Central Alveolar Hypoventilation Syndrome (CAHS), also known as Ondine's Curse or Congenital Central Hypoventilation Syndrome (CCHS), is a rare genetic disorder that affects the autonomic control of breathing. It is characterized by a reduced ability to adequately ventilate the lungs due to abnormal responses from the central respiratory centers in the brain.
Individuals with CAHS typically have normal breathing patterns when awake and conscious. However, during sleep or unconsciousness, they exhibit shallow breathing or periods of apnea, where breathing completely stops. This apnea can lead to decreased oxygen levels and increased carbon dioxide levels in the blood, which can have detrimental effects on multiple organ systems in the body.
CAHS is typically caused by a mutation in a gene called PHOX2B, which plays a crucial role in the development and function of the autonomic nervous system. This mutation leads to an impaired response of the brainstem respiratory centers to elevated carbon dioxide levels, resulting in insufficient ventilation during sleep.
Symptoms of CAHS may include daytime sleepiness, morning headaches, difficulty concentrating, and impaired exercise tolerance. If left untreated, CAHS can lead to life-threatening complications such as respiratory failure and cardiac arrhythmias.
Treatment for CAHS involves the use of positive airway pressure devices, such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP), which help maintain adequate ventilation during sleep. In some cases, assisted ventilation may be necessary to support breathing. Genetic counseling and regular monitoring are essential for individuals with CAHS and their families.
