Publications by authors named "Louise M Downey"

Background: Neovascular age-related macular degeneration (nAMD) presents a significant treatment burden for patients, carers and medical retina services. However, significant debate remains regarding how best to manage nAMD when assessing disease activity by optical coherence tomography (OCT), and particularly the significance of different types of fluid and how the understanding of anatomical efficacy can influence treatment strategies. This article provides opinion on the practical implications of anatomical efficacy and significance of fluid in the management of nAMD and proposes recommendations for healthcare professionals (HCPs) to improve understanding and promote best practice to achieve disease control.

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Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder characterized by the abnormal development of the retinal vasculature. The majority of mutations identified in FEVR are found within four genes that encode the receptor complex (FZD4, LRP5, and TSPAN12) and ligand (NDP) of a molecular pathway that controls angiogenesis, the Norrin-β-catenin signaling pathway. However, half of all FEVR-affected case subjects do not harbor mutations in these genes, indicating that further mutated genes remain to be identified.

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Purpose: Familial exudative vitreoretinopathy (FEVR) is an inherited disorder that disrupts the development of the retinal vasculature and can result in blindness. FEVR is genetically heterogeneous and mutations in four genes, NDP, FZD4, LRP5, and TSPAN12, encoding components of a novel ligand-receptor complex that activates the Norrin-β-catenin signaling pathway, account for approximately 50% of cases. We recently identified mutations in TSPAN12 as a cause of dominant FEVR.

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Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder of the retinal vascular system. Although mutations in three genes (LRP5, FZD4, and NDP) are known to cause FEVR, these account for only a fraction of FEVR cases. The proteins encoded by these FEVR genes form part of a signaling complex that activates the Norrin-beta-catenin signaling pathway.

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Purpose: To describe a patient with DiGeorge syndrome in association with familial exudative vitreoretinopathy (FEVR).

Design: Observational case report.

Participants: A newborn female and her parents.

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The combination of recessively inherited cone-rod dystrophy (CRD) and amelogenesis imperfecta (AI) was first reported by Jalili and Smith in 1988 in a family subsequently linked to a locus on chromosome 2q11, and it has since been reported in a second small family. We have identified five further ethnically diverse families cosegregating CRD and AI. Phenotypic characterization of teeth and visual function in the published and new families reveals a consistent syndrome in all seven families, and all link or are consistent with linkage to 2q11, confirming the existence of a genetically homogenous condition that we now propose to call Jalili syndrome.

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Purpose: Mutations in the frizzled-4 gene (FZD4) have recently been associated with autosomal dominant familial exudative vitreoretinopathy (FEVR) in families linking to the EVR1 locus on the long arm of chromosome 11. The purpose of this study was to screen FZD4 in a panel of 40 patients with FEVR to identify the types and location of mutations and to calculate what proportion of this heterogeneous condition is attributable to FZD4 mutations.

Methods: PCR products were generated from genomic DNA with primers designed to amplify the coding sequence of FZD4.

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Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder of the retinal vascular system. Autosomal dominant FEVR is genetically heterogeneous, but its principal locus, EVR1, is on chromosome 11q13-q23. The gene encoding the Wnt receptor frizzled-4 (FZD4) was recently reported to be the EVR1 gene, but our mutation screen revealed fewer patients harboring mutations than expected.

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Purpose: Familial exudative vitreoretinopathy (FEVR) is a genetically heterogeneous inherited blinding disorder of the retinal vascular system. To date three loci have been mapped: EVR1 on chromosome 11q, EVR2 on chromosome Xp, and EVR3 on chromosome 11p. The gene underlying EVR3 remains unidentified whilst the EVR2 gene, which encodes the Norrie disease protein (NDP), was identified over a decade ago.

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Purpose: To identify the locus responsible for rge (retinopathy globe enlarged) in chickens and further characterise the rge phenotype.

Methods: A colony of chickens carrying the rge mutation was rederived from a single heterozygous animal of the original line. The eyes of blind, heterozygous and normal birds were subjected to ophthalmic, morphometric and histopathological examination to confirm and extend published observations.

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Article Synopsis
  • The study aims to identify the genetic location of the rdd mutation causing blindness in chickens, and to further understand the related visual impairment symptoms.
  • Through various examinations including ophthalmic and genetic mapping techniques, the researchers observed that rdd homozygotes exhibit significant vision loss, with morphological abnormalities developing as they age.
  • The findings indicate that the rdd mutation is sex-linked and mapped to a specific region of the chicken Z chromosome, which is similar to regions associated with human retinitis pigmentosa, suggesting potential candidate genes involved in the disease.
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A consanguineous Arab pedigree in which recessive amelogenesis imperfecta (AI) and cone-rod dystrophy cosegregate, was screened for linkage to known retinal dystrophy and tooth abnormality loci by genotyping neighbouring microsatellite markers. This analysis resulted in linkage with a maximum lod score of 7.03 to the marker D2S2187 at the achromatopsia locus on chromosome 2q11, and haplotype analysis placed the gene(s) involved in a 2 cM/5 Mb interval between markers D2S2209 and D2S373.

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