Can brain damage protect against schizophrenia? A case report of twins.

In a pair of male monozygotic twins discordant for schizophrenia, MRI revealed no abnormality in the ill proband, but extensive white-matter damage of likely congenital origin in the psychiatrically normal twin. These findings are difficult to reconcile with multifactorial models of schizophrenia, and raise the possibility that some forms of brain damage may preclude expression of the schizophrenia genotype.