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AtaxiaBASE-AARNCT04099914

Validation of a Clinical Algorithm for the Diagnosis of Recessive Ataxias

An observational study of Ataxia, run by University Hospital, Montpellier at 1 site in France.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The field of clinical diagnosis of recessive cerebellar ataxias (ARCA) is particularly complex and Next Generation Sequencing (NGS) techniques have revolutionized this neuro-genetic field. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Ataxia
How many people
150 participants
Where
1 siteFrance
Study dates
1 Nov 2019to 30 Mar 2022
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Adut Patients with suspicion of recessive cerebellar ataxia , with onset before the age of 50 and with negative molecular analisys for Friedreich ataxia and dominant spinocerebellar ataxias due to trinucleotide expansion. .

Who may be able to join

  • having a predominant phenotype of pure or complex cerebellar ataxia of probable genetic origin (after exclusion of acquired, inflammatory, tumoral, infectious or toxic forms) - having started before the age of 50; - evoking a modality of recessive transmission (sporadic cases, brothers or sister affected, consanguinity of the parents) - in which dominant genetic forms due to CAG expansion (SCA1, SCA2, SCA3, SCA6, SCA7) and pre-mutation of the FMR1 gene (if onset after age 45)

Who cannot join

  • objecting to the computer processing of the data contained in the medical file.

Trial locations and contacts

1 site in 1 country.

France1 site
  • Uh Montpellier

    Montpellier, 34295

Other trials in France

About this study

Official title: Exploitation of a BAse of Genetic Data (Obtained by Next Generation SEquencing) for the Validation of a Clinical Algorithm for the Diagnosis of Recessive Cerebellar Ataxias

The field of clinical diagnosis of recessive cerebellar ataxias (ARCA) is particularly complex and Next Generation Sequencing (NGS) techniques have revolutionized this neuro-genetic field. The current challenge is to optimize the analysis of genetic data generated by NGS because: the processing of data remains very laborious; diagnostic yeld less than 50%; the interpretation of the variants sometimes very difficult. For this purpose of optimization, the team of the University Hospital of Strasbourg has developed a computer algorithm based on 124 clinical and para-clinical parameters (derived from the data of the literature), useful to guide the genes to be targeted in priority by genetic analysis, in the context of a suspicion of ARCA (> 60 known genes); this algorithm was validated retrospectively in 834 patients with genetically confirmed ARCA (92% Sense, 95% Spec). However, these 834 patients are often the same as those described in the literature and used for the elaboration of the algorithm. This introduces a bias in the initial evaluation of the algorithm, which therefore requires validation in clinical practice, from a cohort of patients referred for suspected ARCA (with or without a found genetic mutation). At the same time, Montpellier's genetics laboratory has developed a bioinformatic method for the search for copy number variations (CNV) that can be applied in a targeted manner to the genes predicted by the algorithm.

The principal aim of this study is the validation of a semi-automated clinical algorithm for NGS molecular diagnosis of ARCA; the secondary objective is to evaluate if the application of this algorithm coupled with a targeted bioinformatic analysis can increase the diagnostic yield of the NGS analysis.

Read the detailed description

Design: Retrospective study based on clinico-genetic data. Total research duration: 22 months Plan of the study : More than 150 patients referred for ARCA suspicion have been analyzed by NGS (Montpellier platform) since September 2013. The clinical data of these patients will be entered at the computer level into the algorithm to obtain the prediction of the gene involved (under the form of a probability for each of the genes known to ARCA). The investigators will compare this result with that obtained by standard NGS analysis. For patients without molecular diagnosis defined after standard NGS analysis, the investigators will take the 5 most probable genes selected on the basis of the algorithm in order to carry out an in-depth analysis of the variants found and a bioinformatic analysis by semi-automatic detection of CNVs. Main Evaluation Criterion: Concordance of the algorithm with standard NGS analysis for the genetic diagnosis of ARCA. Secondary evaluation criterion:% of patients for whom the prediction based on the algorithm suggested the correct diagnosis (subsequently confirmed after revision in the detail of the genetic data) while the standard genetic analysis was not not informative. Statistical Analysis: The investigators will perform a concordance analysis (Cohen's k) to validate the algorithm in clinical practice. For a given patient, there will be concordance if: i) one of the first 5 genes predicted with the highest probability by the algorithm is compatible with the mutation found after standard NGS or ii) if no gene is predicted by the algorithm (score <20) and no mutation found by NGS analysis.

Conditions
Ataxia
Keywords
Cerebellar ataxia, Neurogenetics, Next generation sequence, Clinical algorithm
Medical subject headings
Ataxia, Cerebellar Ataxia

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Agreement between the prediction of the algorithm and the result of the standard NGS analysis

    In order to validate in clinical practice a semi-automated clinical algorithm designed to guide the molecular diagnosis obtained by Next Generation Sequencing (NGS) in patients with suspected Autosomal Recessive Cerebellar Ataxia (ARCA), we will measure the agreement between the prediction of the algorithm and the result of the standard NGS analysis. For each patient the agreement is defined as: 1) one of the first 5 gene predicted with the highest probability by the algorithm is also the mutated gene found after the NGS analysis; 2) if no gene is predicted by the algorithm (= none of the gene has a prediction score > 20) and no mutation is found after NGS analyses.

    Measured: 1 day

Secondary outcomes (1)
  1. Percentage of patients for whom the prediction based on the algorithm suggested the right diagnosis, while the standard NGS analysis was not informative

    The secondary objective is to evaluate whether the application of this algorithm, coupled with a targeted bioinformatic analysis, changes the diagnostic yield compared to a NGS analysis performed in a conventional manner. Therefore, the secondary outcome will be the percentage of patients for whom the prediction based on the algorithm suggested the corrected diagnosis (confirmed in a second time after the review of the genetic data derived from NGS after the application of a targeted bioinformatic analysis), while the standard NGS analysis (blinded to algorithm prediction) was not informative

    Measured: 1 day

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Sep 2019
  2. Study start1 Nov 2019
  3. Primary completion30 Mar 2022
  4. Study completion30 Mar 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case only
Time perspective
Retrospective
Enrolment
150 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04099914
Sponsor's protocol ID
RECHMPL18_0431
Acronym
BASE-AAR
Status last verified
Apr 2022
First submitted
9 Sep 2019
Last updated
12 Apr 2022
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: NC

Questions about this trial

What is this clinical trial studying?

An observational study of Ataxia, run by University Hospital, Montpellier at 1 site in France.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Apr 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Agreement between the prediction of the algorithm and the result of the standard NGS analysis (time frame: 1 day). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Apr 2022.

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