What Is Ciliopathy?

Ciliopathy is a broad category of disorders resulting from a defective function of the cilia, which are the microscopic, strands-like structures that coat the surface of most, if not all, cells within the human body. The disorders are said to be genetic, since they are a result of some abnormalities or mutations in a certain chromosome or gene. This also means that they can be passed down from one generation to another. Some disorders under ciliopathy are Alström syndrome, nephronopthisis, and primary ciliary dyskinesia (PCD).

The cilium, or cilia in its plural form, was discovered in the late 1800s, but its importance was underestimated, probably because of its miniscule size and its external location on the cell. Modern research, however, has shown that the existence of cilia is actually necessary for the organs to function properly. The motile or moving type of cilia, for example, helps the respiratory system filter the air so the body does not inhale many irritants. The primary or the non-motile cilia, on the other hand, serve as a “signal transmitter” for the kidney to “tell” the body that urine will be released. Defective cilia, therefore, would result in ciliophaty disorders that can impair a patient’s quality of life and can even put his life at risk.

Among the many organs in the body, the most commonly affected with ciliopathy are the eyes, the kidney, and the liver. In some cilliopathic disorders, all three organs are affected, along with the brain. One example is nephronopthisis, in which the mutated cilia cannot detect the “signal” to stop cells from multiplying, thus, kidney cysts are formed. Primary symptoms of nephronopthisis are excessive urination and water intake, while some associated or “extra-renal” symptoms are progressive blindness, excessive tissues in the liver, and mental retardation.

Another kind of ciliopathy is the Alström Syndrome, a very rare condition that involves primary organs such as the heart, liver, and the lungs. It is congenital and affects the patient from birth and can sometimes result in death in infancy. The defective cilia located in the primary organs cause general heart weakness and enlargement, impaired kidney and liver function, and obesity. Some patients may also experience photosensitivity in their eyes, leading to worse vision impairment in early adulthood.

Many diseases categorized as ciliopathy are rare, and thus have yet to be extensively studied and researched for treatment and management options. For example, only about 700 cases of Alstrom Syndrome have been documented worldwide since its discovery in 1959. More studies, however, have led scientists and doctors to believe that ciliopathy may affect one out of 1,000 people.