CCHS stands for Congenital Central Hypoventilation Syndrome. Congenital means that you are born with the condition. Central hypoventilation means that the hypoventilation (under breathing) is due to a disorder in the bottom of the brain, just above the back of the neck. Syndrome means a group of symptoms that consistently occur together or a condition characterized by a set of associated symptoms. CCHS is a rare lifelong and life-threatening disorder.
CCHS affects the central and autonomic nervous system which controls many of the automatic functions in the body such as heart rate, blood pressure, sensing of oxygen and carbon dioxide levels in the blood, temperature, bowel and bladder control, and more. The most recognized symptom of CCHS is the inability to control breathing that varies in severity, resulting in the need for life-long ventilatory support during sleep in some patients or all the time in others.
The underlying cause of CCHS is a germline mutation in the PHOX2B gene. Most children with CCHS (90%) have mutations of the PHOX2B gene called poly-alanine repeat expansion mutations (PARMs). Some children with CCHS have different mutations in the PHOX2B gene not related to PARMs called non-poly-alanine repeat expansion mutations (NPARMs). Both PARMs and NPARMs lead to impaired function of the PHOX2B protein. Most mutations occur de novo (new) in CCHS patients, but 5 to 10% are inherited from a mosaic typically unaffected parent. Incomplete penetrance has been demonstrated when certain PHOX2B mutations are present in all the cells (including the reproductive cells of the germline) of individuals known to be unaffected.
CCHS is a rare disorder that affects females and males in equal numbers. Though the mutation is already present before birth, in milder cases the diagnosis may be missed until after the newborn period. Some affected individuals will not be identified until after receiving sedation, anesthesia, or anti-seizure medications, making it especially important to educate health care personnel about CCHS and to have a high index of suspicion for considering a diagnosis of CCHS. As of 2013, more than 1,000 cases are known worldwide. The birth prevalence of CCHS has been extrapolated from incidence figures and general birth rates, but the true prevalence is unknown as culturally diverse large population based studies have not been reported.
Unfortunately, Ondine’s Curse was the name given to the condition in 1962. This name comes from a German legend in which the nymph, Ondine, placed a curse on her unfaithful mortal husband, removing all his body’s automatic functions which forced him to remember to breathe. When he went to sleep, he stopped breathing. When early physicians saw CCHS babies stop breathing when asleep they coined the term Ondine’s Curse for the condition. In recent years this term has been disavowed by the CCHS Community, in favor of CCHS.
Most individuals with CCHS do not stop breathing altogether, but do not breathe deeply enough to support body functions.
Early detection and management of CCHS with adequate ventilation and appropriate therapies have helped CCHS patients live fulfilling lives. Proper management has allowed CCHS patients to seek higher education, enter the work force and have families of their own.
The health implications of the PHOX2B mutation do vary within and across the mutations, where some patients achieve at normal or higher levels while others may struggle with academic challenges or significant associated medical issues affecting the bowels, eyes or growth issues. It is important to work with your medical team to optimize CCHS management.
The CCHS Network works to fund research leading toward curative treatments through its CCHS Foundation.