Ondine’s Curse and Daphne’s Miracle

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Watch Daphné Spence clamber over chairs and run about a room and there is little reason to suspect that this pig-tailed toddler, decked out in pink and carrying a Pokémon backpack, is different than any other child. But for the first 27 months of her life she was unable to breathe on her own.

When Daphné was one-week-old she was diagnosed with Ondine’s disease, a rare neurological disorder, where the signal to breathe is never generated by the brain or transmitted to the diaphragm, the major muscle that drives breathing. She was given a tracheotomy-a surgical opening in her windpipe-that allowed doctors to hook her up to a respirator, which kept her alive.

The problem with the respirator was that it couldn’t keep up with Daphné as she grew. As she learned to stand and walk, she toddled about, enjoying her newfound mobility, lugging the respirator behind her. Until now, Daphné spent very little time separated from her respirator; brief moments where she could crawl, climb and run like any other two-year-old.

Now, thanks to surgeons at The Montreal Children’s Hospital (MCH) of the McGill University Health Centre (MUHC) and a pacemaker the size of a pack of cards, Daphné is able to breathe without a respirator for the first time.

In November, Dr. Helene Flageole, a pediatric surgeon at the MCH, connected two nerve pacers to the phrenic nerve that runs from the base of Daphné’s brain (the brain stem) to her diaphragm. A transmitter, which Daphné carries in her Pokemon knapsack, triggers the pacer to stimulate the nerve about 25 times each minute-the average breathing rate for a two-year-old.

“It is a control problem,” says Flageole. Daphné’s phrenic nerve is intact and works fine, but the cells in the brainstem that control it are abnormal or non-functioning, meaning that the message to breathe is never generated by the brain cells.

“Now she can be a star and run down the hallway to her mother,” says Michael Davis, a physician in the division of pediatric respiratory medicine at The Children’s.

“No one else in Canada is doing this kind of surgery,” says Flageole. Daphné’s operation was one of eight $75,000 (U.S.) operations done at the hospital in the last decade. The device needs to be reset every six months to a year, to adjust the child’s breathing rate as she grows. But it cannot adjust to her day-to-day oxygen requirements.

“This is the youngest we’ve done on a pacemaker. The oldest is 20 and has paced for three years,” says Davis.

Only one company manufactures the device that gained notoriety when actor Christopher Reeve required one to be implanted after he became quadriplegic following a fall from a horse. Physicians are concerned that this orphan technology may, someday, be unavailable to the children who need it for the rest of their lives. Approximately 800 children live with Ondine’s disease.

The condition is named after a female water sprite that fell in love with a knight, condemned to die by forgetting to breathe should he be unfaithful. Last year French scientists found that patients with Ondine’s disease carried a mutation in a gene called Phox2B. The parents do not carry the mutation, meaning it must occur during fetal development.

“Finally Daphné has her liberty,” says Guandalina Auclair, Daphné’s mother. “We were told that Daphne would be on the respirator. Now she can climb and run around waving her hands. She is so excited.”