Consider two pandemics: the white-nose syndrome now devastating North American bats and the Black Death that killed a third or more of Europeans in the 14th century. Lethality aside, they may not seem to have much in common. But recent studies suggest they both offer important lessons about understanding that the deadliness of disease organisms is very much a product of the circumstances in which they appear.
Two weeks ago in Nature, a multi-institutional team of U.S. Geological Survey scientists presented conclusive evidence the parasitic fungus that lends white-nose syndrome its name is indeed the cause of the mysterious bat epidemic. The illness came to light in New York in 2006, when cave explorers started finding thousands of little brown bats (and later, other species) dead together in the caves where they spent the winter months, their bodies covered with a white fungus, Geomyces destructans. It has since spread throughout the northeastern U.S., where bat populations have declined on average by 73 percent—which may make it one of the most rapid declines in wildlife populations ever observed. Worse, white-nose syndrome is still on the move, with documented cases in four Canadian provinces and states as far south and west as Tennessee, Missouri, and Oklahoma.
Gholson Lyon is on a crusade. It started last November, when he found out that a woman in a research study that he was conducting was pregnant. Lyon’s study had revealed that the woman carried a gene that causes a fatal disease. Yet he couldn’t tell the mother-to-be that she might be carrying a sick child due to the rules governing the study. The mother did give birth to a boy with the disease; he died in the same week that Lyon published his paper on the study, as I reported recently in Nature. Lyon was so disturbed by the situation that he is now trying to find a way for researchers to work within the rules so that they don’t face these same ethical dilemmas. And he is speaking and writing about the issue everywhere he can.
The issue of what to tell patients about their DNA is difficult enough for doctors who are treating patents rather than studying them. But it has become urgent for researchers as well, because genetic sequencing technologies are now cheap and fast enough that scientists are planning to sequence five thousand patients’ genomes this year, and as many as 30,000 next year. The US National Human Genome Research Institute will soon begin a program that will spend tens of millions of dollars to sequence the genomes of patients, like Lyon’s study subjects, who have rare genetic diseases. And researchers are also sequencing thousands of otherwise healthy people across the lifespan, from newborns to old folks.
Inevitably, researchers will find stuff in these thousands of genomes. Most of it will be difficult to understand. Some of it will clearly be linked to disease. Some of it will be newly linked to disease through these studies. The whole point of these studies is to link genes and disease. So it would seem like a good idea to tell the gracious volunteers who have donated their time and blood for these studies that they have certain genetic disease risks, right?