Supernumerary microtubules in the cilia of two siblings causing "immotile cilia syndrome".

The function and ultrastructure of nasal cilia in 2 siblings with unexplained chronic sinusitis and bronchitis were investigated. Both patients lacked nasal mucociliary clearance (greater than 30 min). On electron microscopy, the ultrastructure of nasal cilia showed an extra doublet or supernumerary microtubules with disorganized microtubular network. Other axonemal components were normally present. It is conceivable that an "extra" component of the axoneme may be added to those "defects" already recognized as a cause of the "immotile-cilia syndrome".