More 60-Second Science Crohn’s disease is a real pain in the
gut. This inflammatory disorder can lead to some serious
intestinal difficulties. And heredity is partly to blame: some
30 different genes enhance susceptibility. But not everyone who
has the genes gets Crohn’s. Now scientists find that those with
one type of risky gene may also need to catch a virus to trigger
the disease. The results appear in the journal Cell. [Ken
Cadwell et al., citation to come.] Doctors have long suspected
that some sort of virus might precipitate autoimmune disorders,
like lupus or multiple sclerosis. But in the case of Crohn’s,
researchers stumbled across the connection by accident. They
were studying mice that carry a version of a gene associated
with Crohn’s. These animals develop gut problems similar to
those seen in humans. Then the researchers started keeping the
animals in clean cages. Really clean cages, in which the
bedding, food, and water are sterilized. And the squeaky clean
mice, even with the risky gene, stayed