Are eye movement abnormalities indicators of genetic vulnerability to schizophrenia?
Fifty to eighty-five percent of schizophrenic patients are impaired on ocular pursuit paradigms. However, results regarding the relatives are more discordant. The aim of this study was to investigate whether eye movement disorders could be a vulnerability marker of schizophrenia.


METHODS
Twenty-one schizophrenic patients (DSM-IV), 31 first-degree relatives of those patients without schizophrenic spectrum disorders, and two groups of healthy controls matched by age and sex were included. Three oculomotor tasks (smooth pursuit, reflexive saccades and antisaccades) were used.


RESULTS
Patients had a lower averaged gain (P= 0.035) during smooth pursuit than controls, made less correct visually guided saccades (P< 0.001) and more antisaccades errors (P= 0.002) than controls. In contrast, none of the comparison between the relatives and their controls was significant.


CONCLUSIONS
Schizophrenic patients were impaired on smooth pursuit and antisaccade paradigms. None of these impairments was, however, observed in their first-degree relatives. Our results suggest that the eye movement parameters tested could not be considered as vulnerability markers for schizophrenia.
Boudet
C
C
Groupe d'imagerie neurofonctionnelle (GIN), UMR 6194, CNRS/CEA/Université de Caen/Université Paris-V, centre Cyceron, boulevard H.-Becquerel, 14000 Caen, France.
Bocca
M L
ML
Chabot
B
B
Delamillieure
P
P
Brazo
P
P
Denise
P
P
Dollfus
S
S
D000328:Adult; D004198:Disease Susceptibility; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000235:genetics*; D011698:Pursuit, Smooth / Q000235:genetics; D012018:Reflex / Q000235:genetics; D012438:Saccades / Q000235:genetics; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*
D005819:Genetic Markers