An international team of researchers has found that a combination of a particular virus in the mother and a specific gene variant in the child increases the risk of the child developing schizophrenia.
The research team, led by scientists from Aarhus University in Denmark, scanned the entire genome of hundreds of people to see if there is an interaction between genes and a common virus — cytomegalovirus. They then found that the interaction ups the risk of developing schizophrenia.
According to the researchers, women who have been infected by the virus — and around 70 percent have — have a statistically significant increased risk of giving birth to a child who develops schizophrenia if the child also has the gene variant.
The risk is five times higher than usual, according to the researchers, who reported on their results in the journal, Molecular Psychiatry.
People infected with cytomegalovirus usually don’t know it, according to the researchers. They explain that the infection resulting from the virus, which belongs to the herpes virus family, is usually very mild.
The researchers also stress there is no cause for alarm. That’s because even if both risk factors are present in mother and child, there may be a variety of other factors that prevent the disease from developing in the child.
But as schizophrenia affects one percent of the population, this new knowledge could be very important, the researchers note.
“In the longer term, the development of an effective vaccine against cytomegalovirus may help to prevent many cases of schizophrenia,” said Dr. Anders Børglum, professor of medical genetics at Aarhus University.
“And our discovery emphasizes that mental disorders such as schizophrenia may arise in the context of an interaction between genes and biological environmental factors very early in life.”