Chapter 217: Primary Ciliary Dyskinesia

Patient Story

A 13-year-old boy presents for evaluation of a chronic productive cough and fever. Since birth, he has had persistent rhinitis, thick nasal drainage, and recurrent otitis media. He has been seen three times in the past year for pneumonia each time diagnosed and treated without a chest x-ray. On physical exam, heart sounds are greater on the right side and point of maximal impulse is felt in the right 5th intercostals space. A chest x-ray shows situs inversus totalis with dextrocardia (Figure 217-1). Computed tomography of the sinuses shows chronic sinusitis (Figure 217-2). The diagnosis of primary ciliary dyskinesia was considered and he underwent a biopsy of his nasal epithelium, which revealed abnormal ciliary structure and function. This confirmed the diagnosis and the physician explained the meaning of primary ciliary dyskinesia and the situs inversus to the patient and his parents. He was told that he will need aggressive treatments for all future infections.

Introduction

Primary Ciliary Dyskinesia (PCD) is a rare genetic disease associated with abnormal cilia structure and function causing impaired clearance of bacteria from the lungs, paranasal sinuses, and middle ear, which leads to recurrent infections. It can be associated with other developmental abnormalities such as situs inversus totalis, nasal polyposis, and frontal sinus agenesis. Clinical manifestations include chronic cough and chronic rhinosinusitis and recurrent sinopulmonary and ear infections.

Synonyms

• Primary Cilia Disorder.

• Immotile Cilia Syndrome (ICS).

• Kartagener syndrome—A triad consisting of situs inversus with bronchiectasis and paranasal sinusitis (secondary to PCD).

Epidemiology

• PCD is inherited in an autosomal recessive pattern and occurs in approximately 1 in 10,000 to 30,000 births.^1–3

Etiology and Pathophysiology

PCD is caused by genetic mutations on genes which code for proteins found in the ciliary outer dynein arm which controls the cilia beat force and frequency.

• Motile cilia (Figure 217-3) contain a cylinder of 9 microtubule doublets, arranged around a central pair of microtubules in the characteristic “9 + 2” arrangement as viewed by cross-sectional views on electron microscopy.

• Defective cilia (Figure 217-4) resemble sensory or primary cilia, which lack a central microtubule doublet and outer dynein arms, thus creating a ...