A new study has come up empty-handed after pursuing a genetic explanation for why one identical twin developed multiple sclerosis while the other stayed healthy.
Researchers transcribed the complete genetic blueprints for a pair of identical twins, looking for differences that might explain why one has multiple sclerosis and the other does not. No trace of what caused the discrepancy appeared in the twins’ DNA. And scientists found no smoking gun when they compared levels of gene activity between the sick and well twin. The results appear in a report published April 29 in Nature.
“We looked under a lot of rocks and we found no differences that we could replicate,” says Stephen Kingsmore, a geneticist at the National Center for Genome Resources in Santa Fe, N.M., and leader of the new study. The finding “points to some novel environmental trigger that must be very important to the disease. We don’t know what it is.”
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