A study has found evidence of a hereditary link to schizophrenia, and the discovery could help scientists find new treatments for the disorder that strikes one person in 100.

The study published Thursday found evidence that a single gene may help trigger the disease and may predispose people to a personality disorder that makes them loners or to other mental conditions thought unrelated to schizophrenia.Two other studies, however, found no evidence of the gene.

The researchers studied 104 members of seven families from Iceland and Great Britain that had displayed multiple cases of schizophrenia in at least three generations.

The study included 39 schizophrenics, five people with "schizoid personality disorder" and 10 people with conditions such as depression that are not thought related to schizophrenia. It found that family members who apparently inherited the gene may have acquired an 86 percent risk of developing schizophrenia or one of the other disorders.

The work was done by Hugh Gurling of the University of London with colleagues there, at the University of Southampton in England, at the California College of Medicine in Irvine, and in Reykjavik, Iceland.