Among identical twins of a schizophrenia victim, what proportion do not develop schizophrenia?

In understanding the genetic influences on schizophrenia, studies have shown that identical twins (monozygotic twins) share nearly 100% of their genetic material. However, the concordance rate for schizophrenia in identical twins is not 100%. This means that if one twin has schizophrenia, the other twin does not necessarily also have it, reflecting the impact of environmental factors in addition to genetic predispositions.

Research indicates that the concordance rate for schizophrenia among identical twins is approximately 50%. Therefore, if one twin has the disorder, there's about a 50% chance that the other twin will not develop schizophrenia. This highlights the complex interplay of genetics and environmental influences in the development of the disorder. As a result, the proportion of identical twins whose schizophrenia-affected sibling does not develop the disorder aligns with the understanding of about one-half, confirming the accuracy of the selected answer.