative selenium deficiency on improving Graves' orbitopathy is unknown, as baseline selenium levels have not previously been measured. The study aims to determine whether serum selenium levels are reduced in patients with Graves' disease with orbitopathy (GO) compared with without orbitopathy (GD)., Design: A prospective, case-control study performed between 2009 and 2012 at endocrine and ophthalmology clinics in Australia., Patients: A total of 198 patients with Graves' disease participated in the study: 101 with Graves' orbitopathy and 97 without Graves' orbitopathy., Measurements: Serum selenium levels in both groups., Results: Mean serum selenium levels were significantly lower in GO (1·10 ± 0·18 μm) than in GD (1·19 ± 0·20 μm) (P = 0·001). Mean selenium levels appeared to decrease in parallel with increasing severity of GO; selenium level was 1·19 ± 0·20 μm in GD, 1·10 ± 0·19 μm in moderate-to-severe GO and 1·09 ± 0·17 μm in sight-threatening GO (P = 0·003). Serum selenium levels remained significantly lower in GO after adjusting for age, smoking status, thyroidectomy, radioactive iodine treatment and residential location., Conclusion: Serum selenium levels are lower in patients with GO compared with GD in an Australian study population with marginal selenium status. Relative selenium deficiency may be an independent risk factor for orbitopathy in patients with Graves' disease., (© 2013 John Wiley & Sons Ltd.)

Congenital cataract is the most common cause of treatable visual impairment in children worldwide. Mutations in many different genes lead to congenital cataract. Recently, mutations in the receptor tyrosine kinase gene, EPHA2, have been found to cause congenital cataract in six different families. Although these findings have established EPHA2 as a causative gene, the total contribution of mutations in this gene to congenital cataract is unknown. In this study, for the first time, a population-based approach was used to investigate the frequency of disease causing mutations in the EPHA2 gene in inherited cataract cases in South-Eastern Australia. A cohort of 84 familial congenital or juvenile cataract index cases was screened for mutations in the EPHA2 gene by direct sequencing. Novel changes were assessed for segregation with the disease within the family and in unrelated controls. Microsatellite marker analysis was performed to establish any relationship between families carrying the same mutation. We report a novel congenital cataract causing mutation c.1751C>T in the EPHA2 gene and the previously reported splice mutation c.2826-9G>A in two new families. Additionally, we report a rare variant rs139787163 potentially associated with increased susceptibility to cataract. Thus mutations in EPHA2 account for 4.7% of inherited cataract cases in South-Eastern Australia. Interestingly, the identified rare variant provides a link between congenital and age-related cataract.

Purpose: Keratoconus is a common complex corneal ectasia that can lead to severe visual impairment. Although a genetic component is well recognized, the genetic risk factors for keratoconus are yet to be fully elucidated. A recent genome-wide association study (GWAS) by Li et al. identified 15 potentially associated single nucleotide polymorphisms (SNPs). Here, we aimed to replicate these associations, and conduct a meta-analysis of the current and previous studies., Methods: We genotyped the 15 reported associated SNPs in 524 Australian Caucasian cases with keratoconus and 2761 controls. Association analysis was conducted in PLINK. A meta-analysis of this study with the adjusted P values of the previously published GWAS was conducted using the method of Fisher to combine P values., Results: Our Australian cohort showed association (P < 0.003) at SNPs near RAB3GAP1, KCND3, IMMPL2, and in a gene desert on chromosome 13q33.3, providing evidence of replication of the published results. The meta-analysis showed SNP rs4954218 near RAB3GAP1 gene was associated significantly with keratoconus, with P = 9.26 × 10(-9) passing the genome-wide significance level., Conclusions: Although the mechanism of disease association is yet to be determined, SNP rs4954218 is associated consistently with keratoconus and likely tags a functional variant that contributes to disease susceptibility.

Purpose: A recent large genome-wide association study (GWAS) identified multiple variants associated with primary angle-closure glaucoma (PACG). The present study investigated the role of these variants in two cohorts with PACG recruited from Australia and Nepal., Method: Patients with PACG and appropriate controls were recruited from eye clinics in Australia (n = 232 cases and n = 288 controls) and Nepal (n = 106 cases and 204 controls). Single nucleotide polymorphisms (SNPs) rs3753841 (COL11A1), rs1015213 (located between PCMTD1 and ST18), rs11024102 (PLEKHA7), and rs3788317 (TXNRD2) were selected and genotyped on the Sequenom. Analyses were conducted using PLINK and METAL., Results: After adjustment for age and sex, SNP rs3753841 was found to be significantly associated with PACG in the Australian cohort (p = 0.017; OR = 1.34). SNPs rs1015213 (p = 0.014; OR 2.35) and rs11024102 (p = 0.039; OR 1.43) were significantly associated with the disease development in the Nepalese cohort. None of these SNPs survived Bonferroni correction (p = 0.05/4 = 0.013). However, in the combined analysis, of both cohorts, rs3753841 and rs1015213 showed significant association with p-values of 0.009 and 0.004, respectively both surviving Bonferroni correction. SNP rs11024102 showed suggestive association with PACG (p-value 0.035) and no association was found with rs3788317., Conclusion: The present results support the initial GWAS findings, and confirm the SNP's contribution to PACG. This is the first study to investigate these loci in both Australian Caucasian and Nepalese populations.

Purpose: To ascertain if single nucleotide polymorphisms (SNPs) involved in the determination of central corneal thickness, optic disc area, and vertical cup-to-disc ratio (VCDR) also are associated with open-angle glaucoma (OAG)., Design: Retrospective case-control genetic association study., Methods: A total of 16 SNPs associated with central corneal thickness, optic disc area, and VCDR were genotyped in 876 OAG cases and 883 normal controls. To determine if the SNPs were also correlated with OAG severity, the cohort was stratified into advanced OAG (n = 326) and nonadvanced OAG (n = 550). Both the cases and controls were of European descent and were recruited from within Australia., Results: Two VCDR SNPs were found to be significantly associated with OAG after correction for multiple testing. The 2 SNPs were rs10483727, found adjacent to the SIX1 gene (P = 6.2 × 10(-06); odds ratio, 1.38; 95% confidence interval, 1.20 to 1.59), and rs1063192, found within the CDKN2B gene (P = 2.2 × 10(-05); odds ratio, 0.74; 95% confidence interval, 0.64 to 0.85). The CDKN2B variant rs1063192 also was found to be associated more strongly with advanced OAG., Conclusions: The findings from this study indicate that variants influencing VCDR are also risk alleles for OAG in our Australian cohort of European descent. The identification of SIX1 and CDKN2B as susceptibility loci will assist in understanding the pathologic mechanisms involved in the development of OAG., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

Background:   Glaucoma is a sight-threatening disease affecting 3% of the population over the age of 50. Glaucoma is treatable, and severe vision loss can usually be prevented if diagnosis is made at an early stage. Genetic factors play a major role in the pathogenesis of the condition, and therefore, genetic testing to identify asymptomatic at-risk individuals is a promising strategy to reduce the prevalence of glaucoma blindness. Furthermore, unravelling genetic risk factors for glaucoma would also allow a better understanding of the pathogenesis of the condition and the development of new treatments., Design:   The Australian and New Zealand Registry of Advanced Glaucoma is a prospective study that aims to develop a large cohort of glaucoma cases with severe visual field loss to identify novel genetic risk factors for glaucoma blindness., Methods:   Clinical information and blood are collected from participants after referral by eye practitioners. Samples are collected across Australia and New Zealand using postage kits., Participants:   Our registry has recruited just over 2000 participants with advanced glaucoma, as well as secondary and developmental glaucomas., Results:   A positive family history of glaucoma is present in more than half of the advanced glaucoma cases and the age at diagnosis is significantly younger for participants with affected relatives, which reinforces the involvement of genetic factors in glaucoma., Conclusions:   With the collection of glaucoma cases recruited so far, our registry aims to identify novel glaucoma genetic risk factors to establish risk profiling of the population and protocols for genetic testing., (© 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.)

Fuchs' endothelial dystrophy (FED) is a disease affecting the corneal endothelium. Recent studies reported significant association of polymorphisms in the TCF4 (transcription factor 4) gene, and a borderline association of PTPRG (protein tyrosine phosphatase, receptor type, G) variants with late-onset FED in Caucasians from the United States. Association of TCF4 has also been reported in the Chinese population. We aimed to determine association of the reported polymorphisms in TCF4 and PTPRG, and association of polymorphisms in the candidate genes ZEB1 (zinc-finger E-box binding homoebox 1), COL8A2 (collagen, type VIII, alpha 2), TGFBI (transforming growth factor, β-induced) and CLU (clusterin) in Australian cases. We also compared the expression of TGFBI and CLU proteins between FED and normal whole corneas. In all, 30 single-nucleotide polymorphisms (SNPs) from the candidate genes were genotyped in 103 cases and 275 controls. Each SNP and haplotype was assessed for association with the disease. SNP analysis identified an association of TCF4 (rs613872 (P=5.25 × 10(-15), OR=4.05), rs9954153 (P=3.37 × 10(-7), OR=2.58), rs2286812 (P=4.23 × 10(-6), OR=2.55) and rs17595731 (P=3.57 × 10(-5), OR=3.79)), CLU (rs17466684; P=0.003, OR=1.85) and one haplotype of TGFBI SNPs (P=0.011, OR=2.29) with FED in Caucasian Australians. No evidence for genetic association of PTPRG, ZEB1 and COL8A2 was found. Immunohistochemistry showed differential expression of CLU and TGFBI proteins in FED-affected compared with normal corneas. In conclusion, variation in TCF4, CLU and TGFBI, but not PTPRG, ZEB1 and COL8A2 genes are associated with FED in Caucasian Australian cases. Differential expression of CLU and TGFBI proteins in FED-affected corneas provides novel insights into the disease mechanism.

Purpose: To describe the phenotype of ocular hypertension and primary open-angle glaucoma in a family with individuals compound heterozygote for Gln368STOP and Thr377Met myocilin (MYOC) mutations., Methods: Family members of the proband underwent comprehensive ocular clinical examination and DNA sequencing for MYOC mutations., Results: A 34-year-old woman with marked ocular hypertension was found to carry Gln368STOP and Thr377Met MYOC mutations. Three other siblings carried both mutations, while one carried Gln368STOP alone. Three of five siblings had received treatment for ocular hypertension or early glaucoma, with the average age of diagnosis 28 years; one required trabeculectomy at age 27. The mother of the proband was found to be a carrier for Gln368STOP alone, which indicates that her offspring with both Gln368STOP and Thr377Met carry variants on opposing alleles., Conclusions: This pedigree is the first report with individuals compound heterozygote for the two most common glaucoma-causing MYOC variants. The combination of mutations manifests a more severe phenotype than either alone. Identification of gene changes associated with glaucoma within the family has enabled unaffected members to stratify their risk of future disease and institute closer monitoring and early treatment.

Purpose: To investigate the underlying genetic variation between candidate genes and primary angle closure glaucoma (PACG) in both Nepalese and Australian populations., Methods: A total of 213 patients with PACG (106 Nepalese and 107 Australian) and 492 age and sex matched controls (204 Nepalese and 288 Australian) were included in the current study. Three candidate genes were selected; methyl-tetrahydrofolate reductase (MTHFR), calcitonin receptor-like receptor gene (CALCRL), and membrane frizzled-related protein (MFRP). Tag single nucleotide polymorphisms (SNPs) were selected and genotyped to capture the majority of common variation across each locus. Allele and haplotype analyses were conducted using PLINK., Results: SNPs in the nanophthalmos gene MFRP were found to be nominally associated with PACG under the allelic model. Two SNPs were associated in the Australian cohort (rs948414; p=0.02 and rs36015759; p=0.02), and a single SNP in the Nepalese cohort (rs10790289; p=0.03), however these SNPs failed to remain significant after adjustment for sex and age. A haplotype at the CALCRL gene (AATACAGAT) was associated in the Australian cohort (corrected p-value=0.024). No association was observed in either cohort for MTHFR., Conclusions: This study implicates genetic variation at the CALCRL gene in the pathogenesis of PACG in an Australian Caucasian cohort. Additionally, the MFRP gene shows tendency to be associated with PACG in both the Australian and Nepalese cohorts. Further investigation in a larger cohort is warranted to confirm these findings. No statistically significant associations were identified between MTHFR and PACG in either population.

Purpose: To investigate the association between genetic variation at the matrix metalloproteinase-9 (MMP9) locus and primary angle closure glaucoma (PACG) in an Australian Caucasian population., Methods: A total of 107 Australian patients with PACG and 288 age and sex-matched controls were included in the current study. Tag single nucleotide polymorphisms (SNPs) were selected and genotyped to cover the majority of common variation within MMP9. Allele, genotype and haplotype association analyses were conducted using PLINK., Results: Two SNPs from MMP9, rs3918249 and rs17576 were significantly associated under the allelic model with p values of 0.006 for both SNPs. In addition, haplotype analysis revealed a protective haplotype TACGG to be significantly more frequent in controls (69%) than in PACG cases (59%), with p=0.006., Conclusions: This study demonstrates an association between MMP9 SNPs rs3918249 and rs17576 and PACG in the Australian population, suggesting MMP9 may be involved in the pathogenesis of this blinding disease. Further replication will be helpful in confirming this finding before future clinical translation.

Purpose: Acute anterior uveitis (AAU) is the most common form of uveitis; however, while it is presumed to have an immunological basis, the precise underlying etiology remains elusive. Toll-like receptors (TLRs) have a key role in linking innate and adaptive immunity, thereby forming a molecular bridge between microbial triggers and the development of AAU. The purpose of this study was to investigate the role of TLR2 and TLR4 gene polymorphisms in the pathogenesis of AAU., Methods: The study comprised 225 confirmed cases of idiopathic or human leukocyte antigen (HLA) B27 (subtypes B*2701-2759; HLA-B27)-related AAU and 2,534 population-based controls from the Blue Mountains Eye Study. All participants were of Anglo-Celtic descent. Blood samples were collected for DNA extraction and genotyping. A total of 16 single nucleotide polymorphisms (SNPs) were selected for analysis and either directly genotyped or imputed to cover the common variations within the TLR genes. Data were analyzed at the allelic, genotypic and haplotypic levels., Results: Control subjects were significantly older than case subjects (p<0.0001). There was no significant difference in the gender composition between the case and control cohorts (p=0.18). One TLR2 SNP (rs11938228) was found to be associated with AAU at the allelic level (OR=1.28; p=0.017); however this association did not remain following adjustment for age and sex (p=0.067). None of the SNPs at the TLR4 locus were found to differ significantly between cases or controls, irrespective of adjustment for age and gender., Conclusions: This study has confirmed that common TLR variants of moderate effect size do not predispose to AAU, undermining the implication of reported mutations in the selective perturbations of TLR expression and function evident in AAU.

Background: A novel phenotype consisting of cataract, mental retardation, erythematous skin rash and facial dysmorphism was recently described in an extended pedigree of Australian Aboriginal descent. Large scale chromosomal re-arrangements had previously been ruled out. We have conducted a genome-wide scan to map the linkage region in this family., Methods: Genome-wide linkage analysis using Single Nucleotide Polymorphism (SNP) markers on the Affymetrix 10K SNP array was conducted and analysed using MERLIN. Three positional candidate genes (ZBTB17, EPHA2 and EPHB2) were sequenced to screen for segregating mutations., Results: Under a fully penetrant, dominant model, the locus for this unique phenotype was mapped to chromosome 1p35.3-p36.32 with a maximum LOD score of 2.41. The critical region spans 48.7 cM between markers rs966321 and rs1441834 and encompasses 527 transcripts from 364 annotated genes. No coding mutations were identified in three positional candidate genes EPHA2, EPHB2 or ZBTB17. The region overlaps with a previously reported region for Volkmann cataract and the phenotype has similarity to that reported for 1p36 monosomy., Conclusions: The gene for this syndrome is located in a 25.6 Mb region on 1p35.3-p36.32. The known cataract gene in this region (EPHA2) does not harbour mutations in this family, suggesting that at least one additional gene for cataract is present in this region.

Osteogenesis imperfecta (OI) is a rare connective tissue disorder caused by mutations in the type I collagen genes, COL1A1 and COL1A2, and is characterised by low bone mass and bone fragility. In this study, we explored the relationship between type 1 collagen genes and the quantitative trait central corneal thickness (CCT). CCT was measured in a cohort of 28 Australian type I OI patients and mean CCT was found to be significantly lower compared to a normal population (P < 0.001). We then investigated CCT and corneal collagen fibril diameter and density in a mouse model of OI with a col1a2 mutation. Mean CCT was significantly lower in mutant mice (P = 0.002), as was corneal collagen fibril diameter (P = 0.034), whilst collagen fibril density was significantly greater in mutants (P = 0.034). Finally, we conducted a genetic study to determine whether common single nucleotide polymorphisms (SNPs) in COL1A1 and COL1A2 are associated with CCT variation in the normal human population. Polymorphism rs2696297 (P = 0.003) in COL1A1 and a three SNP haplotype in COL1A2 (P = 0.007) were all significantly associated with normal CCT variation. These data implicate type 1 collagen in the determination of CCT in both OI patients and normal individuals. This provides the first evidence of quantitative trait loci that influence CCT in a normal population and has potential implications for investigating genes involved in glaucoma pathogenesis, a common eye disease in which the severity and progression is influenced by CCT.

Keratoconus is a debilitating ocular disease characterised by progressive asymmetrical thinning of the cornea, the clear covering at the front of the eye. The resulting protrusion of the cornea results in severe refractive error, in the most severe cases requiring corneal grafting. It is a complex disease with a genetic component. Despite several reports of linked loci, major gene identification has been elusive. A genome-wide linkage scan in a large Australian pedigree with apparent autosomal dominant keratoconus was conducted using the Affymetrix 10K SNP chip and two regions of linkage identified. Functional candidate genes from within both linkage peaks were assessed for corneal expression and screened for mutations in affected family members. Equal evidence of linkage was detected to both 1p36.23-36.21 and 8q13.1-q21.11 with LOD scores of 1.9. Analysis of both loci concurrently suggests digenic linkage with two-locus LOD score of 3.4. All affected individuals carry identical haplotypes at both loci. Carriers of either linked haplotype without the other do not have keratoconus. No mutations were identified in the following candidate genes expressed in the cornea: ENO1, CTNNBIP1, PLOD1, UBIAD1, SPSB1 or TCEB1. Although the pedigree appears to demonstrate simple autosomal dominant inheritance, the disorder is actually genetically complex. This pedigree may provide a link between inherited forms of keratoconus and sporadic cases.

Pseudoexfoliation syndrome is a generalized disorder of the extracellular matrix, characterized by the pathological accumulation of abnormal fibrillar material in the anterior segment of the eye predisposing to glaucomatous optic neuropathy. We investigated the role of lysyl oxidase-like 1(LOXL1) sequence variation in a Caucasian Australian population-based cohort of 2508 individuals, 86 (3.4%) of whom were diagnosed with pseudoexfoliation syndrome. Two non-synonymous variants in exon 1 of LOXL1 (Arg141Leu;Gly153Asp) were found to be strongly associated with pseudoexfoliation. Two copies of the high risk haplotype at these single-nucleotide polymorphisms conferred a risk of 7.20 (95%CI: 3.04-20.75) compared with no copies of the high risk haplotype. Each of the disease-associated alleles is by far commoner in the normal population, and examination of cross-species homology reveals that the two disease-associated coding variants belong to the ancestral version of the gene. LOXL1 was found to be expressed by reverse transcription-polymerase chain reaction in all ocular tissues examined except retina. The presence of LOXL1 protein in ocular tissues of interest was demonstrated by western blotting. Specific bands of approximately 130 and 80 kDa, representing polymerized protein forms, were detected in the cornea, iris, ciliary body, lens capsule and optic nerve. The 42 kDa mature form of LOXL1 was detected in the iris and ciliary body. Our Caucasian population has a 9-fold lower lifetime incidence of pseudoexfoliation syndrome compared with Nordic populations despite having similar allelic architecture at the LOXL1 locus. This strongly suggests that as yet unidentified genetic or environmental factors independent of LOXL1 strongly influence the phenotypic expression of the syndrome.

Purpose: To identify the causative gene for autosomal dominant total congenital cataract in a six-generation Australian family displaying linkage to chromosome 1p36., Methods: Eight candidate genes (HSPB7, FBXO42, EFHD2, ZBTB17, CAPZB, FBLIM1, ALDH4A1, and MFAP2) from within the previously defined linkage interval were selected based on expression in lens and their known or putative function. The coding exons were sequenced in multiple affected family members and compared to the reference sequence., Results: No segregating mutations were identified in any of the eight genes. Thirty-one polymorphisms were detected, 20 of which were in the exons and 11 in the flanking introns., Conclusions: Coding mutations in HSPB7, FBXO42, EFHD2, ZBTB17, CAPZB, FBLIM1, ALDH4A1, and MFAP2 do not account for congenital cataract in this family.

Purpose: Congenital cataract is a significant cause of blindness worldwide. Many genes are known to cause the disorder. A large multigenerational pedigree was investigated for the genetic cause of a posterior polar autosomal dominant congenital cataract., Methods: A genome wide scan was conducted in a large multigenerational family with autosomal dominant cataract to identify the linked region of the genome. The PITX3 gene was investigated through direct sequencing and detection of fluorescently labeled PCR products., Results: Linkage was detected to a region of chromosome 10q23-26 which contains the candidate gene PITX3. A segregating 17 bp insertion mutation was identified. This mutation was not identified in 100 additional unrelated sporadic and familial congenital cataract patients. No mutations of the PITX3 gene were identified in 9 families with posterior polar congenital cataract., Conclusions: The 657ins17bp duplication of the PITX3 gene is the cause of the cataract phenotype in the large pedigree, however, this gene appears responsible for only a small proportion of congenital cataract in Australia.

Nance-Horan syndrome (NHS) is an X-linked disorder characterized by congenital cataracts, dental anomalies, dysmorphic features, and, in some cases, mental retardation. NHS has been mapped to a 1.3-Mb interval on Xp22.13. We have confirmed the same localization in the original, extended Australian family with NHS and have identified protein-truncating mutations in a novel gene, which we have called "NHS," in five families. The NHS gene encompasses approximately 650 kb of genomic DNA, coding for a 1,630-amino acid putative nuclear protein. NHS orthologs were found in other vertebrates, but no sequence similarity to known genes was identified. The murine developmental expression profile of the NHS gene was studied using in situ hybridization and a mouse line containing a lacZ reporter-gene insertion in the Nhs locus. We found a complex pattern of temporally and spatially regulated expression, which, together with the pleiotropic features of NHS, suggests that this gene has key functions in the regulation of eye, tooth, brain, and craniofacial development.