by observing this early development using human pluripotent stem cells, the team was able to identify several sets of genes that are switched on during the early stages of life — either in vitro or in the fetal brain — with each set playing a distinct functional role. they discovered that the genetic risk factors associated with schizophrenia and other psychiatric disorders were highly concentrated in these gene sets.
“in vitro experiments showed that when activation of these sets is disrupted, the shape, movement and electrical activity of developing brain cells is altered, linking changes in these properties to disease,” shin said.
these changes are associated with the early onset of certain psychiatric disorders — such as developmental delay, autism and adhd — but also, unexpectedly, other conditions that typically present later, such as bipolar disorder and major depression. because some of these genes are switched on long before birth, the finding raises the possibility that they can be therapeutically targeted later in life.
“previous studies have shown that genes active in mature brain cells are enriched for common genetic variants contributing to schizophrenia,” pocklington said. “much of this enrichment was captured by the early developmental gene sets, which seem to contain a greater burden of common genetic risk factors.