Whole genome sequencing of Korean patients with idiopathic bronchiectasis and their family will perform to identify disease-causing variants.

Idiopathic bronchiectasis may be a manifestation of genetic diseases such as cystic fibrosis, primary ciliary dyskinesia, etc. Diagnosis of these rare genetic diseases is crucial not only because some of the rare diseases developed already effective treatment options, but also the detection of syndrome enables us to detect other organ damages before the deterioration of them.

Several diagnostic tools have been developed; however, the genetic panel has limited screening efficacy due to the genetic heterogeneity of diseases. Even more, especially in Korea, the incidence of idiopathic bronchiectasis caused by the genetic disease is rare, most clinics have limited to assess specialized diagnostic tools such as the specialized genetic panels, sweat chloride test, and the electromagnetic detection tools for ciliary movement.

Whole genome sequencing may be an excellent solution to identify the neglected genetic diseases causing idiopathic bronchiectasis and explore the heterogeneity of disease-causing variants in Korean patients.

Inclusion Criteria:

• If the patient has bronchiectasis proved by computed tomography (CT).
• The clinical features of the patient are suitable for ciliary dysfunction disease (primary ciliary dyskinesia, cystic fibrosis), alpha1-antitrypsin deficiency, and primary immune deficiency (hyper-immunoglobulin E syndrome, hypogammaglobulinemia, activated phosphoinositide 3-kinase (PI3K) delta syndrome, bare lymphocyte syndrome)
• The patient has no apparent medical events causing bronchiectasis.

Exclusion Criteria:

• If the patient does not agree or withdraw
• If the patient has any clear etiology causing bronchiectasis including AIDS, malignancy, receiving immunosuppressant or chemotherapy.

Among the patients visiting Seoul National Univerisity Hospital outpatient clinic, bronchiectasis patients who have no clear etiology of bronchiectasis and their family will be enrolled.