title: Admixture analysis of smooth pursuit eye movements in probands with schizophrenia and their relatives suggests gain and leading saccades are potential endophenotypes.
abstract: Abnormalities during a smooth pursuit eye movement task (SPEM) are common in schizophrenic patients and their relatives. This study assessed various components of SPEM performance in first-degree unaffected relatives of schizophrenic patients. One hundred individuals with schizophrenia, 137 unaffected first-degree relatives, and 69 normal controls completed a 16.7 degrees/s SPEM task. Smooth pursuit gain, catch-up saccades (CUS), large anticipatory saccades, and leading saccades (LS) were identified. Groups were compared with parametric and admixture analyses. Schizophrenic patients performed more poorly than unaffected relatives and normals on gain, CUS, and LS. Unaffected relatives were more frequently impaired than normals only on gain and LS. Relatives of childhood-onset and adult-onset probands had similar impairments. Gain and frequency of leading saccades may be genetic endophenotypes in childhood-onset and adult-onset schizophrenia.
authors.affiliation: Department of Psychiatry, Denver Veterans' Administration Medical Center, Colorado, USA. randy.ross@uchsc.edu
authors.forename: Randal G
authors.initials: RG
authors.lastname: Ross
authors.forename: Ann
authors.initials: A
authors.lastname: Olincy
authors.forename: Susan K
authors.initials: SK
authors.lastname: Mikulich
authors.forename: Allen D
authors.initials: AD
authors.lastname: Radant
authors.forename: Josette G
authors.initials: JG
authors.lastname: Harris
authors.forename: Merilyne
authors.initials: M
authors.lastname: Waldo
authors.forename: Nina
authors.initials: N
authors.lastname: Compagnon
authors.forename: Shari
authors.initials: S
authors.lastname: Heinlein
authors.forename: Sherry
authors.initials: S
authors.lastname: Leonard
authors.forename: Gary O
authors.initials: GO
authors.lastname: Zerbe
authors.forename: Lawrence
authors.initials: L
authors.lastname: Adler
authors.forename: Robert
authors.initials: R
authors.lastname: Freedman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011618:Psychotic Disorders / Q000175:diagnosis / Q000235:genetics*; D011698:Pursuit, Smooth / Q000235:genetics*; D012016:Reference Values; D012306:Risk; D012438:Saccades / Q000235:genetics*; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*