What is Congenital Central Hypoventilation Syndrome

Congenital Central Hypoventilation Syndrome (CCHS) is a rare, life-long disorder of the autonomic nervous system that causes an individual to hypoventilate, or breathe too shallowly and infrequently, particularly during sleep. Because the brain’s automatic signal to breathe is impaired, patients with Congenital Central Hypoventilation Syndrome require lifelong ventilatory support to ensure adequate oxygen levels and carbon dioxide removal.

What exactly is Congenital Central Hypoventilation Syndrome?

Congenital Central Hypoventilation Syndrome is often referred to as "Ondine’s Curse." It is a rare disorder characterized by a failure of the autonomic nervous system to control breathing automatically. While most people breathe without thinking, individuals with Congenital Central Hypoventilation Syndrome must consciously exert effort to breathe, or rely on mechanical ventilation. Beyond breathing, the condition affects the autonomic nervous system, which regulates involuntary functions like heart rate, blood pressure, and bowel motility.

How does Congenital Central Hypoventilation Syndrome affect the body?

The primary impact of Congenital Central Hypoventilation Syndrome is on the respiratory drive. However, because the autonomic nervous system is involved, patients may experience a wide range of systemic issues. Key features often include:

• Respiratory Failure: Inadequate breathing, most severe during sleep, requiring tracheostomy or non-invasive ventilation.


• Dysautonomia: Irregular heartbeats, episodes of profound bradycardia (slow heart rate), and poor temperature regulation.


• Gastrointestinal Issues: Many patients experience Hirschsprung disease, a condition where the nerves in the bowel are missing, leading to severe constipation.


• Neurological/Cognitive Effects: Potential for developmental delays or learning disabilities if the brain experiences prolonged periods of low oxygen (hypoxia).


• Tumor Susceptibility: An increased risk for developing neural crest tumors, such as neuroblastoma or ganglioneuroma.

What causes Congenital Central Hypoventilation Syndrome?

Congenital Central Hypoventilation Syndrome is primarily caused by a mutation in the PHOX2B gene. This gene is essential for the development of the autonomic nervous system. Most cases occur as a "de novo" mutation, meaning it is not inherited from parents, though it can be passed on in an autosomal dominant pattern. The specific type of mutation—often an expansion of polyalanine repeats—correlates with the severity of the symptoms and the associated risks for other systemic complications.

How common is this condition?

Congenital Central Hypoventilation Syndrome is extremely rare, with an estimated prevalence of approximately 1 in 200,000 live births. Because it is often underdiagnosed or misdiagnosed as other respiratory issues, the true incidence may be higher. Currently, there are 94 people in the DiseaseMaps.org community who have shared their experiences living with the condition, highlighting the importance of connecting with others who navigate these unique challenges.

What differentiates it from other respiratory disorders?

Unlike asthma or chronic obstructive pulmonary disease (COPD), which affect the lungs or airways, Congenital Central Hypoventilation Syndrome is a "central" problem. The lungs themselves are usually healthy, but the brain's "breathing center" in the medulla oblongata fails to send the necessary signals to the diaphragm and chest muscles. This distinction is critical because standard asthma treatments are ineffective for patients with Congenital Central Hypoventilation Syndrome.

Next steps

• Consult a pediatric pulmonologist or a neurologist specializing in autonomic disorders for diagnostic confirmation and management.


• Undergo genetic testing to identify the specific PHOX2B mutation, which helps in predicting potential long-term health risks.


• Connect with the 94 members of the DiseaseMaps.org community to share resources and emotional support.


• Establish a multidisciplinary care team, including specialists in cardiology, gastroenterology, and neuro-oncology.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Congenital Central Hypoventilation Syndrome.


• Orphanet: Rare Disease Database (ORPHA: 898).


• OMIM (Online Mendelian Inheritance in Man): Congenital Central Hypoventilation Syndrome (Entry #209880).


• CCHS Network: Patient advocacy and clinical resources for families.