• Primary Ciliary Dyskinesia (PCD)
  • Primary Immunodeficiencies (PID)
  • Cystic Fibrosis (CF)
  • Bronchiectasis

Primary Ciliary Dyskinesia (PCD)

Primary ciliary dyskinesia (PCD), also known as "immotile cilia syndrome" or "Kartagener syndrome," is caused by genetic mutations that result in defects in the generation or correct function of motile cilia found in the airways and some other organs. PCD has been associated with mutations in 50 different genes (as of 2022). Children with PCD often have early, persistent wet cough and frequent ear infections. In addition to a chronic cough, this disease is also associated with recurrent or persistent infections of the lung, paranasal sinuses, and middle ears. Occurring in approximately 1 in 7,500 to 1 in 20,000 births, primary ciliary dyskinesia is an inherited disease that causes impaired clearance of bacteria from the upper and lower respiratory tracts. Half of the patients with primary ciliary dyskinesia have their internal organs reversed (known as situs inversus totalis), and affected individuals have reduced fertility.

Primary Immunodeficiencies (PID)

Primary immunodeficiencies are a heterogeneous collection of over 400 rare, inherited, chronic disorders in which the immune system functions improperly. Some of these conditions affect a single part of the immune system while others affect multiple components. Affected individual have an increased susceptibility to infection that can involve the skin, paranasal sinuses, middle ears, and the lungs. While many primary immunodeficiencies are diagnosed during infancy and early childhood, atypical forms can present later in life, often with clinical features that overlap with primary ciliary dyskinesia.

Cystic Fibrosis

Occurring in all races, cystic fibrosis is the most common, inherited disease of Caucasians, and affects many parts of the body, including the lungs, paranasal sinuses, skin, pancreas, intestines, liver, and male reproductive tract. Historically, the diagnosis of cystic fibrosis has been based on the presence of typical clinical features and positive laboratory studies, including abnormal sweat tests or two identified mutant cystic fibrosis transmembrane conductance regulator (CFTR) genes. However, it is clear that milder or variant forms of the disease exist, in which patients can have lung disease but normal or borderline elevated sweat tests or no identifiable CFTR mutations.


Bronchiectasis is an irreversible, pathological finding defined as enlargement (“ectasia”) of the airways (“bronchi’) of the lung, usually caused by chronic infection and permanent damage of the lower respiratory tract. Symptoms typically include a chronic, productive cough that yields purulent mucus, and other symptoms may include shortness of breath, chest pain, wheezing, and coughing up blood (“hemoptysis”). Affected individuals occasionally have increased respiratory symptoms caused by lung infections, requiring antibiotic therapy, and referred to as exacerbations.

RDCRN Contact Registry
Learn about all the benefits of joining the RDCRN Contact Registry.

Join Now