Chemosensitivity recovery in Ondine's curse syndrome under treatment with desogestrel

Congenital central hypoventilation syndrome (CCHS), or Ondine's curse syndrome, is a rare genetic disorder associated with mutations of the PHOX2B gene. It is characterized by sleep-related life-threatening hypoventilation that requires mechanical ventilation. The ventilatory response to hypercapnia and hypoxia is absent or dramatically reduced. Spontaneous or pharmacologically induced recovery has never been reported.We have fortuitously observed a case of CO2-chemosensitivity recovery in a woman with CCHS who took a progestin contraceptive - desogestrel. We hypothesized that the desogestrel could be responsible for this effect. We tested this hypothesis in a second adult patient. Her lack of CO2-chemosensitivity was documented 5 months before she was prescribed desogestrel. Three weeks after initiation of the treatment she exhibited a ventilatory and sensory response to hypercapnia. This response persisted 3 weeks later.This is the first documented case of pharmacologically restored chemosensitivity in CCHS. It suggests that a very potent progestin such as desogestrel could unveil latent chemosensitive neural circuits.