Primary ciliary dyskinesia, first described by Abzelius (1976), Pederson (1956) and Eliasson (1977), is autosomal recessive and is associated with visceral translocation in half of the patients, so Kartagener syndrome is now considered a type of the syndrome. The incidence is 1:16,000, which is estimated to be about twice that of Kartagener’s syndrome. The congenital abnormalities of systemic cilia include deficiencies in the power arm (containing ATPase) and deficiencies in microtubule chain loops or spokes, resulting in poor ciliary motility and impaired clearance, leading to retention of mucus secretions and bacteria, resulting in persistent recurrent infections leading to paranasal sinusitis, bronchiectasis, and bronchiectasis. The age of onset can range from infancy to adulthood, but school-age children and young adults are the most common. Pathogenesis: Each ciliated epithelial cell surface of the respiratory mucosa has about 200 cilia about 5-10 microns long and 0.2 microns in diameter. When observed under electron microscope, the cross section of each cilium is centered on two microtubules with 9 pairs of microtubules at the periphery (9+2 type structure), with power arms, linking rings and wheel amplitude to keep them interconnected and in normal position. In immobile cilia syndrome, structural abnormalities of cilia, such as absence of power arm, defective wheel width, and abnormal arrangement of microtubules, can cause respiratory cilia paralysis, cilia mucus transmission dysfunction, and the formation of chronic recurrent purulent pulmonary inflammation, sinusitis, otitis media, and male infertility (Figure). Clinical manifestations: Commonly seen in children and young adults, the main manifestations are as follows. 1. Lower respiratory manifestations: patients have recurrent episodes of episodes of sensitization, chronic bronchitis or interstitial pneumonia and bronchiectasis, with cough, yellow pus sputum, hemoptysis and dyspnea. This leads to pulmonary atelectasis and bronchiectasis, with symptoms such as cough, yellow pus sputum, hemoptysis and dyspnea. 2. Upper respiratory manifestations: Patients often have chronic rhinitis and sinusitis, which cause mucus or purulent secretion retention in the sinuses, so there is nasal congestion, pus, and sometimes nasal polyps. Due to abnormal middle ear and eustachian tube cilia, it can lead to chronic recurrent otitis media. 3. Visceral inversion: During the embryonic period, due to abnormal cilia structure, certain epithelial tissues lose their normal oscillation, so that the directional rotation of the viscera becomes random rotation. For example, at 10-15 days of gestation, the viscera should rotate to the right under normal circumstances, but instead they rotate to the left, thus forming visceral retroposition. 4. Infertility: The sperm tail is a variant of cilia, and when its structure is abnormal, the sperm loses its oscillating ability, which can cause male infertility. Diagnosis and differential diagnosis: Bronchial dilatation, sinusitis and visceral displacement can be diagnosed based on chest X-ray plain film, bronchogram, sinus X-ray plain film and CT scan. Nasal and bronchial mucosal biopsies with cilia abnormalities seen under electron microscopy can lead to a positive diagnosis. The disease should be differentiated from chronic respiratory tract infections, bronchiectasis. Bronchial asthma can also occur with abnormal mucus and cilia function, but there are no specific defects in cilia structure. Treatment: Enhance physical fitness and prevent respiratory infections. Treatment of recurrent respiratory tract infections with anti-infectives and drugs that promote sputum elimination. Those with limited lesions and indications for surgery should be promptly treated surgically. Attention should also be paid to the treatment of sinusitis. Prognosis: The prognosis of this disease is good with limited lesions and satisfactory surgical results. The disease should be prevented by promoting the elimination of mucus secretions, anti-infection and symptomatic treatment. The disease has a good prognosis and has no impact on life expectancy despite chronic respiratory disease. Ultrastructural illustration of cilia: 1. normal 2. defective power arm 3. defective whorl width 4. defective whorl width and abnormal arrangement of microtubules D. power arm C. central microtubule O. peripheral microtubule S. whorl width