Is Schizophrenia Inherited?
It has long been known that schizophrenia runs in families. People who have a close relative with schizophrenia are much more likely to develop the disorder than are people who have no relatives with the illness. For example, a monozygotic (identical) twin of a person with schizophrenia has the highest risk at 40 to 50 percent of developing the illness. The fact that identical twins do not always share schizophrenia is suggestive of environmental factors. A child whose parent has schizophrenia has about a 10 percent chance. By comparison, the risk of schizophrenia in the general population is about 1 percent.
Scientists are studying genetic factors in schizophrenia. Multiple genes have been linked to a predisposition to developing the disorder. In addition, factors such as prenatal difficulties like intrauterine starvation or viral infections, perinatal complications, and various non-specific stressors, seem to influence the development of schizophrenia. However, it is poorly understood exactly how these genes contribute to the development of the disorded, and it cannot yet be accurately predicted whether a given person will or will not develop the disorder.
Several regions of the human genome are being investigated to identify genes that may confer susceptibility for schizophrenia. Around 130 genes have been implicated, many of which are important in brain development. Identification of the specific genes involved and their contribution to the development of schizophrenia will provide important clues into what goes wrong in the brain to produce and sustain the illness and will guide the development of new and better treatments.
