"My name is David and I have a Jewish disease," David Rancer told his teacher Barry Savin on his first day of fifth grade last year. It's a story that says a lot about David Rancer, a straightforward, out-there, aware kid with a very serious disease. It's a funny story with a sad ending.

On May 1, 11-year-old David Rancer died of his Jewish disease at Children's Hospital Oakland.

The disease is familial dysautonomia or FD, a genetic disorder that affects the autonomic and sensory nervous systems and occurs almost exclusively among people of Eastern European (Ashkenazi) Jewish descent.

The disease has a wide variety of symptoms, including the inability to digest food, out-of-control body temperatures and blood pressure, scoliosis of the spine and decreased or no sensitivity to pain, according to Michael Rancer, David's father.

Although the disease is present at birth, the myriad symptoms makes the diagnosis difficult. According to Rancer one hallmark that should raise a red flag for doctors is the inability to produce overflow tears.

"It's the one symptom which is unique, the lack of tears in the eyes," said Rancer, who lives in Piedmont with his wife, Susan, and their 15-year-old daughter, Emily, who does not have the disease. He remembers David crying hysterically without any tears coming down his cheeks.

In January, researchers at Massachusetts General Hospital isolated the FD gene, a discovery that opens the door to many diagnostic and treatment possibilities.

Although it probably won't happen for five or 10 years, Kaiser geneticist Dr. Ronald Bachman expects that stem-cell therapy will result. Eventually, treatment could be given in utero.

While that may be years ahead, genetic screening became available last month, enabling Ashkenazi Jews to find out if they are carriers.

The FD gene is recessive, explained geneticist Susan Slaugenhaupt from her Boston office. Slaugenhaupt is on the research team that isolated the gene. Because the gene is recessive, both partners must be carriers for the disease to manifest itself in their child and they have a one in four chance of having an affected child.

Now that screening is available, once these couples have been identified and achieve a pregnancy, the fetus can be tested to determine if the gene is present. Slaugenhaupt said that during the course of their research, there were 69 births to parents who were both carriers and not a single baby was affected with the disease. "The test was never wrong," Slaugenhaupt said.

Today there are only 350 known FD cases worldwide. Since David's death, there have been no known cases in Northern California.

Even Bachman, with 33 years of practice behind him, has never treated a patient with FD.

"The carrier frequency [for FD] is as high as it is for Tay-Sachs," said Slaugenhaupt. However, because of widespread publicity, many Ashkenazi Jews are getting screened for Tay-Sachs before they have children. Tay-Sachs, with 38,000 carriers, potentially affects one in 2,500 Ashkenazi newborns, according to the National Foundation for Jewish Genetic Diseases Inc.

Logically, there should be at least as many reported FD cases as incidents of Tay-Sachs, according to Slaugenhaupt, but that's not so. She thinks it's because "FD is a more difficult disease to diagnose."

David is a case in point. He wasn't diagnosed until he was 21 months old, even though the signs were there. It wasn't until David was diagnosed with aspiration pneumonia that a doctor thought something could be seriously wrong.

Since their son's diagnosis in February 1991, the Rancers have become lay experts in the disease and put together an Internet support group with other parents of FD children. They also founded FD Hope, which funds FD research, operates an informational center for parents and serves as a network for FD families.

"David was considered one of the healthiest kids," said Rancer. Most severe cases have scoliosis, corneal scarring, retching and gagging. Some children are unable to take food by mouth and are fed entirely through a tube.

Fifty percent of people with FD die before they reach 30.

"David had high blood pressure, which is what killed him," his father said.

Earlier this year he began to deteriorate. There were lengthy hospitalizations at Children's Hospital. For his family there was no respite.

"David's parents were in a dual role. They were not only parents but 24-hour caregivers. It was imprisoning," said Rabbi Andrea Berlin of Oakland's Temple Sinai, where the family belongs. "His parents couldn't leave the house when he was home when he was in one of his crashing periods."

Sinai organized a schedule for members to go to the Rancers' home or the hospital to sit with David and relieve his parents.

Although David came home in mid-April, his parents said he never regained his energy and vigor. On April 27, David collapsed and was taken to the hospital again. His mother suspects he had had a stroke. The doctors were unable to bring his blood pressure down and David developed a brain bleed.

"Michael and Susan Rancer are amazing parents," said Berlin. "They have never expressed anger or unfairness. Never took it out on doctors or nurses and were grateful to other people."

The Rancers donated David's organs and tissues for research. Michael Rancer will stay active in FD Hope and plans to petition the American College of Obstetrics and Gynecology to adopt and promote FD genetic screening. Even in the face of their own tragedy, he knows that some people are even worse off.

"There are families that have put up with lots more than we have," Rancer said. "Families with two or three children with the disease."