Association of ARMS2 genotype with bilateral involvement of exudative age-related macular degeneration

Association between the ARMS2 rs10490924 risk genotype and dry-age related macular degeneration patients with and without reticular pseudodrusen in a Turkish population: findings from a study conducted at a tertiary clinic

PURPOSE

To evaluate the relationship between the presence of reticular pseudodrusen (RPD) and the risk allele of ARMS2 rs10490924 variation in dry-AMD patients by using multimodal imaging. Also, to compare patients with and without RPD and healthy volunteers according to the distribution of the risk allele.

METHODS

In this cross-sectional study, dry-AMD patients with (Group A, n = 50) and without (Group B, n = 50) RPD and healthy volunteers (Group C, n = 50) were enrolled. After detailed ophthalmologic examination, confocal scanning laser ophthalmoscope (Heidelberg, Germany) was used to acquire near infra-red (NIR) imaging for RPD and the diagnosis was confirmed by Spectral Domain-Optical coherence tomography (Heidelberg, Germany). In silent choroidal neovascularization suspicion, optical coherence tomography angiography (Optovue, Fremont, CA) was performed and those were excluded. For genetic assessment, peripheric blood sampling was performed. Using next-generation sequencing technique (NGS), ARMS2 rs10490924 single nucleotide polymorphism was investigated. Groups were compared according to the distribution of the risky allele.

RESULTS

150 eyes of 150 participants were included. In Group A, 42% (21) of patients were heterozygous for the T risk allele, 30% (15) were homozygous, and the risk allele was not detected in 28% (14). In Group B, 44% (22) of patients were heterozygous, 17% (8) were homozygous, and the risk allele was not detected in 39% (20). In Group C, 30% (15) of participants were heterozygous, 4% (2) were homozygous, and variation was not observed in 64% (32). Homozygous participants in Group A were significantly higher than other two groups (Group A-B: OR = 2.67, 95% CI: 0.895, 8.020; Group A-C: OR = 17.14, 95% CI: 3.449, 85.208) while in Group B, homozygous individuals were higher than Group C (respectively, p values 0.0039, 0.0002, 0.013). T risky allele frequencies were 51%, 38%, and 20% in Groups A, B, and C, respectively, which was significantly higher in Group A (p = 0.02).

CONCLUSION

Genetic influence in AMD is inevitable while certain differences according to different ethnicities may apply. Association of genetic variations and imaging findings like RPD is lacking among literature for different populations. By the aspect of this study, the relationship between RPD and ARMS2 rs10490924 polymorphism in dry-AMD patients were highlighted among Turkish population by using multimodal imaging for the first time.

KEY MESSAGES

What is Known? Pathophysiology of age-related macular degeneration is influenced from multiple factors including single nucleotide polymorphisms. The variations of ARMS2 are suspected well in the current literature. Reticular pseudodrusen is related to advanced stages of age related macular degeneration disease. What is New? The ARMS2 rs10490924 risk genotype is associated with the presence of reticular pseudodrusen in dry age related macular degeneration patients. Homozygous genotype of T risk allele is evaluated significantly higher in dry age related macular degeneration patients with reticular pseudodrusen.

Characteristics of Pachychoroid Diseases and Age-Related Macular Degeneration: Multimodal Imaging and Genetic Backgrounds

The emergence of pachychoroid disease is changing the concept of age-related macular degeneration (AMD). The concept of pachychoroid diseases was developed through clinical observation of multimodal images of eyes with AMD and central serous chorioretinopathy; however, recent genetic studies have provided a proof of concept for pachychoroid spectrum disease, which should be differentiated from drusen-driven AMD. The genetic confirmation of pachychoroid concept further provides novel viewpoints to decode previously reported findings, which facilitates an understanding of the true nature of pachychoroid diseases and AMD. The purpose of this review was to elucidate the relationship between pachychoroid diseases and AMD by interpreting previous findings on pachychoroid diseases and AMD from the novel viewpoints of genetic associations. We confirmed that previous genetic studies supported the concept of pachychoroid diseases. From a genetic viewpoint, the presence of thick choroid and the presence of choroidal vascular hyperpermeability were important characteristics of pachychoroid spectrum diseases. Previous studies have also suggested the classification of polypoidal choroidal vasculopathy (PCV) into two subtypes, pachychoroid neovasculopathy and drusen-driven PCV. Genetic viewpoints will be beneficial to rearrange subtypes of drusen-driven AMD and pachychoroid spectrum diseases. Further genetic studies are needed to investigate pachyvessels, pachydrusen and the significance of polypoidal lesions in pachychoroid neovasculopathy and drusen-driven AMD/PCV.

Incidence and risk factors for neovascular age-related macular degeneration in the fellow eye

PURPOSE

The epidemiology, risk factors, and the effect of anti-VEGF treatment on neovascular age-related macular degeneration (nAMD) have primarily been studied in the first eye developing the disease. The understanding of pathophysiology and planning of follow-up examinations can be improved by knowledge of incidence and risk factors for development of the disease in the fellow eye.

METHODS

In a prospective observational cohort study, epidemiological and clinical risk factors for the development of nAMD in the fellow eye among 2516 patients consecutively diagnosed with the disease from a population of 0.9 million citizens during a period of more than 10 years were studied.

RESULTS

nAMD had been diagnosed in the fellow eye of 541 (21.5%) of the patients. The incidence of fellow-eye involvement increased from approximately 5% in patients initially presenting with bilateral disease to approximately 28% more than 6 years after the diagnosis in the first eye. Visual acuity (VA) was higher and central retinal thickness (CRT) was lower in fellow eyes with nAMD diagnosed later than the first eye. Male gender, increasing leakage area, and peripapillary location of the subretinal neovascular membrane in the first eye reduced the risk of developing disease in the fellow eye.

CONCLUSIONS

The planning of follow-up examinations of patients diagnosed with nAMD in one eye should consider that the risk of fellow-eye involvement is higher within the first 6 years, in women, and when the leakage area in the first eye is small and not located peripapillary.

A genome-wide association study identified a novel genetic loci STON1-GTF2A1L/LHCGR/FSHR for bilaterality of neovascular age-related macular degeneration

Bilateral neovascular age-related macular degeneration (AMD) causes much more handicaps for patients than unilateral neovascular AMD. Although several AMD-susceptibility genes have been evaluated for their associations to bilaterality, genome-wide association study (GWAS) on bilaterality has been rarely reported. In the present study, we performed GWAS using neovascular AMD cases in East Asian. The discovery stage compared 581,252 single nucleotide polymorphisms (SNPs) between 803 unilateral and 321 bilateral Japanese cases but no SNP showed genome-wide significance, while SNPs at six regions showed P-value < 1.0 × 10⁻⁵, STON1-GTF2A1L/LHCGR/FSHR, PLXNA1, CTNNA3, ARMS2/HTRA1, LHFP, and FLJ38725. The first replication study for these six regions comparing 36 bilateral and 132 unilateral Japanese cases confirmed significant associations of rs4482537 (STON1-GTF2A1L/LHCGR/FSHR), rs2284665 (ARMS2/HTRA1), and rs8002574 (LHFP) to bilaterality. In the second replication study comparing 24 bilateral and 78 unilateral cases from Singapore, rs4482537 (STON1-GTF2A1L/LHCGR/FSHR) only showed significant association. Meta-analysis of discovery and replication studies confirmed genome-wide level significant association (P = 2.61 × 10⁻⁹) of rs4482537 (STON1-GTF2A1L/LHCGR/FSHR) and strong associations (P = 5.76 × 10⁻⁷ and 9.73 × 10⁻⁷, respectively) of rs2284665 (ARMS2/HTRA1) and rs8002574 (LHFP). Our GWAS for neovascular AMD bilaterality found new genetic loci STON1-GTF2A1L/LHCGR/FSHR and confirmed the previously reported association of ARMS2/HTRA1.

Association of LOC387715/ARMS2 (rs10490924) Gene Polymorphism with Age-Related Macular Degeneration in the Brazilian Population

BACKGROUND

An association between LOC387715/ARMS2 (rs10490924) gene polymorphism and AMD has been reported. The aim of this study was to evaluate whether this polymorphism is associated with AMD in a Brazilian cohort.

MATERIALS AND METHODS

In total, 126 unrelated AMD patients (mean age 74.17 ± 7.64) were compared with 86 healthy controls (mean age 71.82 ± 7.12). Study subjects were classified according to the International ARM Epidemiological Study Group definition for early and late-stage AMD. LOC387715/ARMS2 rs10490924 polymorphism was evaluated through polymerase chain reaction and direct sequencing.

RESULTS

The T allele frequency was significantly higher in AMD patients than in controls (39.6% compared to 20.3%). The odds ratio (OR) for AMD was 2.05 (95% CI 1.13-3.71) for heterozygotes (TG) and 8.32 (95% CI 2.30-45.99) for homozygotes (TT).

CONCLUSIONS

These results suggest that there is a contribution of the rs10490924 SNP of the LOC387715/ARMS2 gene to AMD susceptibility in this sample of the Brazilian population.

Prevalence and Genetic Characteristics of Geographic Atrophy among Elderly Japanese with Age-Related Macular Degeneration

Objective

To investigate the prevalence and genetic characteristics of geographic atrophy (GA) among elderly Japanese with advanced age-related macular degeneration (AMD) in a clinic-based study.

Methods

Two-hundred and ninety consecutive patients with advanced AMD were classified into typical neovascular AMD, polypoidal choroidal vasculopathy (PCV), retinal angiomatous proliferation (RAP) or geographic atrophy (GA). Genetic variants of ARMS2 A69S (rs10490924) and CFH I62V (rs800292) were genotyped using TaqMan Genotyping Assays. The clinical and genetic characteristics were compared between patients with and without GA.

Results

The number of patients diagnosed as having typical neovascular AMD, PCV, RAP and GA were 98 (33.8%), 151 (52.1%), 22 (7.5%) and 19 (6.6%), respectively. Of 19 patients with GA, 13 patients (68.4%) had unilateral GA with exudative AMD in the contralateral eye. Patients with GA were significantly older, with a higher prevalence of reticular pseudodrusen, bilateral involvement of advanced AMD and T-allele frequency of ARMS2 A69S compared with those with typical AMD and PCV; although there were no differences in the genetic and clinical characteristics among patients with GA and RAP.

Conclusions

The prevalence of GA was 6.6% among elderly Japanese with AMD. Patients with GA and RAP exhibited genetic and clinical similarities.

Association of familial macular degeneration with specific genetic markers: a case report

INTRODUCTION

Age-related macular degeneration is a serious visual disorder of the central retina and was recently reported to be associated with genetic background. Here we describe a genetic link to early onset age-related macular degeneration in members of an Asian family.

CASE PRESENTATION

A 73-year-old Asian woman developed age-related macular degeneration in the fifth decade of her life and her 49-year-old daughter developed age-related macular degeneration. Because of the family history and the early onset, family members were tested for two single nucleotide polymorphism variants (rs10490924 and rs11200638) at a recently identified susceptibility locus for age-related macular degeneration. Both alleles in the 73-year-old woman were of the high-risk variants (T/T for rs10490924 and A/A for rs11200638), and her two daughters and a grandson each carried the risk variants (T and A) one on each allele.

CONCLUSIONS

In a case where multiple family members had early onset age-related macular degeneration, we found two high-risk single nucleotide polymorphism variants in the age-related macular degeneration susceptibility locus, suggesting the combination of the known single nucleotide polymorphism variants as a potent age-related macular degeneration diagnostic indicator.

MMP20 and ARMS2/HTRA1 Are Associated with Neovascular Lesion Size in Age-Related Macular Degeneration

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of severe visual impairment. Despite treatment, a central scotoma often remains. The size of the scotoma depends on the lesion size of the choroidal neovascular membrane and significantly affects the patient's quality of life, and the lesion size of neovascularization also affects response to treatments. The aim of this study was to identify genes associated with the neovascular lesion size in neovascular AMD.

DESIGN

A genome-wide association study (GWAS).

PARTICIPANTS

We included 1146 Japanese patients with neovascular AMD.

METHODS

We performed a 2-stage GWAS for the lesion size of AMD as a quantitative trait among 1146 (first stage: 727, second stage: 419) Japanese patients with neovascular AMD. Lesion size was determined by the greatest linear dimension measured with fluorescein angiography examination before treatment. We examined the association between the genotypic distribution of each single nucleotide polymorphism (SNP) and the trait using an additive model adjusted for age and sex. To evaluate the associations between AMD development and SNPs associated with lesion size, we also performed a case-control study by using the genotype data from these 1146 Japanese patients as case subjects and the fixed dataset from the Nagahama Study as control subjects.

MAIN OUTCOME MEASURES

Genes associated with the lesion size in neovascular AMD.

RESULTS

In the discovery stage, rs10895322 in MMP20 showed a genome-wide significant P value of 6.95×10(-8), and rs2284665 in ARMS2/HTRA1 showed a P value of 1.55×10(-7). The associations of these 2 SNPs were successfully replicated in the replication stage, and a meta-analysis of both stages showed genome-wide significant P values (2.80×10(-9) and 4.41×10(-9), respectively). In a case-control study using 3248 Japanese subjects as controls, we could not find contribution of MMP20 rs10895322 for AMD development. Although MMP20 has been thought to be expressed only in dental tissues, we confirmed MMP20 expression in the human retina and retinal pigment epithelium/choroid with polymerase chain reaction.

CONCLUSIONS

The growth of choroidal neovascularization in AMD would be affected by 2 genes: MMP20, a newly confirmed gene expressed in the retina, and ARMS2/HTRA1, a well-known susceptibility gene for AMD.

The Clinical Effectiveness and Cost-Effectiveness of Screening for Age-Related Macular Degeneration in Japan: A Markov Modeling Study

OBJECTIVE

To investigate the cost-effectiveness of screening and subsequent intervention for age-related macular degeneration (AMD) in Japan.

METHODS

The clinical effectiveness and cost-effectiveness of screening and subsequent intervention for AMD were assessed using a Markov model. The Markov model simulation began at the age of 40 years and concluded at the age of 90 years. The first-eye and second-eye combined model assumed an annual state-transition probability, development of prodromal symptoms, choroidal neovascularization (CNV), and reduction in visual acuity. Anti-vascular-endothelial-growth-factor (anti-VEGF) intravitreal injection therapy and photodynamic therapy (PDT) were performed to treat CNV. Intake of supplements was recommended to patients who had prodromal symptoms and unilateral AMD. Data on prevalence, morbidity, transition probability, utility value of each AMD patient, and treatment costs were obtained from published clinical reports.

RESULTS

In the base-case analysis, screening for AMD every 5 years, beginning at the age of 50 years, showed a decrease of 41% in the total number of blind patients. The screening program reduced the incidence of blindness more than did the additional intake of supplements. However, the incremental cost-effectiveness ratio (ICER) of screening versus no screening was 27,486,352 Japanese yen (JPY), or 259,942 US dollars (USD) per quality-adjusted life year (QALY). In the sensitivity analysis, prodromal symptom-related factors for AMD had great impacts on the cost-effectiveness of screening. The lowest ICER obtained from the best scenario was 4,913,717 JPY (46,470 USD) per QALY, which was approximately equal to the willingness to pay in Japan.

CONCLUSIONS

Ophthalmologic screening for AMD in adults is highly effective in reducing the number of patients with blindness but not cost-effective as demonstrated by a Markov model based on clinical data from Japan.

Association of Genetic Variants with Polypoidal Choroidal Vasculopathy: A Systematic Review and Updated Meta-analysis

TOPIC

A systematic review and meta-analysis of the genetic association with polypoidal choroidal vasculopathy (PCV) and the genetic difference between PCV and neovascular age-related macular degeneration (nAMD).

CLINICAL RELEVANCE

To identify genetic biomarkers that are potentially useful for genetic diagnosis of PCV and for differentiating PCV from nAMD.

METHODS

We performed a literature search in EMBASE, PubMed, Web of Science, and the Chinese Biomedical Database for PCV genetic studies published before February 6, 2015. We then conducted a meta-analysis of all polymorphisms that had sufficient genotype/allele data reported in ≥2 studies and estimated the summary odds ratio (OR) and 95% confidence intervals (CIs) for PCV. We also compared the association profiles between PCV and nAMD, and performed a sensitivity analysis.

RESULTS

A total of 66 studies were included in the meta-analysis, involving 56 polymorphisms in 19 genes/loci. In total, 31 polymorphisms in 10 genes/loci (age-related maculopathy susceptibility 2 [ARMS2], high-temperature requirement factor A1 [HTRA1], complement factor H [CFH], complement component 2 [C2], CFB, RDBP, SKIV2L, CETP, 8p21, and 4q12) were significantly associated with PCV. Another 25 polymorphisms in 13 genes (ARMS2, HTRA1, C2, CFB, ELN, LIPC, LPL, ABCA1, VEGF-A, TLR3, LOXL1, SERPING1, and PEDF) had no significant association. Twelve polymorphisms at the ARMS2-HTRA1 locus showed significant differences between PCV and nAMD. The sensitivity analysis validated the significance of our analysis.

CONCLUSIONS

This study revealed 31 polymorphisms in 10 genes/loci that contribute to PCV susceptibility. Among them, ARMS2-HTRA1 also showed allelic diversity between PCV and nAMD. Our results confirm the gene variants that could affect the phenotypic expressions of PCV and nAMD.

Rare genetic variants in Tunisian Jewish patients suffering from age-related macular degeneration

PURPOSE

To explore the molecular basis of familial, early onset, age-related macular degeneration (AMD) with diverse phenotypes, using whole exome sequencing (WES).

METHODS

We performed WES on four patients (two sibs from two families) manifesting early-onset AMD and searched for disease-causing genetic variants in previously identified macular degeneration related genes. Validation studies of the variants included bioinformatics tools, segregation analysis of mutations within the families and mutation screening in an AMD cohort of patients.

RESULTS

The index patients were in their 50s when diagnosed and displayed a wide variety of clinical AMD presentations: from limited drusen in the posterior pole to multiple basal-laminar drusen extending peripherally. Severe visual impairment due to extensive geographic atrophy and/or choroidal-neovascularisation was common by the age of 75 years. Approximately, 400 000 genomic variants for each DNA sample were included in the downstream bioinformatics analysis, which ended in the discovery of two novel variants; in one family a single bp deletion was identified in the Hemicentin (HMCN1) gene (c.4162delC), whereas in the other, a missense variant (p.V412M) in the Complement Factor-I (CFI) gene was found. Screening for these variants in a cohort of patients with AMD identified another family with the CFI variant.

CONCLUSIONS

This report uses WES to uncover rare genetic variants in AMD. A null-variant in HMCN1 has been identified in one AMD family, and a missense variant in CFI was discovered in two other families. These variants confirm the genetic complexity and significance of rare genetic variants in the pathogenesis of AMD.

Incidence of choroidal neovascularization in the fellow eye in the comparison of age-related macular degeneration treatments trials

OBJECTIVE

To assess the influence of drug; dosing regimen; and traditional, nontraditional, and genetic risk factors on the incidence of choroidal neovascularization (CNV) in the fellow eye of patients treated for CNV with ranibizumab or bevacizumab.

DESIGN

Cohort study of patients enrolled in a multicenter, randomized clinical trial.

PARTICIPANTS

Patients with no CNV in the fellow eye at the time of enrollment in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

METHODS

Eligibility criteria for the clinical trial required that study eyes have evidence on fluorescein angiography and optical coherence tomography of CNV secondary to age-related macular degeneration (AMD) and visual acuity between 20/25 and 20/320. Treatment for the study eye was assigned randomly to either ranibizumab or bevacizumab and to 3 different regimens for dosing over a 2-year period. The genotypes for 4 single nucleotide polymorphisms (SNPs) associated with risk of AMD were determined. Only patients without CNV in the fellow eye at baseline were considered at risk. The CATT ophthalmologists examined patients every 4 weeks through 2 years and recorded treatment for CNV in the fellow eye.

MAIN OUTCOME MEASURES

Development of CNV in the fellow eye.

RESULTS

Among 1185 CATT participants, 727 (61%) had no CNV in the fellow eye at enrollment. At 2 years, CNV had developed in 75 (20.6%) of 365 patients treated with ranibizumab and in 60 (16.6%) of 362 patients treated with bevacizumab (absolute difference, 4.0%; 95% confidence interval [CI], -1.7% to 9.6%; P = 0.17). The risk ratio for pro re nata dosing relative to monthly dosing was 1.1 (95% CI, 0.8-1.6). Greater elevation of the retinal pigment epithelium and fluid in the foveal center of the study eye were associated with increased incidence of CNV in the fellow eye. Incidence was not associated with genotype on rs1061170 (CFH), rs10490924 (ARMS2), rs11200638 (HTRA1), and rs2230199 (C3; P>0.35).

CONCLUSIONS

Through 2 years, there was no statistically significant difference between ranibizumab and bevacizumab in incidence of CNV in the fellow eye. Genotype on 4 SNPs previously found to be associated with AMD did not affect the risk of CNV in the fellow eye among CATT patients.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.