Study of New Mutations in Cone Disorders | NCT04658251

Studies
Study of New Mutations in Cone Disorders

NCT04658251

Sponsor

University Hospital, Lille

Status

Terminated

Last Update Posted

May 22, 2026Actual

Enrollment

7Actual

Phase

Not provided

Conditions

Retinal Dystrophy, Cone-Rod
Cone Dystrophy
Cone Rod Dystrophy
Macular Degeneration

Interventions

Blood and/or skin biopsy

Countries

France

Protocol Section

Identification Module Status Module Sponsor/Collaborators Module Oversight Module Description Module Conditions Module Design Module Arms/Interventions Module Outcomes Module Eligibility Module Contacts/Locations Module References Module IPD Sharing Statement Module

Results Section

Participant Flow Module Baseline Characteristics Module Outcome Measures Module Adverse Events Module More Info Module

Annotation Section

Annotation Module

Document Section

Large Document Module

Derived Section

Miscellaneous Info Module Condition Browse Module Intervention Browse Module

Protocol Section

Identification Module

NCT ID

Results Section

No data available

No data is available for this block.

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Version Holder

ID	Type	Description	Link
2020-A02559-30	Other Identifier	ID-RCB number,ANSM

Status Module

Record Verification Date

May 2026

Overall Recruitment Status or Expanded Access Status

Terminated

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

End of COVID

Expanded Access Info

Start Date

Mar 3, 2021Actual

Primary Completion Date

Apr 14, 2024Actual

Completion Date

Apr 14, 2024Actual

First Submitted Date

Dec 1, 2020

First Submission Date that Met QC Criteria

Dec 7, 2020

First Posted Date

Dec 8, 2020Actual

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

May 20, 2026

Last Update Posted Date

May 22, 2026Actual

Oversight Module

Has Data Monitoring Committee (DMC)

Is FDA Regulated Drug

Is FDA Regulated Device

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

Brief Summary

High throughput sequencing gives the opportunity to improve the genetic diagnosis for patients suffering from retinal dystrophies and specially from cone disorders. However, a large number of mutations are identified, mostly in introns of the genes, and in silico analysis are not sufficient to assign the pathogenicity of these mutations, without which the diagnosis confirmation cannot be done. For that purpose, a functional analysis of intronic variants of unknown significance detected in patients, with minigene splice assays in parallel with the analysis of the effect of the variant on splicing directly in the cells of the patient, by analyzing the RNA from leucocytes, fibroblasts, lymphoblastoïd cells or precursor of photoreceptor cells, which is the only proof of pathogenicity for variants

Detailed Description

Not provided

Design Module

Study Type

Observational

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Target Follow-Up Duration

Not provided

Phases

Not provided

Interventional Study Design

Allocation

Not provided

Intervention Model

Biospecimen

Retention

Enrollment

7Actual

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
Patients with an intronic variant unknown in a gene implicated in cone disorders.			Genetic: Blood and/or skin biopsy

Interventions

Name	Type	Description	Arm Group Labels	Other Names
Blood and/or skin biopsy	Genetic	Blood and/or skin biopsy will be withdrawn, for RNA extraction in order to test the effect of the variant on splicing.	Patients with an intronic variant unknown in a gene implicated in cone disorders.

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Effect of the intronic variant on RNA splicing observed in cellulo and/or on patient cells,	Analysis of RNA transcripts of the gene carrying a variant of unknown significance.	at 2 years

Secondary Outcomes

Measure	Description	Time Frame
Effect of the intronic variant on RNA by Minigene splice assay in transient cell cultures		at 2 years
Effect of the intronic variant on RNA by analysis of patient RNA transcripts		at 2 years

Other Outcomes

Not provided

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

clinical diagnosis of cone disorder
identification of a variant of unknown significance
possibility of samplings
informed consent

Exclusion Criteria:

no variant of unknown significance identified
no informed consent

Accepts Healthy Volunteers

Sex

All

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

3 Years

Maximum Age

Not provided

Standard Ages

ChildAdultOlder Adult

Study Population

Patients carrying an intronic variant of unknown significance (or carrying an exonic variant with a predicted effect on splicing) in a gene implicated (or potentially implicated) in cone disorders, will be included in the study.

Sampling Method

Non-Probability Sample

Contacts/Locations Module

Central Contacts

Not provided

Overall Officials

Name	Affiliation	Role
Claire-Marie DHAENENS, MD	University Hospital, Lille	Principal Investigator

Locations

Facility	Status	City	State	ZIP	Country	Contacts
CHU lille		Lille		59037	France

Condition Browse Module

MeSH Terms

ID	Term
D000071700	Cone-Rod Dystrophies
D000077765	Cone Dystrophy
D008268	Macular Degeneration
D058499	Retinal Dystrophies

Ancestor Terms

ID	Term
D015785	Eye Diseases, Hereditary
D005128	Eye Diseases
D012162	Retinal Degeneration
D012164	Retinal Diseases

Browse Leaves

Not provided

Browse Branches

Not provided

Description

Blood samples:

Paxgen tubes (2 x 5ml) and heparin tubes (2 x 7ml) will be collected (maximum 32 ml) for RNA extraction if the candidate gene is expressed in the leucocytes
Potentially 2 Vacutainer CPT tubes for IPSC generation

Biopsy:

Potentially a skin biopsy (3 mm diameter) will be carried out if the gene is not expressed in leucocytes