Results appearing in Nature are from a large-scale, genome-wide survey.

People with schizophrenia have an increased number of rare chromosomal changes, according to an international group of researchers. In particular, they found structural changes that have the potential to alter the function of the genes.


“The results strongly support the notion that schizophrenia may be partly caused by the effects of such structural changes in genes, both across the whole genome and in specific chromosomes,” according to Christina Hultman, associate professor at Karolinska Institute.


Copy number variants have been identified in individual schizophrenia patients and also in neurodevelopmental disorders, but large-scale, genome-wide surveys have not been performed, according to the scientists.


Thus, they decided to conduct a genome-wide survey of rare CNVs. The study comprised 3,391 patients with schizophrenia and 3,181 ancestrally matched controls.


For CNVs that were observed in less than 1% of the sample and were more than 100 kilobases in length, the total burden is increased 1.15-fold in patients with schizophrenia in comparison with controls. This effect was more pronounced for rarer, single-occurrence CNVs and for those that involved genes as opposed to those that did not.


As expected, deletions were found within the region critical for velo-cardio-facial syndrome, which includes psychotic symptoms in 30% of patients. Associations with schizophrenia were also found for large deletions on chromosome 15q13.3 and 1q21.1.


The findings appear in the advance online July 30 issue of Nature.