Genetic Study of the Dilatations of the Idiopathic Bronchi in French Polynesia

Etude génétique Des Dilatations Des Bronches Idiopathiques en Polynésie française

Bronchiectasis, defined by an increase in bronchial caliber and thickening of the bronchial wall, is associated with recurrent respiratory infections, chronic cough and bronchorrhea, and a frequent progression to chronic respiratory failure. Investigator distinguish focal bronchiectasis usually resulting from a localized cause and diffuse bronchiectasis which the possible causes are multiple (immune deficiencies, genetic diseases, auto immune pathologies, aspergillosis broncho -allergic lung, sequelae of pulmonary infections).The etiological assessment is negative in 26 to 53% of cases, defining the idiopathic bronchiectasis. However, the discovery of an underlying cause can change the patient's management (up to 37% of cases).

Despite the lack of epidemiological data in French Polynesia, Australian and New Zealand studies found a high prevalence of bronchiectasis in Polynesians. Few clinical studies published in the early 1980s suggested a ciliary origin.

Due to its geographic characteristics, the Polynesian population constitutes an interesting ethnic group. Indeed, there is a low genetic mixing and the prevalence of certain genetic diseases like the syndrome of Alport or some hereditary retinal dystrophies are high. This type of population is very suitable for discovering new genes in human pathology.

Investigator decided to conduct an observational study to find an underlying genetic cause of bronchiectasis in Polynesians by performing a whole exome sequencing. Investigator chose to study index cases defined by an upset of symptoms during the childhood, a family history of idiopathic bronchiectasis, and/or a consanguinity. Investigator also want to study healthy first degree relatives, in order to be able to better identify the clinical significant of DNA variants and focus the analysis on those that may be pathogenic

Study Overview

• Status: Completed
• Conditions: Idiopathic Bronchiectasis
• Intervention / Treatment: Genetic: Blood Test

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• French Polynesia
  • Papeete, French Polynesia
    • CH Polynesie Française

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Polynesian patient with dilatation of idiopathic bronchi

Description

*Patients

Inclusion Criteria:

• Polynesian adult more than18 years
• dilatation of idiopathic bronchi confirmed to thoracic CTscan
• Negative etiological balance (including sweat test, research of Dyskinesia Ciliary Primitive and immunological check-up)
• Appearance of symptoms in childhood, or family history of chronic bronchial disease, or notion of inbreeding
• Signed consent
• Affiliated with a social security system

Exclusion Criteria:

• Refusal to participate in the study

  *Relatives

• First-degree healthy relatives
• Polynesian adult more than 18 years
• Signed consent
• Affiliated with a social security system

Exclusion Criteria:

• Refusal to participate in the study

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Polynesian patient; Patient with dilatation of idiopathic bronchi	Genetic: Blood Test; Blood analysis
Relatives of polynesian patient; Healthy	Genetic: Blood Test; Blood analysis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
identification of genetic mutation	New mutation in the coding region or mutation located outside the coding regions on the transcriptome	Anytime in the period of 10 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical phenotype	Extra-respiratory history Bronchial colonizations Scannographic aspect	Anytime in the period of 10 years
scannographic description	Extra-respiratory history Bronchial colonizations Scannographic aspect	Anytime in the period of 10 years
Effect on the splicing of messenger RNA	correlation genotype/phenotype	Anytime in the period of 10 years
transcriptome of patients	correlation genotype/phenotype	Anytime in the period of 10 years

Collaborators and Investigators

• Sponsor: Centre Hospitalier Intercommunal Creteil

Study record dates

Study Major Dates

• Study Start (Actual): February 10, 2022
• Primary Completion (Actual): March 8, 2022
• Study Completion (Actual): August 8, 2024

Study Registration Dates

• First Submitted: May 26, 2020
• First Submitted That Met QC Criteria: June 2, 2020
• First Posted (Actual): June 5, 2020

Study Record Updates

• Last Update Posted (Actual): August 14, 2024
• Last Update Submitted That Met QC Criteria: August 13, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: Genetic Disease; Idiopathic Bronchiectasis Polynesia; polynesia
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Bronchial Diseases; Bronchiectasis
• Other Study ID Numbers: POLYGENET

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No