Rare Genetic Disorders of the Breathing Airways
Mucociliary clearance, in which mucus secretions are cleared from the breathing airways, is the primary defense mechanism for the lungs. Inhaled particles, including microbes that can cause infections, are normally entrapped in mucus on the airway surfaces and then cleared out by the coordinated action of tiny hair-like structures called cilia. Individuals with primary ciliary dyskinesia, variant cystic fibrosis, and pseudohypoaldosteronism have defective mucociliary clearance. The purpose of this study is to collect clinical and genetic information about these three airway diseases to improve current diagnostic procedures.
Primary Ciliary Dyskinesia
|Study Design:||Observational Model: Cohort|
|Official Title:||Rare Genetic Disorders of the Airways: Cross-sectional Comparison of Clinical Features, and Development of Novel Screening and Genetic Tests|
- This is not an interventional study [ Time Frame: This is not an interventional study ] [ Designated as safety issue: No ]Not applicable. This is not an interventional study.
Biospecimen Retention: Samples With DNA
Respiratory cultures, nasal samples, and blood samples
|Study Start Date:||May 2006|
|Estimated Study Completion Date:||January 2016|
|Primary Completion Date:||October 2012 (Final data collection date for primary outcome measure)|
Two types of genetic diseases are associated with abnormal mucociliary clearance. The first type results in defective ciliary function and includes primary ciliary dyskinesia (PCD), also known as Kartagener Syndrome. The second type results in defective ion transportation and includes variant cystic fibrosis (CF) and pseudohypoaldosteronism (PHA). The clinical manifestations of these three diseases overlap, and current evaluation procedures are inadequate for an accurate and timely diagnosis. A delayed diagnosis, coupled with poorly defined disease categories, results in sub-optimal treatment regimens. The purpose of this study is to better define the clinical and genetic features of PCD, variant CF, and PHA to develop improved diagnostic procedures. The study will also compare prevalence and age-related information among the three diseases and classic CF. Outcomes of this study may lead to improved clinical care and novel therapeutic approaches for rare genetic disorders of the airways.
Prior to study entry, previous clinical data on all participants will be reviewed to ensure that individuals do not have common variants of asthma. In some cases, further clinical evaluation (sweat chloride testing, immunodeficiency testing, and a high-resolution computed tomography scan) may be recommended. Eligible participants will attend an initial six-hour study visit similar to a standard diagnostic evaluation. The participant's medical history will be reviewed and a physical examination will include height, weight, and vital sign measurements. Respiratory cultures, nasal samples, and blood will be collected. Non-invasive techniques will be used to measure oxyhemoglobin saturation levels and airflow; a chest x-ray will be required if none has been done in the last six months.
If a firm diagnosis of PCD or variant CF has not been established after completion of the first study visit, the participant may return for additional visits. Salivary and semen samples may be collected from some individuals. A sweat chloride test and nasal potential difference test may also be performed.
|United States, California|
|Palo Alto, California, United States, 94304|
|United States, Colorado|
|The Children's Hospital|
|Denver, Colorado, United States, 80218|
|National Jewish Health|
|Denver, Colorado, United States, 80206|
|United States, Maryland|
|Laboratory of Clinical Infectious Diseases, NIAID|
|Bethesda, Maryland, United States, 20892|
|United States, Missouri|
|St. Louis, Missouri, United States, 63130|
|United States, North Carolina|
|University of North Carolina at Chapel Hill|
|Chapel Hill, North Carolina, United States, 27599|
|United States, Washington|
|Children's Hospital and Regional Medical Center|
|Seattle, Washington, United States, 98105|
|The Hospital for Sick Children|
|Toronto, Ontario, Canada, M5G 1X8|
|St. Michael's Hospital|
|Toronto, Ontario, Canada, M5B IW8|
|Principal Investigator:||Michael R Knowles, MD||University of North Carolina, Chapel Hill|