Alagille syndrome is a genetic disorder characterized by certain defects of the liver, bones, and heart, sometimes affecting other systems of the body as well. Depending on the severity of the disorder, it can present in early infancy and childhood. The gene mutation that causes Alagille syndrome is a dominant gene, meaning that the presence of the mutation in only one parent is sufficient to pass the disorder on to a child. This disorder is very rare, occurring in approximately one out of every 85,000 births.
The disorder varies widely in its severity, even within the same immediate family. It is even possible for the disease to go almost unnoticed. At the other end of the spectrum, liver or heart transplants may be necessary for some with Alagille syndrome. One of the first symptoms that presents as part of this disorder is infant jaundice, coupled with poor development in the first three months after birth. This is an early indication that liver problems have developed. If Alagille syndrome is present, a biopsy will usually indicate that the liver has too few bile ducts.
Heart problems, particularly the presence of a hole between the left and right ventricles, are also common. A spinal x-ray may also reveal that the vertebrae have an unusual butterfly shape. As uncommon as this is in general, this rarely presents a problem for the functioning of the spinal cord and the nerves which branch off from it.
As is the case with many genetic disorders, people with Alagille syndrome sometimes have noticeably similar facial features. Problems with the kidneys and central nervous system, including retardation and developmental disabilities, may be present in severe cases as well. A specific abnormality of the eyes occurs in most children with Alagille syndrome, namely that of a circular line on the cornea that can be observed during an eye examination.
There is no known cure for Alagille syndrome, and most treatments focus on reducing problems associated with decreased liver function. Medications which compensate for decreased heart function are also common, as are multivitamin supplements, because the absorption of some vitamins is inhibited by reduced bile flow in the liver. Surgical treatments may be pursued as well, depending on the severity of the condition. Apart from heart and liver transplants, surgery to widen the pulmonary arteries may be done, both to increase blood flow and oxygenation, as well as to reduce some of the pressure placed on the heart valves by the narrowness of the arteries.