At the same time, they began calling transplant centers in New York, because it is reachable by nonstop flights from Israel. The first to respond was NewYork-Presbyterian Morgan Stanley Children’s Hospital. The two medical teams on opposite sides of the Atlantic began a steady stream of e-mail and phone calls in hopes of stretching the limits of medicine and America’s transplant system to save the life of a girl with a deadly form of a rare disease.

Kara Ventura, a nurse practitioner and transplant coordinator in New York, answered the call from Dr. Gadi Lalazar, in Hadassah’s liver unit, about 3 a.m. on Thursday, July 16. Her hospital had never received an emergency call for a transplant for someone in another country, but Jessa was a child and an American citizen. They had to try to help her, Dr. Ventura said.

She alerted the rest of the transplant team, including someone who would contact insurers to make sure the bills would be paid. Doctors on the team began putting out notices that they would soon need a liver for a desperately ill child. They also prepared to evaluate family members to see if anyone could be a live donor, giving up part of the liver for a transplant.

The teams agreed on what had most likely shut down Jessa’s liver: Wilson’s disease, a genetic disorder that causes the body to accumulate copper, which gradually builds up to toxic levels. The tipping point often occurs when patients are in their teens or 20s. In some, like Jessa, the disease gives no warning signs before the liver suddenly stops working. Jessa’s blood tests suggested Wilson’s, and an eye exam found hints of a telltale ring of copper deposits around the iris.

The family was stunned. Wilson’s disease is rare, affecting one person in 30,000. Jessa’s parents are healthy and had no idea that they carried the disease. No one in either family had ever had it, as far as they knew. The gene is recessive, so people who carry one copy do not develop symptoms. But Jessa inherited two copies, one from each parent. The double dose gave her the disease. Her older sister, tested after Jessa became ill, does not have the disease. The real challenge would be to stabilize Jessa long enough to survive the trans-Atlantic flight. Dr. Steven J. Lobritto, NewYork-Presbyterian’s medical director for pediatric liver transplants, urged Dr. Lalazar and his colleagues to perform plasmapheresis, a procedure that separates blood cells from plasma and lets doctors replace the patient’s plasma. In Wilson’s, removing the plasma can lower the copper level and reverse some of its toxic effects.