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Identification of Genomic Loci Determining Susceptibility to the Development of High Myopia (ASSOMYP)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02583620
Recruitment Status : Completed
First Posted : October 22, 2015
Last Update Posted : October 22, 2015
Information provided by (Responsible Party):
University Hospital, Toulouse

Brief Summary:
Compelling evidence of genetic components in high myopia has been put forward by several studies. Twin cohorts, familial linkage studies and population studies has described at least 10 loci containing genes involved in the disease development. The investigators previously demonstrated novel linkage on chromosome 7q36 and chromosome 7p15 in French families. A new approach consisting of a case-control based population association study is underway in order to recover a high number of myopic subjects avoiding the limitation of familial cases. 1.8 millions polymorphic markers will be compared with emmetropic controls in order to recover loci associated with the disease in the population.

Condition or disease Intervention/treatment Phase
Myopia Genetic: blood sample Not Applicable

Detailed Description:

Myopia is a worldwide refractive ocular disorder and is the most frequent visual defect in man. It is responsible for a major health problem, affecting around 25% of the western population. High myopia is the most severe form of the myopic spectrum and is defined by an increase of refractive error beyond -5 dioptres. About 2.5% of the general population suffers from this, while the secondary complications are responsible among these patients for the 4th cause of legal blindness. The physiopathology of myopia remains unknown and mechanisms leading to the disease are most probably complex, mixing acquired environmental and genetics factors. Our team in a previous study gathered and analysed an important series of high myopic families: Heritability, segregation and linkage analyses modelling the transmission mode localised two major genomic regions linked to high myopia susceptibility on chromosome 7q36 and chromosome 7p15. Several loci have been described by other teams working on the same topic among different human populations. Very recently reappraisal of 55 families led to the delineation of a complex segregation model of the high myopia phenotype thus claiming an oligo- polygenic mode of transmission. Together these results express the need to collect more cases and to substitute an linkage studies by association studies already conducted in order to increase the power to detect involved loci.

To find one or more genomic loci involved in high myopia susceptibility; a polygenic model and association analysis is considered a referent method to decipher the participation of multiple, low acting loci. High density SNPs/CNVs DNA markers covering the whole genome will be used for genotyping.

Phenotypes including ophthalmologic evaluation, ethno-geographic origin and familial data will be collected in order to allow further stratification or clustering.

Computing of the statistical power of the association analysis conducted to minimize the number of false positive associations and to obtain a 80% of detection power indicated the need of 400 high myopic subjects and 400 controls to be analysed.

Collaboration between a Clinical Investigation Center (CIC) and Ophthalmology clinics will be used to overcome recruitment problems. DNA extraction and genotyping will be conducted in Institut national de la santé et de la recherche (INSERM-UPS) unit in Toulouse using the "Toulouse's Génopole" microarrays genotyping facilities.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 553 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Identification of Genomic Loci Determining Susceptibility to the Development of High Myopia
Study Start Date : September 2009
Actual Primary Completion Date : September 2014
Actual Study Completion Date : September 2014

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Emmetropic volunteers
Blood sample
Genetic: blood sample
A blood test is realized on the subject

High myopic volunteers
Blood sample
Genetic: blood sample
A blood test is realized on the subject

Primary Outcome Measures :
  1. Numbers of allele frequencies at markers in the population [ Time Frame: Baseline ]
    Numbers of allele frequencies at markers in the population

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • high myopic (cases) volunteers,
  • emmetropic (controls) volunteers

Exclusion Criteria:

  • syndromic myopic children under 18 years,
  • non autonomous adults

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02583620

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CHU Pointe-à-Pitre
Pointe-à-Pitre, Guadeloupe, France, 97139
CHU Bordeaux Hôpital Pellegrin
Bordeaux, France, 33076
CHU Limoges Hôpital Dupuytren
Limoges, France, 87042
CHU Toulouse Hôpital Purpan
Toulouse, France, 31059
Sponsors and Collaborators
University Hospital, Toulouse
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Principal Investigator: François MALECAZE, PhD, MD University Hospital, Toulouse

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Responsible Party: University Hospital, Toulouse Identifier: NCT02583620     History of Changes
Other Study ID Numbers: 09 036 08
First Posted: October 22, 2015    Key Record Dates
Last Update Posted: October 22, 2015
Last Verified: October 2015

Keywords provided by University Hospital, Toulouse:
high myopia

Additional relevant MeSH terms:
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Disease Susceptibility
Refractive Errors
Eye Diseases
Disease Attributes
Pathologic Processes