Modifying Factors in Striated Muscle Laminopathies (LMNAModifier)

Identification of Genetic Modifying Factors in Striated Muscle Laminopathies

Mutations in the LMNA gene, which codes for lamins A and C, proteins of the nuclear lamina, are responsible for a wide spectrum of pathologies, including a group specifically affecting striated skeletal and cardiac muscles, with cardiac involvement being life-threatening. At the skeletal muscle level, a wide phenotypic spectrum has been described, ranging from severe forms of congenital muscular dystrophy to less severe forms of limb-girdle muscular dystrophy. The great clinical variability of striated muscle laminopathies, both inter- and intra-familial, can be observed in the age of onset, severity of signs and progression of muscle and heart involvement. To date, more than 400 LMNA mutations have been associated with striated muscle laminopathies (www.umd.be/LMNA/), highlighting strong clinical and genetic heterogeneity. A few recurrent mutations linked to a difference in severity have been identified. However, these genotype-phenotype relationships and the rare cases of digenism reported do not explain all the clinical variability of laminopathies. Therefore, there are probably other factors of severity than the causative mutation, called "modifier genes".

Identification of such modifier genes has been initiated by studying a large family with significant clinical variability in the age of onset of muscle signs. A segregation analysis within this family identified 2 potential modifier loci. High-throughput sequencing restricted to these 2 regions according to phenotypic subgroups did not led to meaningful results so far. In addition, an international retrospective study of the natural history of early muscle laminopathies has allowed the investigators to highlight a strong inter-family clinical variability in patients carrying recurrent mutations. The investigators thus have strong preliminary data that could allow them to identify modifying genetic factors in a cohort of patients carrying a mutation in the LMNA gene.

In order to identify these factors that modulate the clinical severity of laminopathies, the investigators wish to collect biological material (muscle and/or skin biopsies) from patients carrying a mutation in the LMNA gene. The study of this biological material using multi OMICs technics will allow the investigators to identify and functionally validate the action of these modifying genes.

OMIICs is a set of techniques for characterising biological molecules using high-throughput approaches such as DNA sequencing, RNA sequencing and/or chromatin conformation (ATACseq...), proteins.

Study Overview

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Auvergne-Rhône-Alpes
    • France
      • Paris, France, France, 75013
        • Recruiting
        • Centre de référence maladies neuromusculaires, Institut de myologie, Hôpital Pitié-Salpêtrière
        • Contact:
        • Contact:
    • Hérault
      • Montpellier, Hérault, France, 34295
        • Not yet recruiting
        • Service de Neuropédiatrie, Centre de Référence Maladies Neuromusculaires, CHU de Montpellier
        • Contact:
    • Ille-et-Vilaine
      • Rennes, Ille-et-Vilaine, France, 35000
        • Not yet recruiting
        • Service de Génétique médicale, CHU Rennes
        • Contact:
    • Loire-Atlantique
      • Nantes, Loire-Atlantique, France, 44093
        • Not yet recruiting
        • Laboratoire d'Explorations Fonctionnelles - Centre de Référence Maladies Neuromusculaires Rares, CHU Nantes
        • Contact:
        • Contact:
    • Normandy
      • Rouen, Normandy, France, 76031
        • Recruiting
        • Service de cardiologie & Service de Neurophysiologie - CHU de Rouen
        • Contact:
        • Contact:
    • Paris
      • Paris, Paris, France, 75013
        • Recruiting
        • Centre de référence pour les maladies cardiaques héréditaires
        • Contact:
    • Île-de-France Region
      • Garches, Île-de-France Region, France, 92380
        • Not yet recruiting
        • Service de Neurologie, Réanimation Pédiatriques, Hôpital Raymond Poincaré, Hôpitaux Universitaires, Paris-Ile-de-France-Ouest
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

2 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patient with an LMNA mutation that has led to the diagnosis of laminopathy affecting striated muscle
  • Presenting the symptoms of the disease, whether they are index cases or related to this index case (muscle weakness, tendon retractions with or without respiratory or cardiac involvement)
  • Have no contraindication to muscle or skin biopsy, i.e., 1) presence of a history of allergy to latex, antiseptics, local anesthetics and adhesive dressings, 2) Current oral or parenteral anticoagulant therapy (anti-vitamin K, heparins, anti-platelet agents, anti-factor X, anti-thrombin), 3) History of inherited (haemophilias, platelet diseases) or acquired (vitamin K deficiency, liver failure) coagulation disorders.
  • Patients (adult participant) or both holders of parental authority (minor participant) must sign a free and informed consent. If a minor has only 1 legal representative, the latter must attest to this on the consent form.
  • Patients affiliated to the general French social security system, to the French Universal Medical Coverage (CMU) or to any French equivalent scheme.

Exclusion Criteria:

  • Pregnant or breastfeeding women
  • Adult subject to legal protection measures (safeguard of justice, curatorship and guardianship).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Collection of biological material

Patients carrying LMNA mutation with no contrindication for skin and/or muscle biopsy:

  • from large families with striking intrafamilial phenotypic variability (3 families identified).
  • patients carrying p.Arg453Trp or p.Glu358Lys LMNA gene mutations
The skin biopsy is performed in the consultation outclinic room. A local anaesthetic (anaesthetic patch to be applied to the skin) is required for this procedure. The skin biopsy is usually performed on the front of the forearm (but can be performed on the arm, thigh or leg). After disinfection, a fragment of 3 to 4 mm in diameter is removed with a biopsy-punch (single-use device). If necessary, a suture can be placed. Otherwise, the wound is covered with Steristrip and a sterile dressing. The skin sample, intended for a fibroblast culture, will be placed in a flask to be kept at room temperature. It will be labelled with specific labels and sent to the local biological resource centre.
The muscle biopsy is performed in a sterile room. A local anaesthetic is required for this procedure. After selecting the muscle from which the sample will be taken (usually from the deltoid muscle at the shoulder stump), placing a sterile field and disinfecting, a small incision is made in the skin until the selected muscle is exposed. A bundle of muscle fibres of approximately 1 cm x 0.5 cm is removed. The skin is then sutured and covered with a sterile dressing. The procedure takes about 30 minutes (including patient set-up). The muscle sample will be divided into 2 fragments, one for myoblast culture, the other for frozen tissue. The 2 vials will be labelled with specific labels and then sent to the local biological resource centre

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Skeletal muscle severity outcome
Time Frame: 5 years

Will be a composite scale combining maximal motor acquisitions (sitting, walking, running) and what remains as motor skills with disease course (still running, only walking, only sitting, inability to sit)). In details:

  • The maximal motor acquisitions (M2A) : no motor acquisitions = 0, only rolling = 1, only sitting = 2, only walking = 3, running = 4.
  • The remaining motor skills (RMS) with disease course: still running = 3, only walking = 2, only sitting = 1, inability to sit = 0.

The composite scale for a given patient will be M2A + RMS.

5 years
Cardiac muscle severity outcome
Time Frame: 5 years
Will be a composite scale according to left ventricle ejection fraction (normal>55%, moderate <55% and >45%, severe<45%) and the presence or absence of conduction defects and arrhythmias.
5 years
Protective structural variant outcome
Time Frame: 5 years
Structural gene variants identified on patient biological materials by Whole Genome Sequencing (WGS), associated with the mild disease severity.
5 years
Protective differential gene expression outcome
Time Frame: 5 years
differential gene expression identified on patient biological materials by RNA sequencing (RNA-seq) associated with the mild disease severity.
5 years
Protective 3D chromatin conformation outcome
Time Frame: 5 years
3D conformation of chromatin identified on patient biological materials by Chromatin Immuno-Precipitaiton Sequencing (CHIP Seq) associated with the mild disease severity.
5 years
Aggravating structural variant outcome
Time Frame: 5 years
Structural gene variants identified on patient biological materials by Whole Genome Sequencing (WGS), associated with the worse disease severity.
5 years
Aggravating differential gene expression outcome
Time Frame: 5 years
Differential gene expression identified on patient biological materials by RNA sequencing (RNA-seq) associated with the worse disease severity.
5 years
Aggravating 3D chromatin conformation outcome outcome
Time Frame: 5 years
3D conformation of chromatin identified on patient biological materials by Chromatin Immuno-Precipitaiton Sequencing (CHIP Seq) associated with the worse disease severity.
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 8, 2022

Primary Completion (Estimated)

September 30, 2027

Study Completion (Estimated)

December 30, 2027

Study Registration Dates

First Submitted

March 30, 2022

First Submitted That Met QC Criteria

May 23, 2022

First Posted (Actual)

May 27, 2022

Study Record Updates

Last Update Posted (Actual)

March 4, 2026

Last Update Submitted That Met QC Criteria

March 3, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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