For decades, scientists have been hunting for genes that cause mental illness. The search has, so far, proved mostly futile. After an extensive search for a “schizophrenia gene,” no single gene or mutation studied so far seems to exert a big enough influence to be seen as a definitive cause.
In fact, researchers have struggled in their search for specific genes behind most brain disorders, including autism and Alzheimer’s disease. Unlike problems with some other parts of our body, the vast majority of brain disorder presentations are not linked to an identifiable gene.
One study suggested a different path. What if it wasn’t a single faulty gene—or even a series of genes—that always caused cognitive issues? What if it could be the genetic differences between cells?
The explanation seemed far-fetched when the study came out in 2001, but more researchers have begun to take it seriously, and the body of evidence for the theory is growing. Scientists already knew that the 85 billion to 100 billion neurons in your brain work to some extent in concert—but what they want to know is whether there is a risk when some of those cells might be singing a different genetic tune. Read the full story.
—Roxanne Khamsi