has been known by scientists and doctors that schizophrenia runs in families. The genetic view has been supported by studies of 1) relatives of people with schizophrenia who are adopted, 2) twins with this disorder, 3) people with schizophrenia that are adopted, and 4) chromosomal mapping. It appears likely that multiple genes are involved in creating a predisposition to develop the disorder. Studies of relatives show that scientists found repeatedly that schizophrenia is more common amount relative of people with the disorder. The more closely related that relatives are to the person with schizophrenia, the greater the likelihood of developing the disorder. Twin studies show that twins that are among the closet of relatives have received particular study by schizophrenia researchers. If genetic factors are t work schizophrenia, identical twins (who share identical genes) should have higher concordance rate for this disorder than fraternal twins should. If one fraternal twin has schizophrenia in contrast, the other twin has approximately a seventeen percent (17 %) chance of developing the disorder. Page 4Adoption studies look at adults who were adopted as infants and compare them with both their biological and their adoptive relatives. Because they were reared apart from their biological relatives, similar schizophrenia symptoms in those relatives would indicate genetic influences. Clearly the biological relatives of adoptees with schizophrenia were most likely to develop the disorder. More recent adoptions studies in other countries have convinced many researchers that the genetic factors of schizophrenia is at least as important as that found in other illnesses with a clear genetic component, such as diabetes, hypertension, and coronary artery disease. Researchers have conducted chromosomal mapping research to identify more precisely the possible genetic factors in schizophrenia. Although chromosomal research is promisin...
