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Characterization of the Interruptions of the GAA Expansion and Study of Their Influence on the Severity of Friedreich's Ataxia

NCT04346238 · Status: UNKNOWN · Type: OBSERVATIONAL · Enrollment: 120

Last updated 2020-04-16

No results posted yet for this study

Summary

Friedreich's ataxia (FA) is the most frequent recessive genetic ataxia with an estimated prevalence of 1/50 000. The first symptoms appear around the age of 10 years with a progressive course and the need for an armchair 10- 15 years after the first symptoms. More rarely the disease can present with a late onset (after the age of 25) with a picture characterized by spastic paraparesis and slower progression ("LOFA" for "Late Onset Friedreich Ataxia" or VLOFA for "Very Late Appearance of Friedreich's ataxia ").

AF is caused in 96% of cases by an expansion of GAAN triplets (N\> 100 repeats) located in intron 1 of the FXN gene, present on the two alleles, and, in the rest of the cases, by an associated expansion a point mutation or a deletion in trans. During molecular diagnostics, it is not uncommon to find the presence of interruptions within the GAA expansion. This results in the absence and / or the shift of peak (s) within the chromatogram.

To date, only the partial correlation between the size of the expansion and the age of onset of Friedreich's ataxia has been established. In particular, very atypical forms of AF with a late onset (after the age of 25) are in particular explained by the low number of repetitions in the expansion, typically between 100 and 500 repetitions. However, the presence of an interruption could stabilize the size of the expansion and, therefore, be mainly associated with expansions of small sizes and therefore with a late onset of the disease.

The objective of this study is therefore to analyse and caracterize the presence and the type of interruptions of the GAA expansions in a group of patients with FA ; this data will be correlated with the age at onset of FA.

Conditions

  • Friedreich Ataxia

Interventions

OTHER

Reuse of existing data from patients' medical records

Reuse of existing data from patients' medical records

Sponsors & Collaborators

  • Neurogenetic department, CHU Bordeaux

    collaborator UNKNOWN

  • Genetic Department , CHU Montpellier-France

    collaborator UNKNOWN

  • Neurology department, CHU La réunion

    collaborator UNKNOWN

  • University Hospital, Montpellier

    lead OTHER

Principal Investigators

  • Cecilia Marelli, MD · University Hospitals of Montpellier

Eligibility

Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2020-03-01
Primary Completion
2021-03-30
Completion
2021-09-30

Countries

  • France

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04346238 on ClinicalTrials.gov