List of causes of Ondine's curse. Following is a list of causes or underlying conditions (see also Misdiagnosis of underlying causes of Ondine's curse) that could possibly cause Ondine's curse includes: Persons who have CCHS get it at birth, or develop it due to severe neurological trauma/damage to the brainstem.
In real life, Della (Barbara Hale) was married and Perry (Raymond Burr) was gay. So, no, they were not an item on the show or behind the scenes.
As Doofenshmirtz turns on his-inators, Carl tells him not to use them all at once. He does not hear, and they all go off. In the center of their beams, stands Perry. Perry is hit by all of the-inators at once. In a flash, Perry is gone, and no one knows where he is.