Rare respiratory disease much more common than scientists thought

INDIANAPOLIS, Ind. — Primary ciliary dyskinesia, or PCD, is a genetic disease affecting the respiratory system. Left untreated, PCD can cause a number of serious issues including chronic coughing and congestion, recurring respiratory and ear infections, and even severe lung damage. Up until now, doctors considered PCD very rare, but researchers from the Indiana University School of Medicine say it’s actually much more common than previously thought.

The research team set out to attain a clearer understanding of PCD’s global prevalence and genetic variance. So, they analyzed unique genetic sequences taken from 180,000 people and searched for 29 distinct genes linked to autosomal recessive PCD. Previous estimates show that PCD usually occurs in roughly one in 16,000 people. This latest work concludes PCD is much more common, actually developing within one in 7,500 people.

“This is very important for clinicians. Since PCD has been thought of as a rare disease, they might not recognize it when they see a patient with PCD symptoms,” says study leader Professor Benjamin Gaston, MD, who is also the Vice Chair of Translational Research in the Department of Pediatrics, in a university release. “They may think, ‘Well, it’s unlikely because it’s such a rare disease.’ But actually, it’s not anywhere near as rare as we thought.”

Are certain races more vulnerable to PCD?

The team also analyzed PCD disease prevalence among seven specific ethnic groups. Notably, individuals of African descent appear to be more vulnerable to PCD, followed by non-Finnish Europeans and Hispanics.

Among the 29 analyzed genes, study authors note that the specific gene variants causing PCD actually fluctuated between ethnicities. They hope these findings can help make it easier for doctors all over the world to diagnose and treat PCD.

“My hope is that clinicians will have a much lower threshold for evaluating people who might have PCD,” Dr. Gaston concludes.

The findings appear in The Lancet – Respiratory Medicine.