De novo mutations -- genetic errors that are present in patients but not in their parents -- are more frequent in schizophrenic patients than in normal individuals, according to an international group of scientists led by Dr. Guy A. Rouleau of the University of Montreal and CHU Sainte-Justine Hospital. The discovery, published in Nature Genetics, may enable researchers to define how the disease results from these mutations and eventually develop new treatments for it. “The occurrence of de novo mutations, as observed in this study, may in part explain the high worldwide incidence of schizophrenia,” says Dr. Rouleau,