title: Schizophrenia spectrum disorders and eye tracking dysfunction in singleton and multiplex schizophrenia families.
abstract: One line of research which is helping to unravel the genetic susceptibility to schizophrenia (SZ) is the analysis of eye tracking dysfunction (ETD), a quantifiable phenotypic marker. To investigate if such a biological marker is also present in singleton schizophrenia families, we examined eye tracking in members of singleton families (N=53) and compared it to members of multiplex (N=76) and nonpsychiatric families (N=71) using high resolution infrared oculography. The prevalence of ETD defined by gain values (eye/target velocity) and saccadic frequencies during smooth pursuit at 15 degrees /s did not differ between multiplex and singleton families in either the schizophrenic index patients or their relatives, but was significantly different from nonpsychotic families. ETD rate was higher in those relatives with compared to those without a diagnosis of a schizophrenia spectrum disorder. In relatives with a spectrum disorder, ETD appeared to be associated with traits for "sensitivity" and "suspiciousness". In the group of relatives from singleton families without a schizophrenia spectrum disorder, we still found a higher prevalence of ETD than in nonpsychotic families. Our results suggest that eye tracking dysfunction is a very sensitive biological marker for the vulnerability to schizophrenia, even in those cases where no psychopathological symptoms or signs are obvious. ETD in schizophrenia is suggested to serve as a neurophysiological type model, indicating a perception deficit.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Lübeck School of Medicine, Germany. lencer.r@psychiatry.mu.luebeck.de
authors.forename: Rebekka
authors.initials: R
authors.lastname: Lencer
authors.forename: Katja
authors.initials: K
authors.lastname: Trillenberg-Krecker
authors.forename: Eberhard
authors.initials: E
authors.lastname: Schwinger
authors.forename: Volker
authors.initials: V
authors.lastname: Arolt
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers; D004585:Electrooculography; D005191:Family Characteristics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015835:Ocular Motility Disorders / Q000209:etiology*; D010375:Pedigree; D010641:Phenotype; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000209:etiology; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology
chemical_list: D015415:Biomarkers