Key Facts
- People with PCD have mutations in their genes that control the structure and function of cilia, the tiny hairlike structures that line the airways, and other organs.
- PCD is often initially misdiagnosed because symptoms can mimic many other lung diseases such as asthma, cystic fibrosis, chronic allergies, bronchitis or bronchiectasis of unknown cause.
- Infection and inflammation eventually lead to bronchiectasis in almost all adults with PCD.
- Approximately 1 of every 10,000 to 30,000 babies worldwide are born with PCD.
What is Primary Ciliary Dyskinesia?
Cilia are tiny hair-like structures on the surface of cells in many parts of your body, including your lungs. When they function correctly, cilia beat together in a wave-like motion to move mucus, germs and other foreign particles up toward your mouth where they can be coughed or sneezed out. People with PCD are born with genetic mutations that cause the cilia to be the wrong size, abnormally shaped, move incorrectly, not move at all or are missing entirely.
Because of these abnormalities, the cilia cannot work properly to clear mucus from your lungs, which can cause mucus buildup and lead to infections, such as bronchitis and pneumonia. Repeated infections can cause damage to your lungs and airways and leads to the development of bronchiectasis in almost all adults with PCD.
Cilia that do not work properly elsewhere in the body can cause chronic, recurring ear and sinus infections. Abnormal cilia in the reproductive tract also commonly cause infertility, particularly in males. About half of people who have PCD have a condition called situs inversus, meaning the position of internal organs in the body is reversed from normal. While not harmful by itself, situs inversus can be a clue in diagnosing PCD.
Who Is at Risk for PCD?
PCD is a disease that is genetic and recessive, meaning that the only way to get it is by inheriting it from both parents. Additionally, both parents must contribute a defective copy of the same gene to their child for the baby to be born with PCD. More than 50 different genetic mutations that affect cilia development have been identified in people with PCD, and the pattern of inheritance is complex and not well understood.
Men and women are equally likely to be born with PCD. It affects people from all racial and ethnic groups.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.
Page last updated: August 6, 2026
