title: FLT1 genetic variation predisposes to neovascular AMD in ethnically diverse populations and alters systemic FLT1 expression.
abstract: OBJECTIVE
  Current understanding of the genetic risk factors for age-related macular degeneration (AMD) is not sufficiently predictive of the clinical course. The VEGF pathway is a key therapeutic target for treatment of neovascular AMD; however, risk attributable to genetic variation within pathway genes is unclear. We sought to identify single nucleotide polymorphisms (SNPs) associated with AMD within the VEGF pathway.
  
  
  METHODS
  Using a tagSNP, direct sequencing and meta-analysis approach within four ethnically diverse cohorts, we identified genetic risk present in FLT1, though not within other VEGF pathway genes KDR, VEGFA, or VASH1. We used ChIP and ELISA in functional analysis.
  
  
  RESULTS
  The FLT1 SNPs rs9943922, rs9508034, rs2281827, rs7324510, and rs9513115 were significantly associated with increased risk of neovascular AMD. Each association was more significant after meta-analysis than in any one of the four cohorts. All associations were novel, within noncoding regions of FLT1 that do not tag for coding variants in linkage disequilibrium. Analysis of soluble FLT1 demonstrated higher expression in unaffected individuals homozygous for the FLT1 risk alleles rs9943922 (P = 0.0086) and rs7324510 (P = 0.0057). In silico analysis suggests that these variants change predicted splice sites and RNA secondary structure, and have been identified in other neovascular pathologies. These data were supported further by murine chromatin immunoprecipitation demonstrating that FLT1 is a target of Nr2e3, a nuclear receptor gene implicated in regulating an AMD pathway.
  
  
  CONCLUSIONS
  Although exact variant functions are not known, these data demonstrate relevancy across ethnically diverse genetic backgrounds within our study and, therefore, hold potential for global efficacy.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Leah A
authors.initials: LA
authors.lastname: Owen
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Margaux A
authors.initials: MA
authors.lastname: Morrison
authors.affiliation: Department of Ophthalmology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Jeeyun
authors.initials: J
authors.lastname: Ahn
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seoungnam, Republic of Korea.
authors.forename: Se Joon
authors.initials: SJ
authors.lastname: Woo
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Rosann
authors.initials: R
authors.lastname: Robinson
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Morgan
authors.affiliation: Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece.
authors.forename: Fani
authors.initials: F
authors.lastname: Zacharaki
authors.affiliation: Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Marina
authors.initials: M
authors.lastname: Simeonova
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Hironori
authors.initials: H
authors.lastname: Uehara
authors.affiliation: Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom.
authors.forename: Usha
authors.initials: U
authors.lastname: Chakravarthy
authors.affiliation: Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Hogg
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Balamurali K
authors.initials: BK
authors.lastname: Ambati
authors.affiliation: Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Kotoula
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baehr
authors.affiliation: Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Neena B
authors.initials: NB
authors.lastname: Haider
authors.affiliation: Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Silvestri
authors.affiliation: Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Joan W
authors.initials: JW
authors.lastname: Miller
authors.affiliation: Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece.
authors.forename: Evangelia E
authors.initials: EE
authors.lastname: Tsironi
authors.affiliation: Departments of Medicine (Biomedical Genetics), Ophthalmology, Neurology, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, Massachusetts, United States.
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Farrer
authors.affiliation: Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Ivana K
authors.initials: IK
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Kyu Hyung
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States.
authors.forename: Margaret M
authors.initials: MM
authors.lastname: DeAngelis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005006:Ethnicity; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006115:Greece / Q000208:ethnology; D006801:Humans; D047468:Immunoprecipitation; D008268:Macular Degeneration / Q000208:ethnology / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D011110:Polymorphism, Genetic; D015995:Prevalence; D012313:RNA / Q000235:genetics*; D056910:Republic of Korea / Q000208:ethnology; D015861:Retinal Neovascularization / Q000208:ethnology / Q000235:genetics* / Q000378:metabolism; D012307:Risk Factors; D006113:United Kingdom / Q000208:ethnology; D014481:United States / Q000453:epidemiology; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics* / Q000378:metabolism
chemical_list: D012313:RNA; C501162:FLT1 protein, human; C501163:Flt1 protein, mouse; D040281:Vascular Endothelial Growth Factor Receptor-1
keywords: FLT1; VEGF; age-related macular degeneration; angiogenesis