14 DAY TRIAL // Genetic mutations occurring within the same generation are responsible for about 50 percent of all non-hereditary cases of schizophrenia. What this means is that – for half of patients developing the condition without parental influences – sporadic mutations are too blame.
De novo protein-altering mutations are genetic errors that occur within a person's lifetime, and cannot be found in their parents. Conversely, hereditary mutations are passed down from generation to generation. Schizophrenia itself can be transmitted from parents to children.
Investigators at the Columbia University Medical Center (CUMC) say that more than half of schizophrenia cases people do not acquire from parents are caused by sporadic, de novo mutations.
Details of the new investigation were published in the August 7 online issue of the top scientific journal Nature Genetics. The work was led by research scientists Maria Karayiorgou, MD, and Joseph A. Gogos, MD, PhD, e! Science News reports.
In order to conduct the research, the team had to analyze the genomes of schizophrenia patients, their families, and also a number of healthy control subjects. The group also paid attention to keeping results relevant, so they selected the European-descent Afrikaner population of South Africa for study.
The reason why this choice was made is that the group is genetically-isolated, which prevents the mixing of other genes and mutations. The new results are a continuation of a 15-year-old study that Karayiorgou conducted, which focused on the role of de novo mutations in this condition.
“Identification of these damaging de novo mutations has fundamentally transformed our understanding of the genetic basis of schizophrenia,” explains CUMC assistant professor of clinical neurobiology Bin Xu, PhD, who is also the first author of the study.
“The fact that the mutations are all from different genes is particularly fascinating. It suggests that many more mutations than we suspected may contribute to schizophrenia,” Karayiorgou goes on to say.
“This is probably because of the complexity of the neural circuits that are affected by the disease; many genes are needed for their development and function,” the expert explains.
Scientists were able to identify no less than 40 protein-altering genetic mutations in this population. The team says that each of these errors plays a role in the development of sporadic schizophrenia.
“Using innovative neuroscience methods, we hope to identify those neural circuit dysfunctions, so we can target them for drug development,” concludes CUMC associate professor of physiology and neuroscience Dr. Joseph Gogos, MD, PhD, who is also a coauthor of the new study.