Clinical trial NCT04417777: Genetic Study of the Dilatations of the Idiopathic Bronchi in French Polynesia
Official title: Etude génétique Des Dilatations Des Bronches Idiopathiques en Polynésie française
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Idiopathic Bronchiectasis
Keywords: Genetic Disease
Idiopathic Bronchiectasis Polynesia
polynesia
Lead sponsor: Centre Hospitalier Intercommunal Creteil
Sponsor class: OTHER
First posted: 2020-06-05
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Polynesian patient with dilatation of idiopathic bronchi

Brief summary: 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


Eligibility criteria: \*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

Primary outcomes:
measure: identification of genetic mutation
timeFrame: Anytime in the period of 10 years
Secondary outcomes:
measure: Clinical phenotype
timeFrame: Anytime in the period of 10 years
measure: scannographic description
timeFrame: Anytime in the period of 10 years
measure: Effect on the splicing of messenger RNA
timeFrame: Anytime in the period of 10 years
measure: transcriptome of patients
timeFrame: Anytime in the period of 10 years
Other outcomes:
Locations:
city: Papeete
country: French Polynesia
facility: CH Polynesie Française
Study officials:
References: