Primary alveolar hypoventilation syndrome (PAHS) is a rare disorder which shows hypoxemia and hypercapnia without apparent associated pulmonary, neuromuscular, and central nervous diseases. PAHS is characterized by exacerbation of hypoxemia during sleep. Disorders of both automatic and chemical control of ventilation are considered as causes of this syndrome. PAHS occurring during infancy is called congenital central alveolar hypoventilation syndrome (CCHS). Although the relationship between CCHS and adult onset PAHS is unclear, the familial occurrence of PAHS may suggest an underlying genetic mechanism. It has been represented that some adult onset PAHS may be a mild type of CCHS. Recently, noninvasive positive pressure ventilation (NIPPV) has become available for PAHS.
