Increased hippocampal volume in schizophrenics' parents with ancestral history of schizophrenia.
OBJECTIVE
Decreased hippocampal volume is one of the hypothesized pathological features of schizophrenia, but it is not known if this abnormality is familially transmitted. The aim of this study was to measure the hippocampal volume of the parents of schizophrenic probands, in relationship to the apparent transmission of genetic risk.


METHODS
Eighteen subjects from families consisting of a schizophrenic proband and two clinically unaffected parents were studied. Probands were compared to six control subjects, matched for age, sex, and educational level. The six families were selected so that only one parent had an ancestral family history of schizophrenia. The volumes of both hippocampi were measured by magnetic resonance imaging and adjusted for age and whole brain volume.


RESULTS
The total hippocampal volumes of the parents with ancestral family history of schizophrenia were significantly larger than those of their schizophrenic offspring.


CONCLUSIONS
This study suggests that decreased hippocampal volume in schizophrenia is not a familially transmitted abnormality. Rather, it appears that clinically unaffected parents who transmit apparent genetic risk for schizophrenia may have increased hippocampal volume, which may be a protective factor against the illness.
Harris
Josette G
JG
Department of Psychiatry, University of Colorado School of Medicine, 4200 E. 9th Avenue, Denver, CO 80262, USA.
Young
David A
DA
Rojas
Donald C
DC
Cajade-Law
Ana
A
Scherzinger
Ann
A
Nawroz
Safia
S
Adler
Lawrence E
LE
Cullum
C Munro
CM
Simon
Jack
J
Freedman
Robert
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012306:Risk; D012559:Schizophrenia / Q000235:genetics* / Q000473:pathology