Ciliary dyskinesia with transposition of ciliary microtubules is a rare genetic problem that affects tiny hair-like structures in the body called cilia. Cilia sit on the surface of cells in the nose, sinuses, lungs, ears, and some parts of the reproductive system. In healthy people, cilia beat in a smooth, regular way and move mucus, germs, and dust out of the airways. In this disease, the inner “skeleton” of the cilia (made from small tubes called microtubules) is in the wrong position, a change called microtubule transposition. Because of this wrong position, the cilia beat in a weak, uncoordinated, or abnormal way. This makes mucus clearance very poor and leads to repeated infections in the nose, sinuses, lungs, and middle ears.
This condition is part of a bigger group of disorders called primary ciliary dyskinesia (PCD). PCD is an inherited (passed down in families) disease where cilia structure or movement is abnormal from birth. In the special form with transposition of ciliary microtubules, the usual “9+2” pattern of microtubules inside the cilium is changed, for example to an “8+4” pattern, because one of the outer microtubule pairs moves into the center. This change makes the cilia less effective at moving mucus and can cause chronic cough, sinus problems, ear infections, and sometimes wrong position of internal organs (such as the heart on the right side).
Over time, the repeated infections and stuck mucus can damage the airways. This can lead to bronchiectasis, a condition where the breathing tubes become widened and scarred. Many people also have nasal congestion all year, chronic sinusitis, and fluid in the middle ear, which can cause hearing problems. Some males may have reduced sperm movement and infertility because the tail of the sperm has a structure similar to cilia.
Other names
Doctors may use different names or phrases for this condition. These names usually point to the same or very similar disease:
Primary ciliary dyskinesia with transposition defect – highlights that it is a form of PCD where the inner microtubule pattern is moved or “transposed.”
Microtubular transposition–type primary ciliary dyskinesia – stresses that the main structural defect is in the microtubules inside the cilium.
Ciliary dyskinesia due to microtubular defects – a broader term used in some studies that includes transposition and related microtubular problems.
Kartagener-like syndrome with microtubular transposition – used when the patient has chronic sinusitis, bronchiectasis, and organ reversal (situs inversus) plus this specific ciliary defect.
Types
There is no single worldwide standard list of “types” only for this exact defect. However, based on how the disease shows in real life, doctors often think in a few clinical patterns:
Type 1: Classic lung-dominant form
People have strong lung and airway symptoms, such as chronic cough and repeated chest infections, but no clear organ reversal or heart defects. The main problem is in the respiratory cilia with microtubular transposition.Type 2: Form with situs inversus or other organ position problems
Here, the internal organs, such as the heart, liver, or stomach, may be on the opposite side from normal (situs inversus) or in mixed positions. This happens because cilia also help guide organ position when the baby is developing in the womb.Type 3: Form with severe ear and sinus disease
In this pattern, chronic sinusitis, nasal polyps, and middle ear fluid or infections are very strong features. Lung disease may still be present but sometimes appears later or is milder at the start.Type 4: Form with marked fertility problems
Some patients, especially males, mainly seek help for infertility. Tests later show abnormal sperm tail movement and the same microtubular transposition defect in cilia of the airway or nose. Women may have trouble getting pregnant or higher risk of ectopic pregnancy.Type 5: Mixed ultrastructural defects
In some people, microtubular transposition appears together with other ciliary defects, such as missing dynein arms. These mixed patterns may cause an even more severe disease course.
Causes
Remember: this disease is mainly caused by genetic changes that affect how cilia are built and how they move. Most causes listed here are different ways genes and family history can contribute.
Autosomal recessive inheritance
Most people with this condition inherit one faulty gene from each parent. The parents are usually healthy carriers but each pregnancy has a 1 in 4 chance of having an affected child.Gene mutations affecting microtubule organization
Some gene changes alter proteins that keep the “9+2” microtubule pattern in the correct place. When these proteins do not work, one of the outer microtubules can shift into the center and cause transposition.Mutations in central pair complex genes
Certain genes control the central pair of microtubules and their support structures. When these genes are faulty, the central structure may be lost or replaced in the wrong way, which leads to abnormal beating.Mutations in radial spoke or linker proteins
Radial spokes connect the central pair to the outer doublets. Defects in these proteins can destabilize the whole inner structure and favor transposition changes seen on electron microscopy.Mutations in genes for cilia assembly (biogenesis)
Some genes guide how cilia are built during cell growth. If these “assembly” genes are damaged, the cell may still make cilia, but with incorrect inner patterns like microtubular transposition.Mutations in inner dynein arm–related genes
Even though the main defect here is microtubule position, some patients also have dynein arm changes. Dynein arms are motor proteins that make cilia move. When they are abnormal with transposition, movement becomes especially weak.Mutations in outer dynein arm–related genes
In a subset of cases, genes that produce outer dynein arms are also affected. This can combine with microtubular transposition and increase the severity of ciliary dysfunction.Family history of primary ciliary dyskinesia
Having brothers, sisters, or close relatives with PCD or related conditions raises the chance that a person has the same or a similar gene defect, including microtubular transposition.Consanguinity (parents related by blood)
When parents are cousins or otherwise related, they are more likely to carry the same rare gene change. This increases the chance of autosomal recessive diseases like this form of PCD.New (de novo) mutations
In some rare people, the harmful gene change may appear for the first time in that child and may not be present in the parents. This is less common but still possible.Mutations that affect ciliary length and stability
Genes that control how long cilia grow and how stable their structure is can, when damaged, lead to unstable microtubule patterns and transposition type defects.Mutations interfering with ciliary beat regulation
Some genes fine-tune the rhythm and pattern of ciliary beating. When they are abnormal, cilia may show disorganized movement linked with structural microtubule changes.Mutations in genes shared by sperm tail and airway cilia
The same structural proteins are used in both airway cilia and sperm tails. Damage to these genes can cause both respiratory disease and male infertility, often with microtubular defects.Compound heterozygous mutations (two different faulty copies)
Some patients have two different harmful mutations in the same gene (one from each parent). Together they disrupt the protein and cause this ciliary disorder.Mutations in less well-known PCD genes
New PCD genes continue to be discovered. Some of these are linked especially to microtubular and central complex defects seen under electron microscopy.Complex genetic background (multiple gene variants)
In some people, several mild variants in different cilia genes may act together and raise the risk of a microtubular transposition phenotype, even if each change alone is small.Genetic modifiers influencing severity
Other genes that are not directly ciliary may change how severe the disease becomes. They can modify infection risk, lung inflammation, and organ laterality outcomes.Population founder mutations
In some regions or ethnic groups, one old mutation may be common because of a “founder effect.” People in these groups can have higher rates of PCD, including transposition subtypes.Lack of protective genetic variation
Some people may lack certain protective variants that help cilia resist damage. Without these, the effect of a microtubular gene change can be stronger.Unknown or not yet discovered gene defects
Even after modern genetic testing, a part of patients with clear microtubular transposition on electron microscopy still have no identified mutation. This suggests there are more cilia genes that researchers have not yet fully mapped.
Symptoms
Chronic wet cough
The person often has a daily cough that brings up mucus, starting in childhood or even infancy. It does not fully clear with usual treatment and comes back again and again because mucus removal is poor.Repeated chest infections
People get frequent lung infections, such as bronchitis or pneumonia. Germs grow in the thick mucus that is not moved out by the weak cilia, so infections keep returning.Bronchiectasis
Over time, the breathing tubes become widened and scarred. This condition, called bronchiectasis, causes more cough, thick sputum, and sometimes blood-streaked mucus.Year-round blocked or runny nose
Many patients have a stuffy or runny nose most of the time, not just during “colds.” This is due to chronic rhinitis and poor clearance of mucus in the nasal passages.Chronic sinusitis
The sinuses become inflamed and filled with mucus. People may have facial pain, pressure, headaches, and post-nasal drip. Sinus infections may happen many times each year.Middle ear infections and fluid (otitis media)
Children often get repeated ear infections or fluid behind the eardrum. This happens because cilia in the Eustachian tube do not clear fluid well. It can cause ear pain and sometimes burst eardrums.Hearing problems
Long-term fluid and infections in the middle ear can lead to hearing loss. This can affect speech development and learning in children if not treated.Breathlessness and wheezing
Because the lungs are inflamed and airways may be narrowed, the person can feel short of breath, especially during exercise or infections, and may wheeze like asthma.Neonatal respiratory distress
Many babies with this condition have breathing trouble soon after birth, even though there is no clear infection. They may need oxygen or special care in a newborn unit.Persistent wet “rattly” breathing in infants
Babies and toddlers often have a noisy chest and wet-sounding breathing for many weeks or months. Parents may notice that symptoms never fully go away between “colds.”Situs inversus (organs reversed)
About half of patients with PCD have the heart and some organs on the opposite side from normal. This is called situs inversus and may be found on chest X-ray or ultrasound even if the person feels well.Chronic fatigue and poor exercise tolerance
Because their lungs do not work fully and infections are frequent, many people feel tired, get out of breath quickly, and cannot keep up with peers in sports or physical work.Male infertility
Men may have reduced sperm motility, meaning sperm do not swim well. This makes it harder to father a child naturally, even if sperm count is normal.Female subfertility or ectopic pregnancy
Women may have trouble getting pregnant or may be at higher risk of ectopic pregnancy because cilia in the fallopian tubes do not move the egg properly.Clubbing of fingers and signs of chronic lung disease
In advanced cases, the fingertips may become rounded and swollen (clubbing), and the chest shape may change due to long-standing lung disease.
Diagnostic tests
Because this disease is rare and complex, diagnosis is usually done in a special center that has experience with primary ciliary dyskinesia. No single test is perfect, so doctors combine history, exam, and several tests to confirm the problem and find the specific microtubular transposition defect.
Physical exam tests
1. Full general physical examination
The doctor looks at the whole body. They check breathing rate, oxygen level, growth, weight, and signs of long-term lung disease such as clubbing or chest wall changes. They also ask about symptoms starting from birth. This basic exam helps decide how severe the disease is and what further tests are needed.
2. Detailed lung and chest examination
Using a stethoscope, the doctor listens to both lungs. They may hear crackles, wheezes, or other abnormal sounds that suggest chronic infection and bronchiectasis. They also look for signs of hyperinflation or chest deformity caused by long-term lung damage.
3. Ear, nose, and throat (ENT) examination
The doctor looks inside the nose, throat, and ears. They check for nasal polyps, thick mucus, inflamed sinuses, fluid behind the eardrums, or damage to the eardrum. These findings support a diagnosis of PCD when they are chronic and severe.
4. Check for situs inversus and heart position
By examining the chest and abdomen, and sometimes by using a simple chest X-ray, the doctor can see if the heart beats more strongly on the right side and if the liver is on the left. These clues suggest situs inversus, which strongly supports PCD when combined with respiratory symptoms.
5. Growth and nutrition assessment
Height, weight, and body mass index are plotted on growth charts. Children with long-term lung disease may be underweight or grow more slowly. This helps doctors see how much the condition has affected the child’s development.
Manual and bedside tests
6. Spirometry (lung function test)
The patient blows into a machine that measures how much and how fast air can be moved out of the lungs. Patterns on spirometry can show airway obstruction, restriction, or mixed disease and help track how lung function changes over time.
7. Peak expiratory flow measurement
This simpler breathing test measures the highest flow when blowing out quickly. It is easy to repeat at home or in clinic and helps monitor day-to-day lung function, though it is less detailed than full spirometry.
8. Saccharin test for mucociliary clearance
A tiny grain of saccharin (a sweet substance) is placed inside the nose. The time it takes for the person to taste sweetness in the throat shows how fast mucus is moved by cilia. In PCD, this time is very long or the taste never appears. This is a simple way to screen for poor ciliary function.
9. Nasal nitric oxide measurement
A small tube is placed at the nostril while the person breathes in a special way. The machine measures nitric oxide gas in the nose. People with PCD usually have very low levels of nasal nitric oxide, so this test is a strong screening tool though not perfect on its own.
10. Standardized clinical scoring systems (e.g., PICADAR score)
Doctors may use simple question-based scores that include symptoms like neonatal distress, chronic cough, ear disease, and situs inversus. A high score suggests PCD and helps decide who should get advanced testing.
Lab and pathological tests
11. Blood tests for general health and infection
Basic blood tests, such as full blood count and markers of inflammation, can show ongoing infection or anemia. While they do not diagnose PCD, they help understand how much the lungs are affected and exclude other diseases like immune deficiency.
12. Sputum culture and sensitivity
The patient coughs mucus into a sterile cup. The lab grows bacteria from the sample and tests which antibiotics can kill them. In PCD, chronic infection with organisms such as Pseudomonas aeruginosa or Haemophilus influenzae is common, and culture guides proper treatment.
13. Nasal or bronchial brush/biopsy for ciliary samples
A small brush or tool is used to take a tiny sample of ciliated cells from the nose or airway. This is usually quick and safe. The sample is used for video microscopy, electron microscopy, and sometimes cell culture. This step is central for seeing the microtubule transposition defect.
14. High-speed video microscopy analysis of ciliary beat
Under a special microscope with a high-speed camera, doctors watch how the cilia move in the sample. In this disease, cilia may show disorganized, stiff, or abnormal beating patterns that match the underlying structural defect.
15. Transmission electron microscopy (TEM) of cilia
This is the key test to see the microtubular transposition. The biopsy sample is prepared and examined with an electron microscope that can see the microtubules inside each cilium. Doctors can then identify the abnormal pattern, such as an outer doublet moved into the center, and use standardized criteria to report this defect.
16. Immunofluorescence staining of ciliary proteins
Lab specialists can stain cilia with fluorescent antibodies that attach to specific structural proteins. If certain proteins are missing or in the wrong place, this supports a diagnosis of PCD and can point to which gene is involved.
17. Genetic testing for PCD-related genes
Blood or saliva is sent to a genetic lab. They look for known pathogenic variants in many PCD genes at once. A positive result can confirm the diagnosis, explain the microtubular transposition defect, and help with family counseling, though some patients still have no mutation found.
18. Semen analysis in males
For adult males with fertility problems, a semen test checks sperm count and motility. In this disease, sperm may move poorly because the tail has a similar structure to cilia with microtubules. This supports the diagnosis but is not used in children.
Electrodiagnostic-type tests
19. Pulse oximetry and sometimes electrocardiogram (ECG)
A small clip on the finger measures oxygen saturation to see how well the lungs are working. An ECG records the heart’s electrical activity to check rhythm and strain, especially if there is lung disease or congenital heart defects with situs abnormalities. These tests do not diagnose PCD, but they help assess overall cardio-respiratory status.
Imaging tests
20. Chest X-ray
A simple chest X-ray can show signs of lung infection, hyperinflation, bronchiectasis, and heart position. It may reveal dextrocardia (heart on the right) and other hints of situs inversus, which raise suspicion for PCD in the right clinical setting.
21. High-resolution CT (HRCT) of chest and CT of sinuses
HRCT is a detailed scan that shows the airways and lung tissue clearly. It is the best imaging method to see bronchiectasis and mucus plugging in PCD. A CT scan of the sinuses reveals thickened mucosa, blocked drainage pathways, and chronic changes. These scans are important to document the extent of disease and to guide treatment, even though they do not show the ciliary microtubules directly.
22. Echocardiography and abdominal ultrasound
An ultrasound of the heart (echo) and abdomen can show where the heart and organs are located and if there are any structural heart defects. This helps confirm situs inversus or other laterality problems that often accompany PCD and supports the overall diagnosis when combined with lung and cilia findings.
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: January 26, 2025.
