Objective To examine if the genes encoding the pleckstrin homology domainCcontaining protein gene (PLEKHA1), hypothetical gene, and HtrA serine peptidase 1 gene (SNP rs2293870, not part of the significant haplotypes containing rs10490924 and rs11200638, showed as strong an association with increased susceptibility to neovascular AMD. majority of debilitating vision loss due to AMD. In the United States, it is predicted that about 3 million individuals over the age Rabbit Polyclonal to VN1R5 of 50 will have advanced AMD in at least one eye by 2020.1 Current diagnostic methods focus on the detection of neovascular AMD, because available treatments are directed against this advanced stage of the disease. 95635-55-5 Although the newest treatments offer some chance of visual improvement, they require invasive delivery methods, cannot prevent disease, and have limited ability to reverse vision loss. Assessments of an individuals risk of developing advanced AMD are based on ocular findings in those who already have the early stages. Methods have yet to be discovered that determine which individuals are at highest risk of vision loss due to AMD prior to the development of any signs of the disease. The identification of genetic variants that could be used as biomarkers would help to predict risk of the more advanced stages of AMD. Moreover, discovering precisely which genes and environmental factors contribute to the pathophysiology of AMD and elucidating their modes of interaction could provide new targets for therapeutic or behavioral intervention, thereby reducing or preventing the incidence of this disease. Although the complement factor H gene (gene, and HtrA serine peptidase 1 gene (gene is associated with all types of AMD,8C11 it was recently shown that the single-nucleotide polymorphism (SNP) rs11200638 in the promoter, in linkage disequilibrium (LD) with rs10490924, is likely the causal variant.12C14 Moreover, data from the Age-Related Eye Disease Study showed a significant association between the SNP rs1045216 in and increased risk of neovascular AMD.11 Table 1 Location of Microsatellite Markers and Single-Nucleotide Polymorphisms (SNPs) In the study presented here, we genotyped 33 megabases 95635-55-5 of the 10q26 region (Table 1) in samples from unrelated patients with neovascular AMD who had one sibling with normal maculae and was past the age at which the affected sibling was diagnosed with neovascular AMD. Our phenotypically well-defined cohort of 268 subjects comprised 134 extremely discordant sibpairsthat is, pairs with one member in the upper 10% of disease severity (affected sibling) and the other member in the bottom 10% to 30% of disease severity (unaffected sibling).15,16 We have previously demonstrated that such types of sibpairs can be powerful in identifying the contribution that genes and environmental factors make simultaneously to AMD susceptibility.17 We sought to validate previous findings and possibly identify novel variants in the 10q26 region using a combination of direct sequencing and analysis of highly polymorphic microsatellite markers tightly linked to the genes of interest. For each subject, we directly sequenced exon 12 of to identify the contribution that allelic risk factors such as those reported in the 10q26 region make independently and in combination with the factors most consistently associated with AMD susceptibility, Y402H genotype2C6,18 and smoking.19 Materials and 95635-55-5 Methods Patient Population The protocol was reviewed and approved by the institutional review boards at the Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, and William Beaumont Hospital, Royal Oak, Michigan, and conforms to the tenets of the Declaration of Helsinki. Eligible patients were enrolled in this study after they gave informed consent in person, over the phone, or through the mail before answering a standardized questionnaire and donating 10 to 50 ml of venous blood. In most cases, the donation of venous blood from both patients and their siblings was made on the same day that fundus photographs and/or fluorescein angiographs were obtained. Details of the recruitment of patients and their siblings are described elsewhere.20 In brief, index patients with neovascular AMD were recruited from the Retina Service of the Massachusetts Eye and Ear Infirmary and Associated Retina Consultants at the Beaumont Hospital. All index patients were 50 years or older and had the neovascular form of AMD in at least one eye, defined by subretinal hemorrhage, fibrosis, or fluorescein angiographic presence of neovascularization documented at the time of or before enrollment in the study. Patients whose only exudative finding was a retinal pigment epithelium detachment were excluded because this finding may not represent definite neovascular AMD and, therefore, the severe phenotype we sought. Patients with signs of.