Primary ciliary dyskinesia associated with a novel microtubule defect in a child with Down's syndrome

We present a child with Down's syndrome, bilateral lower lobe bronchiectasis, sinusitis, and severe ear disease who was found to have a novel ciliary defect, with a frequent, partial absence of the walls of the A subunits of some peripheral doublets. The defect caused the A subunits to be "U-shaped" rather than "O-shaped." A nuclear nasal mucociliary transport study confirmed that this defect was associated with abnormal mucociliary transport. The ciliary defect was not observed in a biopsy performed in a second patient who had Down's syndrome.