Relevance of the Ciliary Ultrastructure in Primary and Secondary Ciliary Dyskinesia: A Review

Primary ciliary dyskinesia is a group of autosomal recessive inherited disorders characterized by the absence of any mucociliary transport. In the cilia of most patients specific ultrastructural abnormalities are present, such as the dynein deficiency, the spoke deficiency, and the absence of the central pair of microtubules. Secondary ciliary dyskinesia, the acquired (infectious, toxic, or inflammatory) form, is mostly correlated with other abnormalities, such as microtubular abnormalities and compound cilia. However, the great overlap, the missing links, and the confusing observations limit the insight in pathogenesis and pathophysiology and may require new in vitro systems.