Modifying Genes in Neurofibromatosis 1 (NFGENMODIF)

Study of the Neurofibromatosis 1 Expression: Identification of the Modifying Genes

Thanks to the investigators previous study the investigators demonstrated the influence of modifying genes in the phenotypic expression of neurofibromatosis 1 (Hum Mol Genet. 2009; 18 (15) :2768-78). Indeed, analysis of the intra-and inter-family variability performed using the investigators phenotype/genotype database demonstrated a strong genetic component for most clinical features. The investigators results suggest the involvement of genetic factors, not related to the NF1 gene, the modifiers. The objective of this project is to identify the modifiers involved in the variability of clinical expression of NF1. The investigators will focus in particular variants involved in the development and progression of neurofibromas.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Neurofibromatosis 1(NF1) is a rare autosomal dominant disorder with an incidence of one birth out of 3000. NF1 gene is located in 17q11.2. The penetrance is near 100% by the age of 8 and the de novo mutations represent half the cases. The product of NF1 gene is neurofibromin, a protein controlling cellular differentiation and proliferation. Phenotypic expression is variable even in the same family. Neurofibromatosis 1 is characterized by café au lait spots, freckling of the folds, Lisch'nodules (hamartomas of iris) and multiple neurofibromas. Manifestations of neurofibromatosis 1 are pleiotropic, potentially severe and unpredictable. Morbidity and mortality associated to neurofibromatosis 1 are linked with complications, optic pathway gliomas, neurofibromas of the spine or of peripheral nerves, learning disabilities, scoliosis and bone abnormalities and vasculopathy. The investigators already demonstrated the existence of modifiers, genes modifying the phenotypic expression of neurofibromatosis 1 (Hum Mol Genet. 2009;18(15):2768-78). Indeed, a quantitative analysis of inter and intrafamilial variability performed with the data of the investigators phenotype/genotype database showed a strong genetic component for most studied clinical traits with an estimated heritability from 44 and 45% for subcutaneous and plexiform neurofibromas, to 66% for small café au lait spots. The investigators also showed that the NF1 gene had minor effect in the phenotypic variability. The investigators results suggested the implication of genes non linked to NF1 gene. The identification of these variants called modifiers of the phenotype is possible thanks to the investigators vast collection of patients and its statistical power. The aim of the present study is to identify in the human genome genetic variants in the evolving pattern of the most frequent manifestation of neurofibromatosis 1, neurofibromas. The genetic association studies are the most adapted in that purpose. The investigators bank includes at the present time 1099 patients of 575 families with genotypes, phenotypes and DNA samples.

The investigators will include 450 index cases more to have around 1000 independent patients with neurofibromatosis 1 to get a 90% statistical power to detect variants of 30% frequency in the general population and having an effect of odds ratio of 2 for studied trait. The investigators will use Affymetrix® Genechips 6.0 covering well the whole genome.

Identification of the variants will provide new comprehension of pathophysiology and new targets for treatment.

Study Type

Observational

Enrollment (Anticipated)

450

Contacts and Locations

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

Study Locations

      • Creteil, France, 94010
        • Henri Mondor Hospital

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

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Adult patients with neurofibromatosis 1 according to the NIH criteria followed in NF France network, a national network devoted in to neurofibromatosis 1

Description

Inclusion Criteria:

  • Aged of 18 or more
  • Patient with neurofibromatosis 1 according the NIH criteria :
  • Six or more café au lait macules over 15 mm in greatest diameter in postpubertal individuals
  • Two or more neurofibromas of any type or one plexiform neurofibroma
  • Freckling in the axillary or inguinal regions (Crowe´s sign)
  • Optic glioma
  • Two or more Lisch nodules (iris hamartomas)
  • A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex with or without pseudoarthrosis
  • A first-degree relative (parent, sibling, or offspring) with NF1 by the above criteria
  • The criteria are met in an individual if two or more of the features listed are present.

Exclusion Criteria:

  • Children (< 18 year-old)
  • One member of the family already included in the study

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
NF1GeneModif Cohort
Adult patients with neurofibromatosis 1
No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Identification of the genetic variants involved in variability of clinical expression of neurofibromatosis 1.
Time Frame: 3 years
3 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

May 1, 2012

Primary Completion (ANTICIPATED)

September 1, 2015

Study Completion (ANTICIPATED)

September 1, 2015

Study Registration Dates

First Submitted

May 29, 2012

First Submitted That Met QC Criteria

July 25, 2012

First Posted (ESTIMATE)

July 26, 2012

Study Record Updates

Last Update Posted (ESTIMATE)

June 16, 2014

Last Update Submitted That Met QC Criteria

June 13, 2014

Last Verified

June 1, 2014

More Information

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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