No evidence for phenotypic variation between probands in case-control versus family-based association studies of schizophrenia.
Traditional case-control genetic association studies utilizing unrelated probands are often used interchangeably with family-based designs to detect genes for complex psychiatric disorders. This strategy may be limited, however, if significant phenotypic variation exists between probands enrolled in these two types of studies. The present study compared 37 probands enrolled in a case-control study of schizophrenia with 37 age-, sex-, and ethnically matched probands enrolled in a family-based study of schizophrenia. Age of onset of illness was compared as well as performance on a battery of cognitive tests assessing attention, working memory, executive function, and verbal memory. Results revealed no significant differences in age of onset between the two groups or on any measure of cognitive performance. These data do not support reports of significant phenotypic variation between probands in case-control and family-based studies, and suggest that studies utilizing family-based approaches may be used to replicate reports of association made with case-control designs in schizophrenia.
Malhotra
Anil K
AK
Hillside Hospital, Psychiatry Research, Glen Oaks, New York 11004, USA. malhotra@lij.edu
Bates
John A
JA
Jaeger
Judith
J
Petrides
Georgios
G
Robinson
Delbert G
DG
Bilder
Robert M
RM
Nassauer
Katharine W
KW
D000328:Adult; D017668:Age of Onset; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology; D003627:Data Interpretation, Statistical; D005192:Family Health; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007360:Intelligence; D008297:Male; D010641:Phenotype; D011932:Reading; D012559:Schizophrenia / Q000235:genetics* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D014936:Word Association Tests