Review Question - QID 106657

This patient's presentation is consistent with Kartagener's syndrome, which is caused by immotile cilia resulting from a dynein arm defect.

The presentation of primary ciliary dyskinesia involves chronic respiratory infections, including chronic sinusitis and bronchiectasis, as well as male infertility. The presence of situs inversus is required for the diagnosis of Kartagener's syndrome; 50% of patients with primary cilia dyskinesia have situs inversus and therefore qualify for this diagnosis. This condition demonstrates autosomal recessive inheritance.

Kinney and DeLuca review the diagnosis of Kartagener's syndrome. The triad of chronic paranasal sinusitis, bronchiectasis, and situs inversus is required for a diagnosis of Kartagener's syndrome. A chest radiograph and/or CT scan is often useful in confirming the presence of bronchiectasis as well as situs inversus. Signs of bronchiectasis on chest radiograph include bronchial wall thickening and/or bronchial dilatation with loss of normal peripheral tapering.

Leigh et al. discuss the genetic aspects of primary ciliary dyskinesia and Kartagener's syndrome. The majority of disease causing mutations in primary ciliary dyskinesia involve heavy or intermediate chain genes that make up the proteins in the outer dynein arms of cilia. Molecular genetic testing is able to identify the most common mutations.

Figure A is a chest radiograph showing situs inversus (note the dextrocardia and tram-tracking in the lower lung lobes indicative of bronchiectasis), a component of Kartagener syndrome. Illustration A reviews the pathophysiology of primary dyskinesia and how immotile cilia can lead to respiratory issues such as bronchiectasis and sinusitis. Illustration B shows the normal structure of cilia. Illustration C summarizes the difference between normal cilia (left image) and cilia in Kartagener's syndrome that lack a functional dynein arm (right image).

Incorrect Answers:
Answer 1: Chédiak-Higashi syndrome, which presents with recurrent pyogenic infections, partial albinism, and peripheral neuropathy, is caused by a microtubule polymerization defect.
Answer 2: Kinesin, the molecular motor protein that mediates anterograde transport, is not affected in Kartagener's syndrome.
Answer 3: Sphingomyelinase is deficient in Niemann-Pick disease, which presents with hepatosplenomegaly, anemia, cherry red spot macula, failure to thrive, and neurodegeneration.
Answer 5: Leukocyte adhesion deficiency is caused by an LFA-1 integrin (CD18) defect on phagocytes, which leads to recurrent bacterial infections, absent pus at the site of the infections, and delayed separation of the umbilical cord.