PRIMARY CILIARY DYSKINESIA (PCD)

Congenital heterogeneous disorder with an estimated prevalence of 1:10,000, higher in consanguineous populations. As many patients are believed to remain undiagnosed, it is thought that the correct prevalence of the disease is still unknown.

This disorder leads to chronic respiratory infections, usually beginning at birth with respiratory distress followed by a wet cough in early childhood and evolving to include bronchiectasis and chronic sinusitis. The earlier it is diagnosed the better prognostic the patients will have.

As half the PCD cases are associated with situs inversus and heterotaxy, this disorder is not just respiratory and can have a high correlation with congenital heart disease. Male sterility is also common in adults, since sperm flagella are motile cilia and may also present defective motility.

PCD is characterized by deficient mucociliary clearance, which is caused by one or several factors, such as lack of motile cilia, uncoordinated ciliary pattern or total lack of ciliary motion. This disorder usually follows an autosomal recessive heritance pattern, with more than 40 genes found to cause it when mutated.