Snapshot A 6-year-old boy presents to his pediatrician's office due to fever, frequent sputum production, and rhinorrhea. This is the 4th time this year that he has been having these symptoms, which was previously managed with bedrest and antibiotic therapy. The patient was born at term to a 29-year-old woman via spontaneous vaginal delivery. The birth was complicated by mild respiratory distress requiring oxygen supplementation for approximately 1 week. Vital signs are significant for fever, mild tachypnea, and an oxygen saturation of 94% on room air. On physical exam, there is sinus tenderness over the maxillary sinuses and crackles and wheezes on pulmonary auscultation. A radiograph of the chest is performed, which demonstrates ring shadows, tramlines, and dextrocardia. Introduction Clinical definition an inherited disorder that affects motile cilia Epidemiology incidence ~50% of patients have situs inversus describes that the visceral organs are reversed e.g., dextrocardia demographics most cases present in childhood (~5-6 years of age) Etiology autosomal recessive mutations that affect motile cilia production or function this is a heterogenous disorder Pathogenesis mutations that impair motile cilia function results in abnormalities in organ laterality situs inversus impaired mucociliary clearance places the patient at risk of developing airway infection, disease, and distress disorders of infertility Associated conditions Kartagener syndrome characterized by patients having the triad situs inversus chronic sinusitis bronchiectasis Prognosis long-term outcomes depend on respiratory severity lifespan is typically expected to be normal Presentation Symptoms respiratory newborns may present with mild respiratory distress recurrent upper and lower respiratory infections rhinosinusitis (a cardinal feature) patients may have headache chronic secretory otitis media accompanied by recurrent acute otitis media can result in a conductive hearing loss impaired or decreased fertility ectopic pregnancy Physical exam pulmonary exam auscultatory crackles wheezes situs inversus Imaging Radiography indication performed in patients suspected of having primary ciliary dyskinesia radiography is preferred in children findings situs inversus mucoid impaction bronchiectasis Computerized tomography (CT) scan indication performed in patients suspected of having primary ciliary dyskinesia CT scan is preferred in adults findings situs inversus bronchiectasis Studies Making the diagnosis based on clinical presentation and supported by testing e.g., nasal nitric oxide measurement, high-speed videomicroscopy, and transmission electron microscopy Differential Cystic fibrosis distinguishing factor patients with cystic fibrosis will have an abnormal CFTR genetic test and sweat chloride test Treatment Management approach management is based on what is known for cystic fibrosis and bronchiectasis Complications Respiratory bronchiectasis recurrent airway infection Otolaryngology conductive hearing loss secondary to chronic otitis media Reproductive abnormal sperm motility in men abnormal cilia motility in the fallopian tubes of women may result in ectopic pregnancy