Primary ciliary dyskinesia (PCD) is a hereditary condition characterized by abnormal cilia, tiny hair-like structures on certain cells.
These cilia, which usually move fluids and particles, malfunction in PCD, leading to respiratory issues, chronic cough, and lung infections. Individuals with PCD often suffer from nasal congestion, wheezing, and frequent sinus infections. PCD can cause infertility due to abnormal sperm motility in males and fallopian tube issues in females, sometimes resulting in ectopic pregnancies. Nearly half of PCD patients have misplaced internal organs, like the heart on the right side instead of the left, and some may have additional organ abnormalities. Treatment focuses on managing symptoms, involving respiratory clearance techniques, antibiotics for infections, and, in severe cases, lung transplantation. Assisted reproductive technology can aid with fertility issues, and the misplacement of organs generally does not require treatment unless it causes dysfunction.
PCD is caused by pathogenic (disease-causing) variants in the DNAH5, DNAI1, or DNAI2 genes and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 200 chance to be a carrier for the DNAI2 gene.
Another name for this condition is immotile cilia syndrome.