The most common clinical problems encountered in PCD are related to the upper (ears and sinuses) and lower (lungs) respiratory systems. However, people with PCD may experience problems related to congenital malformation of the abdominal and thoracic (chest) organs. The following links are provided for additional information:
Situs Inversus and Organ Orientation
It is believed that the motion of cilia may play a part in determining the placement of organs within the thoracic and abdominal cavities. In the absence of ciliary motion, organ placement becomes a random event, giving each affected embryo a 50/50 chance of having typical placement (known as situs solitus), mirror-image placement with reversed organs (known as situs inversus) or an unusual pattern of unique organ development or placement (situs ambiguous or heterotaxy). Evidence suggests that this is precisely the case, with approximately 50% of PCD patients presenting with situs solitus and the remaining patient population having either situs inversus or situs ambiguous/heterotaxy.
‘Kartagener syndrome,’ is an older term commonly used to describe PCD with situs inversus. Since this presentation is just one of three possible organ placement scenarios in PCD, the term ‘Kartagener’s’ is somewhat limiting. Nevertheless, it persists because it has been in the medical literature for over a century. Individuals with PCD and situs solitus or PCD with situs ambiguous do not have ‘Kartagener syndrome’ as the term is only used for PCD with situs inversus.
Situs ambiguous/heterotaxy syndromes can result in very serious clinical complications, including complex congenital heart defects and defects of the spleen.
Polysplenia literally means "many spleens" (or, more accurately, partial spleens called 'splenules'). The spleen plays an important role filtering and storing blood and helping to clear bacteria from the blood stream. An increased incidence of polysplenia (frequently associated with cardiac and liver defects) has been reported in patients with situs ambiguous. Typically, splenic function is preserved in polysplenia. In rare cases, however, there is not enough functioning splenic tissue in the ‘splenules,’ resulting in a condition known as ‘functional asplenia’ (asplenia is the congenital absence of the spleen, also seen, but much more rarely in PCD). In extreme cases of splenic dysfunction, surgical repair or removal of the spleen is required.
Congenital heart defects
Congenital malformations of the heart are a rare consequence of PCD, most frequently associated with situs ambiguous/heterotaxy. Defects in the wall (septum) separating the atria or ventricles (chambers of the heart) have been reported, as well as multiple complex cardiac malformations. At times, these can be life-threatening and require immediate surgical attention.
There is evidence to suggest that hydrocephalus may be more common in individuals with PCD. Hydro (meaning ‘water’) and cephalus (meaning related to the brain or head) is a condition where excess cerebrospinal fluid in the ventricle so the brain causes them to become enlarged. If not corrected, brain damage can result. Ventriculomegaly, where the ventricles are enlarged, but there is no excess fluid, has also been reported rarely in PCD.
The ventricles of the brain are openings in the center of the brain that are lined with ciliated tissue. In animal models of PCD, hydrocephalus is quite common and often very severe. It is believed that failure of ciliary activity in the ventricles contributes to faulty drainage, allowing excess fluid to build up. These more severe cases of hydrocephalus are rarely seen in humans with PCD, though, possibly because as upright walkers, gravity provides us with drainage assistance that lower animals do not have.
Sterility and sub-fertility are common manifestations of PCD. Male infertility used to be considered universal, but there are reports of male PCD patients with normal reproductive capabilities. Females may experience sub-fertility and/or an increased risk for ectopic (tubal) pregnancy, although many women with PCD have not had problems conceiving a pregnancy naturally.
Subfertility in PCD is a mechanical issue—a matter of being unable to get the necessary reproductive components where they need to be. This should be distinguished from ‘sterility,’ which implies that the components themselves are not viable. Because most people with PCD have sperm and egg cells that are perfectly fine, just unable to travel due to ciliary inactivity, IVF and other assisted reproductive services have been used with a high level of success in PCD.