29 September 2020
A newly-identified congenital lung disease
Published online 30 April 2014
The cells that line the surface of the respiratory tract are covered by motile cilia known as multiple motile cilia (MMC). They beat back and forth in synchrony to clear the airway of inhaled particles and pathogens in a process called mucociliary clearance.
Decreased ciliary motility is a key contributor to a range of mucociliary clearance disorders. A team of international researchers led by Heymut Omran of the University Hospital Muenster in Germany have identified a new form of mucociliary clearance disorder. The team found that recessive mutations in a gene called CCNO resulted in a severe decrease in the number of MMC at the surface of respiratory epithelial cells in 16 patients and determined the reason behind it, publishing their findings in Nature Genetics (published online 20 April 2014).
In vitro experiments on primary respiratory epithelial cells showed that the reason for the severe reduction in the number of MMC was because fewer MMC had been generated; secondary causes were not the reason for fewer MMC. A pronounced decrease in basal bodies (basal bodies play a role in ciliary movement) in CCNO mutants as well as evidence for failure of basal bodies to be positioned correctly in the cytoplasm was also noted.
This newly-characterized chronic lung disease causes recurrent respiratory symptoms that can lead to lung failure. "We believe many children and adults with chronic destructive airway disease might suffer from this novel disease, because unfortunately current diagnostics missed this disease," says Heymut Omran. He suggests that genetic testing could help with early diagnosis and treatment with antibiotics and airway cleaning techniques.
- et al. Mutations in CCNO result in congenital mucociliary clearance disorder with reduced generation of multiple motile cilia. Nature Genetics (2014) doi:10.1038/ng.2961