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Clinical Variability in Marfan Syndrome

Not Applicable
Completed
Conditions
Marfan Syndrome
Interventions
Procedure: skin punch biopsy and molecular biology
Other: fibroblast culture and molecular biology
Registration Number
NCT01707563
Lead Sponsor
Assistance Publique - Hôpitaux de Paris
Brief Summary

Marfan syndrome is an autosomal dominant connective tissue disorder caused by mutations in the fibrillin-1 gene (FBN1). Penetrance of FBN1 mutations is complete but intra and inter familial clinical expressivity is extremely variable. The underlying mechanisms for variability are not understood. An interesting mechanism is that the expression level of the wild type and/or mutated allele may play a role in the determination of variability.

Principal objective: To evaluate in Marfan patients, if FBN1 expression level (non-mutated or mutated allele) modulates the clinical expression of the disease.

Judgment criteria : Correlation allelic expression level-phenotype Perspectives : To search the predictive factors of severity in order to ameliorate precocity of taking care.

Detailed Description

Marfan syndrome is an autosomal dominant connective tissue disorder caused by mutations in the fibrillin-1 gene (FBN1). Penetrance of FBN1 mutations is complete but intra and inter familial clinical expressivity is extremely variable. The underlying mechanisms for variability are not understood. An interesting mechanism is that the expression level of the wild type and/or mutated allele may play a role in the determination of variability.

Principal objective : To evaluate in Marfan patients, if FBN1 expression level (non-mutated or mutated allele) modulates the clinical expression of the disease in individuals from families with clinical variability (intrafamilial) and in independant probands (interfamilial).

Judgment criteria : Correlation allelic expression level-phenotype Method : In Marfan patients with a FBN1 nul allele, FBN1 RNA will be extracted from a fibroblast culture. Allelic FBN1 expression level will be performed by quantitative RT-PCR and then compared with clinical evaluation.

Number of subjects : 160 subjects, 45 Marfan patients in 15 independent families, 5 patients with the same mutation, 30 with a private mutation leading to a nul allele and 80 non Marfan subjects.

Perspectives : To search the predictive factors of severity in order to ameliorate precocity of taking care.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
160
Inclusion Criteria
  • Man or woman > 18 years old
  • With a mutation in FBN1 gene
  • Has signed an informed consent form
Exclusion Criteria

-No affiliated to a Healthcare System.

Study & Design

Study Type
INTERVENTIONAL
Study Design
FACTORIAL
Arm && Interventions
GroupInterventionDescription
Marfan patientsskin punch biopsy and molecular biologyStudy participants were recruited between 11/2009 and 10/2011, among adult patients consulting in the Multidisciplinary Marfan Clinic of our University Hospital, and having a known mutation in the FBN1 gene. There, patients are evaluated by geneticists, rheumatologists, cardiologists, and ophthalmologists. Systematic slit-lamp examination, cardiac ultrasonography, and radiological investigations are also performed. A skin punch biopsy was used to establish a fibroblast cell culture. We determined mRNA levels for FBN1 and compared it to the clinical involvement.
control patientsfibroblast culture and molecular biologyFibroblasts were obtained from non Marfan patients (cell bank). We determineed mRNA level for FBN1 for each allele.
Primary Outcome Measures
NameTimeMethod
FBN1 expression level6 months

Evaluation in Marfan patients, of FBN1 expression level (non-mutated or mutated allele) compared to the clinical expression of the disease in idividuals

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Centre de Reference Maladie de Marfan Et Apparente

🇫🇷

Paris, Ile de France, France

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