A genetic disorder of the lungs, sinuses, ears and motile cilia
Introduction to Primary Ciliary Dyskinesia (PCD)
Primary ciliary dyskinesia is a rare inherited condition in which motile cilia do not form or move normally. Impaired mucus clearance can cause a wet cough from early life, chronic sinus and ear disease, recurrent chest infections and bronchiectasis. PCD may also affect organ positioning and fertility.
- Motile cilia
- Chronic wet cough
- Bronchiectasis
- Nasal nitric oxide
- Ciliary microscopy
- Genetic testing
- Kartagener syndrome
- Fertility
Symptoms usually begin early
Many affected people have unexplained breathing difficulty after birth, a daily wet cough, persistent nasal congestion or recurrent ear disease from infancy or childhood.
No single test detects every case
Diagnosis should be made through a specialist PCD service using the clinical history and a combination of complementary investigations.
What is primary ciliary dyskinesia?
Primary ciliary dyskinesia is an inherited disorder affecting motile cilia: microscopic structures that beat in a coordinated way to move mucus, bacteria and inhaled particles out of the respiratory tract.
Motile cilia line the nose, sinuses, middle ear, trachea and bronchial tree. They also have important roles in reproduction and in determining left–right organ arrangement during early embryonic development.
In PCD, cilia may be absent, immotile or capable of movement that is ineffective or poorly coordinated. Mucus therefore remains in the airways for longer, creating an environment in which infection and inflammation can recur.
Over time, repeated infection and inflammation can damage the bronchial walls and cause bronchiectasis .
Healthy cilia act like a microscopic conveyor belt. In PCD, that conveyor belt is inefficient, so mucus and inhaled material are not transported out of the airways normally.
Where are motile cilia found?
Lower airways
Cilia move respiratory mucus towards the throat, helping remove bacteria, dust and other inhaled particles.
Nose and sinuses
Ciliary movement supports sinus drainage and clearance of nasal secretions.
Middle ear
Dysfunction can contribute to persistent middle-ear fluid, repeated infections and conductive hearing loss.
Embryonic node
Specialised cilia help establish normal left–right organ positioning during early development.
Sperm flagella
Sperm tails share structural components with motile cilia, so sperm movement may be reduced or absent.
Fallopian tubes
Ciliary activity helps transport the egg and early embryo towards the uterus.
Symptoms and clinical clues
PCD may resemble common childhood respiratory disease, asthma, recurrent viral infection or other causes of bronchiectasis. Suspicion increases when characteristic symptoms begin very early and remain persistent rather than episodic.
Neonatal respiratory distress
A full-term baby may develop unexplained rapid breathing, oxygen requirement or chest X-ray abnormalities shortly after birth.
Daily wet cough
A persistent mucus-producing or wet-sounding cough from early infancy is one of the most important clues.
Persistent rhinitis
Nasal congestion and discharge may be present throughout the year from early life.
Chronic sinusitis
Poor sinus drainage can cause facial pressure, congestion, reduced smell and recurrent infection.
Recurrent ear disease
Glue ear and otitis media may cause fluctuating hearing, speech-development or educational difficulties.
Recurrent chest infections
Exacerbations may cause increased cough, sputum, breathlessness, fatigue or fever and require repeated antibiotics.
Bronchiectasis
CT imaging may show widened airways, mucus plugging and airway wall thickening, sometimes from childhood.
Organ laterality differences
The heart and abdominal organs may be arranged as a mirror image or in a more complex pattern.
Reduced fertility
Some men have reduced sperm motility, while some women have impaired tubal transport.
Breathlessness
Breathlessness may develop from mucus obstruction, bronchiectasis, infection, airflow limitation or reduced fitness.
A persistent cough may warrant specialist chronic-cough investigation , particularly when it has been present since childhood.
Consider PCD in adults as well as children
Some people reach adulthood with a diagnosis of idiopathic bronchiectasis, chronic sinusitis or recurrent infection before the possibility of PCD is reconsidered.
How is PCD diagnosed?
PCD is diagnostically complex. No individual investigation is sufficiently sensitive and specific to identify every affected person, so testing should be coordinated through a specialist PCD diagnostic service.
- Clinical history The team reviews neonatal respiratory distress, lifelong wet cough, rhinitis, ear disease, bronchiectasis, organ laterality, fertility and family history.
- Exclude alternative explanations Cystic fibrosis, immune deficiency, aspiration and other causes of bronchiectasis may need investigation.
- Measure nasal nitric oxide Nasal nitric oxide is often markedly reduced in PCD and can support referral for further diagnostic testing.
- Obtain a nasal brushing Ciliated respiratory cells are collected gently from the nose for functional and structural analysis.
- Analyse ciliary movement High-speed video microscopy assesses beat frequency and, more importantly, the pattern and effectiveness of movement.
- Assess ciliary ultrastructure Transmission electron microscopy may identify characteristic defects in dynein arms, microtubules or other components.
- Assess ciliary proteins Immunofluorescence can show whether selected structural proteins are absent or located abnormally.
- Consider genetic testing A specialist panel may identify disease-causing variants and can clarify inheritance and family counselling.
| Test | What it assesses | Important limitation |
|---|---|---|
| Nasal nitric oxide | Measures nitric oxide produced within the nose and sinuses | Low levels support suspicion but do not confirm PCD alone |
| High-speed video microscopy | Assesses ciliary beat frequency and movement pattern | Infection and sample quality can cause secondary abnormalities |
| Transmission electron microscopy | Examines the microscopic internal structure of cilia | Some genetically confirmed forms have normal or non-diagnostic ultrastructure |
| Immunofluorescence | Evaluates the presence and location of selected ciliary proteins | Current antibody panels do not detect every molecular defect |
| Genetic testing | Searches for pathogenic variants in recognised PCD genes | A negative panel does not currently exclude all PCD |
| Air–liquid interface culture | Allows cilia to regrow away from acute infection and mucus | Cell culture may fail or require repeat sampling |
Normal electron microscopy does not exclude PCD
Some PCD-causing genetic variants disrupt ciliary function without producing a classic ultrastructural abnormality. A convincing clinical phenotype may therefore require further specialist testing even after non-diagnostic microscopy.
Nasal nitric oxide testing
Nasal nitric oxide, or nNO, is a rapid and non-invasive measurement. Many people with PCD produce very low amounts of nitric oxide within the nose and paranasal sinuses.
How the test is performed
Sampling
A small nasal probe samples gas from one nostril while the other remains open.
Breathing technique
Older children and adults usually perform a manoeuvre that closes the soft palate and separates nasal from lower-airway gas.
Interpretation
Results are assessed against the measurement technique, age and laboratory standards.
nNO is a screening test, not a stand-alone diagnosis
Acute viral infection, severe nasal obstruction, cystic fibrosis and technical factors may reduce nasal nitric oxide. Conversely, a minority of PCD genotypes can have results above commonly used screening thresholds.
Genetics and inheritance
PCD is genetically heterogeneous. Disease-causing variants have been identified in many genes required for the formation, organisation, transport and movement of motile cilia.
DNAH5 and DNAI1
Variants may disrupt components of the outer dynein arms, which generate force for ciliary movement.
CCDC39 and CCDC40
Variants can cause microtubular disorganisation and abnormal inner dynein-arm assembly.
RSPH1, RSPH4A and RSPH9
These genes are associated with radial-spoke or central-apparatus abnormalities and may not cause situs inversus.
CCNO and MCIDAS
Variants can result in too few motile cilia rather than a defect visible in each individual cilium.
Autosomal-recessive inheritance
Most PCD is inherited in an autosomal-recessive pattern. An affected person usually inherits one disease-causing variant in the same gene from each parent.
| Possible outcome for each pregnancy | Approximate probability | Meaning |
|---|---|---|
| Child inherits both altered copies | 25% | The child is expected to have PCD |
| Child inherits one altered copy | 50% | The child is usually an unaffected carrier |
| Child inherits neither altered copy | 25% | The child is neither affected nor a carrier of those family variants |
Not every form of PCD is autosomal recessive
Rare X-linked and autosomal-dominant forms have been described. Genetic counselling should therefore use the confirmed gene and family variants rather than assuming one inheritance pattern.
Kartagener syndrome and organ laterality
Kartagener syndrome is the historical term for the combination of PCD, chronic sinus disease, bronchiectasis and situs inversus. It is a subgroup of PCD rather than a separate ciliary disorder.
Situs inversus totalis
The thoracic and abdominal organs are arranged as a mirror image of their usual positions.
Dextrocardia
The heart is positioned mainly on the right side of the chest.
Situs ambiguus
Organ arrangement is neither conventionally normal nor a complete mirror image and may be associated with congenital heart disease.
Normal organ arrangement
Many people with PCD have situs solitus, meaning their organs are arranged conventionally.
Situs inversus does not usually cause symptoms by itself
It is nevertheless important for clinicians and surgeons to know the organ arrangement before interpreting symptoms, ECGs, imaging or planning procedures.
PCD, fertility and pregnancy
Fertility effects vary substantially by genotype and individual. PCD does not mean that biological parenthood is impossible, but specialist reproductive advice may be helpful.
Male fertility
Mechanism
Sperm flagella share structural proteins with motile respiratory cilia.
Possible effect
Sperm may be immotile or move inefficiently, reducing the likelihood of natural conception.
Options
Semen analysis and assisted reproduction, including IVF or intracytoplasmic sperm injection, may be considered.
Female fertility
Mechanism
Motile cilia within the fallopian tubes contribute to egg and embryo transport.
Possible effect
Natural conception may take longer, although many women with PCD become pregnant.
Ectopic pregnancy
Impaired tubal transport may increase ectopic-pregnancy risk, making early pregnancy assessment important.
Seek urgent help for possible ectopic pregnancy
Pregnancy accompanied by one-sided abdominal pain, shoulder-tip pain, vaginal bleeding, dizziness or collapse requires urgent medical assessment.
Management of primary ciliary dyskinesia
There is currently no routine treatment that corrects the underlying genetic defect. Management aims to improve mucus clearance, treat infection promptly, preserve lung function and address ear, sinus, hearing and fertility complications.
Daily airway clearance
A respiratory physiotherapist teaches an individualised technique to mobilise and clear mucus from the lungs.
Regular exercise
Physical activity supports mucus clearance, cardiovascular fitness, muscle strength and general wellbeing.
Sputum surveillance
Regular cultures help identify organisms and guide antibiotic treatment, including when symptoms change.
Prompt antibiotics
Respiratory exacerbations are treated according to symptoms, previous microbiology, severity and drug susceptibility.
Long-term antibiotics
Selected people with frequent exacerbations may be considered for preventative oral or inhaled antibiotic treatment.
Sinus care
Saline irrigation, treatment of infection and ENT assessment may reduce chronic nasal and sinus symptoms.
Hearing care
Audiology monitoring, educational support and hearing devices may be appropriate when middle-ear disease affects hearing.
Vaccination
Routine and risk-based vaccinations should be reviewed, including influenza, COVID-19 and pneumococcal vaccination.
Nutrition
Dietetic support may be useful when chronic infection, poor appetite or increased respiratory effort affects weight.
Psychological support
Treatment burden, repeated infection and fertility concerns can affect emotional wellbeing and family life.
People with established bronchiectasis can read more about airway clearance, sputum monitoring and bronchiectasis treatment .
Medicines used in PCD
| Treatment | Possible role | Important qualification |
|---|---|---|
| Antibiotics | Treat acute chest, sinus or ear infections | Choice should reflect microbiology, severity, allergy and previous response |
| Long-term macrolides | May reduce exacerbations in selected patients | Requires review of ECG risk, hearing, liver function and non-tuberculous mycobacterial cultures |
| Nebulised antibiotics | May be considered for selected chronic airway infection | Device, organism, tolerance and specialist monitoring are important |
| Hypertonic saline | May help hydrate secretions and support airway clearance | Benefit varies and a supervised tolerance assessment may be needed |
| Bronchodilators | May help when asthma, reversible obstruction or treatment- related bronchospasm is present | Not required routinely for every person with PCD |
| Inhaled corticosteroids | Used for coexisting asthma or another steroid-responsive airway disorder | They are not routine anti-inflammatory treatment for PCD alone |
| Intranasal corticosteroids | May help coexisting allergic rhinitis or nasal polyps | They do not correct the underlying ciliary defect |
Do not copy cystic-fibrosis treatment automatically
PCD and cystic fibrosis both impair mucus clearance, but their biology and evidence base differ. Medicines should be selected for the individual indication rather than transferred routinely from another disease pathway.
Further information is available in the guide to recurrent and complex chest-infection treatment .
Regular monitoring
Follow-up is usually multidisciplinary and may include respiratory medicine, physiotherapy, specialist nursing, ENT, audiology, microbiology, genetics and fertility services.
Symptom review
Cough, sputum, breathlessness, sinus disease, hearing and treatment burden are reviewed regularly.
Lung-function tests
Spirometry and other physiological tests help track airflow, lung volumes and functional change.
Sputum cultures
Samples may identify organisms such as Haemophilus influenzae, Staphylococcus aureus or Pseudomonas aeruginosa.
Chest imaging
CT imaging is used selectively to assess bronchiectasis, mucus plugging and structural progression.
ENT and hearing review
Persistent rhinosinusitis, glue ear and hearing impairment may require specialist assessment.
Treatment adherence
Airway-clearance technique, equipment hygiene, medicine burden and practical barriers are addressed.
Read about spirometry, gas-transfer testing and exercise assessment .
Living well with PCD
- Make airway clearance part of the routine A realistic daily plan is more sustainable than an overly complex technique that cannot be maintained.
- Increase clearance during infection Follow the physiotherapy plan for periods of increased sputum or worsening symptoms.
- Submit sputum early A sample obtained before antibiotics can improve microbiological guidance.
- Exercise regularly Choose enjoyable activity appropriate to lung health, fitness and other medical conditions.
- Avoid tobacco smoke Smoking and second-hand smoke add further injury to airways with already impaired clearance.
- Clean respiratory equipment properly Follow manufacturer and clinical-team instructions to reduce contamination.
- Keep an exacerbation plan Know which symptom changes should trigger sputum testing, increased airway clearance and medical contact.
- Seek support Specialist nurses, physiotherapists, patient organisations and counselling services can help with practical and emotional needs.
When should medical help be sought?
Contact the clinical team promptly for:
- a sustained increase in cough or sputum;
- a change in sputum colour, volume or smell;
- new fever, fatigue or loss of appetite;
- increasing breathlessness or wheeze;
- new chest pain;
- coughing up blood;
- falling lung-function or oxygen readings;
- recurrent ear pain or noticeable hearing deterioration.
Seek urgent or emergency help for:
- severe or rapidly worsening breathing difficulty;
- blue or grey lips or skin;
- collapse, fainting or new confusion;
- significant fresh haemoptysis;
- severe chest pain;
- very low or rapidly falling oxygen saturation;
- inability to speak because of breathlessness;
- possible ectopic pregnancy symptoms.
Call 999 for immediately life-threatening symptoms.
Conclusion
Primary ciliary dyskinesia is a rare inherited disorder in which motile cilia are absent, structurally abnormal or unable to move mucus effectively.
Important clues include neonatal respiratory distress, a daily wet cough from early childhood, chronic rhinitis, recurrent ear disease, bronchiectasis, laterality differences and reduced fertility.
Diagnosis requires specialist assessment because no single test detects every case. Nasal nitric oxide, high-speed video microscopy, transmission electron microscopy, immunofluorescence and genetic testing provide complementary information.
Kartagener syndrome describes PCD accompanied by situs inversus, bronchiectasis and chronic sinus disease. Many people with PCD have conventional organ positioning.
Treatment centres on individualised airway clearance, exercise, sputum surveillance, prompt antibiotics, sinus and ear care, vaccination and regular multidisciplinary monitoring.
Adults with lifelong wet cough, chronic sinus disease, recurrent infection or unexplained bronchiectasis can arrange a specialist bronchiectasis and respiratory infection assessment .
Frequently asked questions
What are the earliest signs of PCD?
Early clues include unexplained respiratory distress in a full-term newborn, persistent nasal congestion and a daily wet cough beginning in infancy.
Is PCD the same as cystic fibrosis?
No. Both can cause bronchiectasis and recurrent infection, but they have different genetic causes and biological mechanisms.
Is PCD the same as Kartagener syndrome?
Kartagener syndrome is a subgroup of PCD characterised by bronchiectasis, chronic sinus disease and situs inversus.
Can PCD be diagnosed from nasal nitric oxide alone?
No. A low result strongly supports suspicion in the correct clinical setting, but diagnosis requires additional specialist testing.
Can PCD be present with normal electron microscopy?
Yes. Some forms alter ciliary function without producing a classic ultrastructural defect visible on electron microscopy.
Does a negative genetic panel exclude PCD?
No. Genetic testing does not yet identify the cause in every clinically affected person.
Is PCD always inherited in an autosomal-recessive pattern?
Most PCD is autosomal recessive, but rare X-linked and autosomal-dominant forms exist.
Can someone with PCD have children?
Yes. Fertility varies. Some people conceive naturally, while others benefit from fertility assessment or assisted reproductive treatment.
Does PCD increase ectopic-pregnancy risk?
Tubal ciliary dysfunction may increase the risk. Early pregnancy assessment is advisable when pregnancy occurs.
Does every person with PCD develop bronchiectasis?
Bronchiectasis is common and becomes more likely with age, but its extent and severity vary considerably.
Are inhaled steroids routinely used in PCD?
No. They are normally reserved for coexisting asthma or another steroid-responsive airway condition.
Are antibiotics used for every cough?
Not necessarily. Antibiotics are used for suspected bacterial exacerbations and should be guided by symptoms, sputum microbiology and the agreed treatment plan.
Can adults be diagnosed with PCD?
Yes. Adults with lifelong wet cough, chronic sinusitis, hearing problems, infertility or unexplained bronchiectasis may receive a late diagnosis.
What is the outlook for someone with PCD?
Outcomes vary by genotype, infection history, severity of bronchiectasis, treatment adherence and access to specialist care. Many people lead active lives, but ongoing monitoring is important because lung disease can progress.
References and further information
- European Respiratory Society. ERS Task Force guideline for the diagnosis of primary ciliary dyskinesia. View the ERS diagnostic guideline
- American Thoracic Society. Diagnosis of Primary Ciliary Dyskinesia: an official clinical practice guideline. View the ATS diagnostic guideline
- Cambridge University Hospitals NHS Foundation Trust. Primary ciliary dyskinesia. View NHS patient information
- University Hospitals of Leicester NHS Trust. Primary Ciliary Dyskinesia service. View the specialist PCD service
- PCD Support UK. Diagnosis of primary ciliary dyskinesia. View PCD Support UK diagnostic information
- London Chest Specialist. Bronchiectasis diagnosis and treatment. Read about specialist bronchiectasis care
- London Chest Specialist. Chronic-cough specialist assessment. Read about persistent-cough investigation
- London Chest Specialist. Chest-infection diagnosis and treatment. Read about recurrent chest infections
- London Chest Specialist. Lung-function tests. Read about respiratory physiological testing
