What Blood, Spit and a Data Bank Can Tell Us About Disease
Willie Mae Washington, 92, and her daughter Ida are among the 15,000 women in the Oakland area participating in a study on genetic links to diseases like cancer. Photo by Robert Durell.
A giant data bank containing genetic information on 200,000 people is in full operation in the San Francisco Bay Area. It's being ballyhooed by its founders as the world's best such repository -- more racially diverse than others in England and Iceland -- and linked to the electronic medical records of the participants. Researchers have begun to use it to explore the links between genes and disease, and, to some extent, between environmental factors like pesticides and genetics. The big data bank is a cooperative venture between the University of California at San Francisco and Kaiser Permanente, the big health provider that keeps health records for its 5.5 million California members. It is part of the genetic revolution that appears to be reshaping medical research.
There's another data bank nearby that isn't as big, but may be of major value as well. It contains more than 100,000 vials of blood drawn from 15,000 women, plus their health records, starting in 1959. That makes it more than half a century old. Many of those samples are from the daughters and the granddaughters (and even a few great-granddaughters) of the original subjects, who, as with the larger data bank, were all members of Kaiser. The people who contributed to this bank are also racially diverse. Currently the bank is collecting new samples, using improved techniques.
According to epidemiologist Barbara Cohn, who directs the Child Health and Development Studies in Berkeley, Calif., the generational data going back 55 years is unique and extremely important in figuring out how diseases like breast cancer appear in families. One in eight women is diagnosed with breast cancer during their lifetimes, according to the American Cancer Society, and 70 to 75 percent of those cancers go unexplained. The women have no known risk factors. Doing research on human subjects is always tricky and difficult, Cohn says, and the material collected over such a long time can provide clues that newer studies or data may not. Timing is crucial to discovering exposure to chemicals like DDT or other carcinogens. For example, blood collected during pregnancy, years ago, may provide information that could impact children and their children. Studies using those samples can look to the origins of breast cancer that may begin before birth. A fetus can be exposed to a disease that can be seen two generations hence.
The older vials of blood are actually stored in Frederick, Va. Cohn believes the data bank (financially administered by the Public Health Institute of Berkeley) may be able to link environmental pollutants to disease more efficiently than the larger Kaiser-UCSF bank, because it goes back much farther and the samples can be tested for specific environmental exposures.
Forty years ago, Ida Washington's mother, Willie Mae Washington, was diagnosed with breast cancer. The mother -- who is now 92, with her cancer in remission -- took part in the beginning of the Child Health and Development Studies, and more recently Ida Washington, who is 52, has been taking part as well. They are eager to find out why Willie Mae developed the disease, since she didn't seem to exhibit any of the risk factors. Cohn calls the women "a national treasure", and is convinced their records and their blood can contribute to the understanding of the disease and the environmental factors that may encourage it.
The study expects to publish shortly new findings on how exposure to DDT (which is now banned) during a mother's pregnancy could affect a daughter's ability to get pregnant, and increase a son's risk of testicular cancer. Those are the kinds of questions the study is designed to explore.
So while this data bank may not rival the big UCSF-Kaiser project in scope and depth, it plays a key role in the a long, complicated war to understand the connections between environment, genetics and disease.
Watch PBS NewsHour Tuesday for more on genetic data banks.