It appears to concentrate in certain families, suggesting that genes are involved, and scientists are determinedly hunting those genes. But what we're finding is that the genetics in schizophrenia is very complex. Bassett's group, for instance, has found a strong link to a narrow region on chromosome one. She believes scientists will eventually isolate a susceptibility gene. The value of that, she says, will not be in predicting the disease but in tracking down its biology.
Understanding comes first.
Gottesman's testimony in the Hong Kong trial clearly demonstrated the limits of genetic prediction. For instance, he pointed out that some 89 percent all persons suffering from clinically obvious schizophrenia don't have a schizophrenic parent. For those who do, the average risk is now calculated at about 13 percent. That is average only. Gottesman emphasizes that the risk to an individual child may be much less than that, depending on factors ranging from environmental influences to severity of the parent's schizophrenia.