Importantly, schizophrenia often runs in families, so scientists have long believed it is a genetic disorder.
A 2014 study of people with the psychiatric disorder provided real evidence of this: The researchers found 108 distinct locations on the human genome linked to schizophrenia.
“That was a very important study,” said UCLA postdoctoral fellow Hyejung Won, first author of the new study.
Even though the 2014 research revealed parts of the genome causing schizophrenia, the results were still puzzling, Won said. These genetic loci (locations) were not in coding regions of the genome, where a genetic message is translated into proteins, which actively perform the work necessary to maintain cellular life — and our own human lives.
Instead, the loci were in regulatory regions, where genes act more or less like managers by increasing or decreasing a target gene’s activities. Another problem: No nearby targets could be found.
Searching for an explanation, Geschwind and his colleagues theorized that possible target genes may appear only far away. When the ropes of DNA underwent complex twisting and looping in order to fit into a chromosome, the regulatory genes and their as-yet-unknown targets might actually be close together.