title: Reduced secretion of fibulin 5 in age-related macular degeneration and cutis laxa.
abstract: Age-related macular degeneration (ARMD) is the leading cause of irreversible visual loss in the Western world, affecting approximately 25 million people worldwide. The pathogenesis is complex and missense mutations in FBLN5 have been reported in association with ARMD. We have investigated the role of fibulin 5 in ARMD by completing the first European study of the gene FBLN5 in ARMD (using 2 European cohorts of 805 ARMD patients and 279 controls) and by determining the functional effects of the missense mutations on fibulin 5 expression. We also correlated the FBLN5 genotype with the ARMD phenotype. We found two novel sequence changes in ARMD patients that were absent in controls and expressed these and the other nine reported FBLN5 mutations associated with ARMD and two associated with the autosomal recessive disease cutis laxa. Fibulin 5 secretion was significantly reduced (P<0.001) for four ARMD (p.G412E, p.G267S, p.I169 T, and p.Q124P) and two cutis laxa (p.S227P, p.C217R) mutations. These results suggest that some missense mutations associated with ARMD lead to decreased fibulin 5 secretion with a possible corresponding reduction in elastinogenesis. This study confirms the previous work identifying an association between FBLN5 mutations and ARMD and for the first time suggests a functional mechanism by which these mutations can lead to ARMD. It further demonstrates that FBLN5 mutations can be associated with different phenotypes of ARMD (not limited to the previously described cuticular drusen type). Such knowledge may ultimately lead to the development of novel therapies for this common disease.
authors.affiliation: Human Genetics Division, University of Southampton, Southampton, Hampshire, United Kingdom. a.j.lotery@soton.ac.uk
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lotery
authors.forename: Dominique
authors.initials: D
authors.lastname: Baas
authors.forename: Caroline
authors.initials: C
authors.lastname: Ridley
authors.forename: Richard P O
authors.initials: RP
authors.lastname: Jones
authors.forename: Caroline C W
authors.initials: CC
authors.lastname: Klaver
authors.forename: Edwin
authors.initials: E
authors.lastname: Stone
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nakamura
authors.forename: Andrew
authors.initials: A
authors.lastname: Luff
authors.forename: Helen
authors.initials: H
authors.lastname: Griffiths
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Arthur A B
authors.initials: AA
authors.lastname: Bergen
authors.forename: Dorothy
authors.initials: D
authors.lastname: Trump
mesh_terms: D000367:Age Factors; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D015331:Cohort Studies; D003483:Cutis Laxa / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D020125:Mutation, Missense; D010641:Phenotype; D017510:Protein Folding; D011859:Radiography; D012160:Retina / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D016326:Extracellular Matrix Proteins; C492373:FBLN5 protein, human