Roughly 35 percent of people with abnormal brain subplates will eventually have schizophrenia. Schizophrenia is determined by genetic factors. Some people developed schizophrenia because of damage to the brain subplate after the second fetal trimester. There may be a cause of schizophrenia that predates birth.
Researchers compared the brains of recently deceased people who had schizophrenia with those of recently deceased people who did not have schizophrenia. They found that 35 percent of the former and none of the latter showed evidence of damage to a structure of nerve cells called the subplate. They knew that this damage must have occurred prior to the second fetal trimester, when the subplate controls the development of the connections between the different parts of the brain.
Which one of the following conclusions is most strongly supported by the information above?