Ondine's curse

Etymology
According to French and German mythology, the nymph Ondine/Undine discovered that her husband had committed adultery. Because he had promised his every waking breath to her, she cursed him that so long as he was awake he could breathe, but if he ever fell asleep he would stop breathing and die.

Proper noun

 * 1)  A medical condition marked by malfunction of the nerves that control involuntary body functions, causing breathing to require conscious effort and therefore meaning patients will die if they fall asleep.

Usage notes
The medical term for the condition is or  or.

Translations

 * French: syndrome d'Ondine
 * German: Undine-Syndrom
 * Polish: klątwa Ondyny
 * Portuguese: maldição de Ondina