Breathing can sometimes be abnormal from birth. In a rare genetic condition referred to as Ondine's curse, the breathing difficulty can be serious and even life-threatening. Explore some of the potential causes of Ondine's curse and how it can be effectively treated.

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What Is Ondine's Curse?

Ondine’s curse—more appropriately known as congenital central hypoventilation syndrome, or CCHS—is a rare, severe form of sleep apnea in which an individual completely stops breathing when falling asleep. It is always congenital, meaning that it is present from birth. There is also an acquired form of central hypoventilation syndrome that can result from brain or spinal injury or neurodegenerative diseases.

Central sleep apnea is characterized by the brainstem failing to prompt normal breathing. This seems to be due to a decreased responsiveness to high levels of carbon dioxide and low oxygen levels within the blood. This becomes especially dangerous during sleep.

Ondine’s curse is named after a mythical tale in which a heartbroken water nymph curses her unfaithful husband to stop breathing should he ever fall asleep. In medical terms, Ondine's curse represents an extreme form of sleep apnea.

Causes

Ondine's curse affects about one in 30 million people, which means only several hundred people have it in the world. As such, it is considered to be an extremely rare condition. A genetic mutation appears to be the underlying cause. It is thought to occur when the brain fails to prompt breathing, as may also be seen in central sleep apnea.

When the condition is present from birth, Ondine's curse may be associated with difficulty swallowing, intestinal problems called Hirschsprung’s disease, or tumors called neuroblastoma. Both the congenital and acquired forms can cause symptoms related to low oxygen during sleep, including shallow breathing while sleeping, cyanosis in the fingers or toes, seizures, heart abnormalities, and cognitive difficulties. The congenital form almost always presents in the newborn period, while the non-congenital form happens later in life (for example, after spinal cord surgery or with brainstem tumors or strokes). CCHS can also be associated with other disorders, including tumors of the nervous system (neuroblastomas, ganglioneuromas, ganglioneuroblastomas), eye abnormalities, and characteristic facial features (short, wide, flattened face), whereas the acquired type is not.

Though the condition usually occurs sporadically, there may be a genetic tendency that runs in families. Relatives may have a milder form of dysfunction that affects the autonomic nervous system.

In 2003, the PHOX2B gene was identified as the disease-defining gene for CCHS, providing pathologists the means to definitively diagnose this disease and provide early treatment.﻿﻿ In about 10% of cases, other mutations at the same location are involved. Parents who wish to have additional children after having a child with CCHS are encouraged to seek genetic counseling.

Symptoms

Most affected individuals have an onset shortly after birth, though cases have also been diagnosed in utero. Symptoms may appear in milder cases with the use of anesthesia or sedatives.

People with CCHS take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood.

Reduced and shallow breathing is most apparent in non-REM sleep but can even occur during REM sleep or when fully awake, albeit to a lesser degree.

Other symptoms include acid reflux and poor upper gastrointestinal motility, which manifests with nausea, pain, dysphagia (difficulty swallowing), and vomiting.

Treatment

Treatment involves the use of a mechanical ventilator connected to a tracheostomy tube in front of the throat. The ventilator ensures normal breathing whenever the person goes to sleep, even during naps. If this were not used, someone with CCHS could die anytime they fall asleep.

Reflux is often treated with medications, while poor upper gastrointestinal motility may often be managed with diet and altered eating habits.

Due to the nature of the treatment, families of those afflicted often become adept at managing the equipment required to maintain normal breathing. It may initially seem intimidating, but help within the hospital setting allows a smooth transition to treatment at home. Guidance from respiratory therapists, including possible at-home assistance, can ease this adjustment.

A Word From Verywell

If you are interested in learning more about Ondine's curse, especially if you have an affected child, it is recommended that you consider a consultation with a pediatric pulmonologist at an academic medical center.

Due to the rarity of the condition and the seriousness of the potential consequences, the care of a specialist will initially be required. It may also be possible to network with other affected families who are managing the condition. This social support may be helpful for many reasons. Reach out to get the help that you need from a specialist to optimize the health and well-being of your child and family.