Eye movements of teenage children of schizophrenics: a possible inherited marker of susceptibility to the disease.

Teenage children each having one schizophrenic parent showed deficits in oculomotor control which are also found in schizophrenic subjects compared with controls. They made significantly more saccadic eye movements interrupting smooth pursuit ocular tracking. They also made significantly more double-jump saccadic movements in a looking task. Since this latter difference was true only when the visual target was illuminated during the saccade (p less than 0.001), the cause was likely visual processing and not a fixation stability problem. The two measures correlated significantly for all subjects (r = 0.63), and half the experimentals had scores more than two standard deviations above the mean for controls. This suggests that a pattern of oculomotor dysfunction found in schizophrenics which comes from a single source may act as a marker for susceptibility of their offspring to the disease.