Genetic Link to Schizophrenia Found in Fetal Brain Development, Researchers Confirm

From birth to age three, a child’s brain develops at a faster rate than it will for the rest of their life. As scientists continue researching possible treatments for mental illnesses, they have taken into account these crucial years — and even prior.

Schizophrenia, a severe mental disorder, affects 50 million people worldwide and has no cure. This condition makes it difficult for an individual to interpret reality. Abnormal social behavior is one of the most common early signs of schizophrenia, but can be easily mistaken for an autism spectrum disorder or other condition, especially in the formative years.

In most cases, schizophrenia is often left undiagnosed until adolescence or adulthood. As it’s considered an adult-onset mental illness, doctors rarely consider diagnosing children, despite the condition running in families.

Using technology to identify specific chromosomes, scientists have officially confirmed the underlying genetics of this mental disorder, which they long thought were true. Researchers have now proven that the genetic disruptions that lead to schizophrenia occur during crucial brain development.

Hyejung Won, a UCLA postdoctoral fellow and first author of the newest study, says that a 2014 study that proved the existence of a genetic relation to schizophrenia was very important precursor to the new findings. There are 108 locations related to schizophrenia on the human genome.

However, those findings still required more attention, as the researchers did not find these locations among the region of the genome that they expected. To study this further, Dr. Daniel Geschwind, principal investigator and a professor of neurology and psychiatry at the University of California, and his team chemically mapped these locations of the brain cells. Since schizophrenia is believed to be caused by an abnormal development of the cerebral cortex, they looked at those specific cells.

The team found that the majority of the schizophrenia-linked DNA came into direct contact with important genes that are necessary for brain development. Therefore, genes that increase risk of schizophrenia are most active during early brain development — in the fetal stage prior to 24 weeks gestation.

“People really didn’t think that it may have any fetal components,” said Won. “Maybe fetal brain developmental period is a very critical for the onset of this disorder, even though the onset — really showing off the symptoms — comes at a much later time.”

The research team stresses that there is no singular gene that causes schizophrenia. Having one locus (location) associated with schizophrenia does not mean that you are schizophrenic. Multiple loci in conjunction with one another increase the possibility of schizophrenia.

Dr. Geschwind hopes that by using a similar method, researchers could identify the genes that lead to autism spectrum disorders as well as other conditions of the brain.