About 80 per cent of the risk for schizophrenia is known to be inherited but scientists have struggled to identify specific genes for the condition. Schizophrenia is not a single disease but a group of eight genetically distinct disorders each with its own set of symptoms scientists have found. The finding could be a first step toward improved diagnosis and treatment for the debilitating psychiatric illness said researchers at Washington University School of Medicine in St Louis. About 80 per cent of the risk for schizophrenia is known to be inherited but scientists have struggled to identify specific genes for