Admixture analysis of smooth pursuit eye movements in probands with schizophrenia and their relatives suggests gain and leading saccades are potential endophenotypes.
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.
Ross
Randal G
RG
Department of Psychiatry, Denver Veterans' Administration Medical Center, Colorado, USA. randy.ross@uchsc.edu
Olincy
Ann
A
Mikulich
Susan K
SK
Radant
Allen D
AD
Harris
Josette G
JG
Waldo
Merilyne
M
Compagnon
Nina
N
Heinlein
Shari
S
Leonard
Sherry
S
Zerbe
Gary O
GO
Adler
Lawrence
L
Freedman
Robert
R
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*