Learning Objectives

• Define the genetic and structural basis of Primary Ciliary Dyskinesia (PCD).
• Identify the clinical triad of Kartagener Syndrome.
• Explain the multi-system complications involving respiratory, reproductive, and developmental systems.
• Master the laboratory screening methods for diagnosis.

1. Pathophysiology

PCD is an autosomal recessive disorder characterized by a dynein arm defect. Because dynein is the “motor” that allows ciliary doublets to slide and bend, its absence results in immotile cilia and dysfunctional ciliated epithelia.

2. Clinical Presentation: Kartagener Syndrome

The most recognizable form of PCD is Kartagener Syndrome, which occurs when PCD is paired with situs inversus (total reversal of organ positions).

• Developmental Abnormalities: Impaired ciliary signaling during embryogenesis leads to Situs inversus and hearing loss (due to dysfunctional eustachian tube cilia).
• Recurrent Infections: Lack of effective ciliary clearance leads to chronic sinusitis, frequent ear infections, and bronchiectasis (permanent dilation of bronchi due to chronic inflammation).
• Infertility:
  • Males: Immotile spermatozoa (flagella are structurally identical to cilia).
  • Females: Dysfunctional fallopian tube cilia increase the risk of ectopic pregnancy.

3. Diagnosis & Lab Findings

Early screening is vital for managing chronic respiratory symptoms.

• Nasal Nitric Oxide: Patients with PCD typically have decreased () nasal nitric oxide levels, which serves as a highly effective screening test.
• Electron Microscopy: Used to definitively visualize the missing dynein arms in a biopsy of ciliated tissue.

4. PCD vs. Cystic Fibrosis (CF)

Both present with recurrent sinopulmonary infections and bronchiectasis. However, situs inversus and immotile sperm (vs. absent vas deferens in CF) are key clues that point toward PCD/Kartagener.

Activity