"It came out of nowhere," said Levey-Klassen, who lives in Mill Valley. "They say it's environmental, not genetic."

Unable to get Levey's leukemia under control, Beth Israel transferred her to Sloan-Kettering Cancer Center in New York for a course of experimental chemotherapy.

Now Levey's future depends on two things: that her leukemia go into remission and that a matching bone marrow donor be found.

She's still waiting.

"None of us are a match for my sister Jane," said Levey-Klassen, who works as Rabbi Lavey Derby's assistant at Congregation Kol Shofar in Tiburon.

The most likely place to find a match is within a patient's family, Levey-Klassen said. The next resource is the registry of the National Marrow Donor Program. "Chances are that [a matching donor] will be a member of the Jewish community because of the genetics," she said.

Levey-Klassen began researching the situation to see what she could do.

The answer came by way of a telephone message left at Kol Shofar. It was from Karen Reeves, "saying she wanted to do something for the National Bone Marrow drive," Levey-Klassen said. "She was looking for help. I knew about the [Bone Marrow Donor] bank and knew there weren't many Jews registered."

Reeves, who lives in Kentfield, was working against the clock to find a donor for her first cousin, Keren Rosenberg, who was diagnosed with leukemia about the same time as Levey. Coincidentally, Rosenberg, a 44-year-old Israeli, had also been moved to Sloan-Kettering for treatment.

Reeves and Levey-Klassen began contacting synagogues, lining up funding and checking possible dates to hold a bone marrow donor drive. When they learned a cancer workshop was schedule for Sunday at the Marin Jewish Community Center, they had their date and place.

"It's a chance to save a life," Levey-Klassen said.

The National Marrow Donor Program estimates the survival rate for patients receiving marrow transplants is 40 to 60 percent. These are patients for whom the disease would be fatal without the transplant. The average patient has an 80 percent chance of finding a matching donor in the registry.

But so far, Levey and Rosenberg haven't had any luck.

Reeves suspects this could have a lot to do with the fact that both women are children of Holocaust survivors.

"The people we came from were very likely wiped out by the Holocaust," said Reeves, herself the child of survivors. "As a result of that group being so small, the likelihood of a match is even lower than among the general population."

Their hope is that by getting more Jews into the registry, the chances of finding a match will improve.

According to Susan Flemer, bone marrow supervisor at San Francisco's Blood Centers of the Pacific, being tested involves filling out forms and having a small amount of blood drawn — about a 15-minute process. Although there is a charge for this procedure, the Northern California chapter of the Leukemia Society of America, the National Marrow Donor Program and some private donors have underwritten part of the cost for Sunday's drive.

"Money should not be an issue [in deciding whether or not to be tested]," said Reeves. "If we get so overwhelmed by bodies, we'll get the money."

The blood is later tested for three antigens, and this information, along with the person's name, is added to the registry. Currently almost 3.2 million people are registered internationally.

Those who come up as possible matches undergo further blood tests to see if all six of the necessary antigens match.

The actual procedure is done in a hospital, under general anesthesia or a spinal block. The marrow is extracted with a needle from the hip and taken to the recipient's location by personal courier.

According to Flemer, the donor usually stays overnight at the hospital for observation and will experience slight discomfort after the procedure. The marrow will replenish in four to six weeks.

"The prospect of saving a life overshadows whatever discomfort there is," said Levey-Klassen, whose name is already in the donor registry. "For me it's more of a spiritual blessing to be able to save someone's life."

She also points out that potential donors can opt out at any juncture. Putting your name in the registry is not a commitment to being a donor.

Although Levey-Klassen and Reeves are looking forward to a successful donor drive, they already have gotten some rewards.

"I've been overwhelmed with the support of the Jewish community," said Reeves. "People call back right away. That's always heartwarming."

Donations can be made to the Jewish Donor Marrow Fund, c/o Susan Flemer, Bone Marrow Supervisor, Blood Centers of the Pacific, 270 Masonic Ave., S.F., CA 94118.