Congenital Central Hypoventilation Syndrome
Congenital central hypoventilation syndrome (CCHS) is a genetic condition often appearing at birth in which the brain fails to properly control breathing to maintain healthy levels of oxygen and carbon dioxide. This hypoventilation — a decrease in the rate and/or depth of breathing — causes the child's oxygen values to decrease and the carbon dioxide values to increase.
This occurs during sleep in all cases of CCHS and, in many cases, during wakefulness as well. Mechanical ventilation with a respirator is usually needed, though in some cases diaphragm pacing may be useful.
What Are the Symptoms of Congenital Central Hypoventilation Syndrome?
Even though CCHS is congenital, the symptoms may not be apparent at birth especially if the symptoms are mild. Consequently, a small number of cases are being found in later infancy, childhood and even adulthood.
An individual with CCHS also has a poorly regulated autonomic nervous system, a system in the body that regulates not only breathing but also heart rate, sweating, temperature regulation, pupil size and more. The problem can also slow the motility of the esophagus, small and large intestine, so that food moves much too slowly down the esophagus to the stomach and also through the intestine, which can sometimes cause severe constipation.
Patients with CCHS and the more prevalent polyalanine repeat expansion mutation have characteristic facies immediately identifiable from photographs. Some patients with CCHS have a tumor of neural crest origin: neuroblastomas in many of the children with a non-polyalanine repeat expansion mutation and ganglioneuroma or ganglioneuroblastoma in a very small subset of children with the longer polyalanine repeat expansion mutations.
In some cases of CCHS, children are missing ganglion cells in their intestine, resulting in an anatomic reason for the slowed intestinal motility — a condition known as Hirschsprung disease (megacolon). The heart rate may also be abnormally slow. When the heart rate indicates pauses of three seconds or longer, children with CCHS need a cardiac pacemaker.
Though CCHS has been identified in children of all races, most reported cases are Caucasian. Both sexes appear to be equally affected.