FAMILIAL TRANSMISSION OF 2 INDEPENDENT SACCADIC ABNORMALITIES IN SCHIZOPHRENIA

Difficulties with inhibiting inappropriate responses, i.e. disinhibiti on. and problems with spatial memory are both presumed to be a part of the phenotypic expression of the generic risk for schizophrenia. Schi zophrenic probands are impaired on saccadic eye movement tasks which r equire (a) response inhibition to prepotent stimuli and (b) generation of an accurate response to a remembered or calculated spatial locatio n, but it is unknown how these deficits are inherited. Sixteen schizop hrenic probands, their 32 parents, and two normal control groups compl eted a delayed oculomotor response and an antisaccade task. The parent s with a positive ancestral family history for chronic psychosis (n=8) were presumed to be more likely than their family history-negative sp ouses to be genetic carriers for schizophrenia. Probands and their pos itive family history parents had more failures of response inhibition than did normal control groups. However, it was the probands and their negative family history spouses who demonstrated impaired accuracy of the remembered-or antisaccades. Disinhibition may be closely tied to a specific genetic risk for schizophrenia. However, a second familial factor related to the maintenance or manipulation of spatial informati on may also contribute to the genetic risk of the full clinical disord er. (C) 1998 Elsevier Science B.V.