Genetic variation in the G72 (DAOA) gene affects temporal lobe and amygdala structure in subjects affected by bipolar disorder.
BACKGROUND
Variation in the G72 (DAOA) gene is understood to convey susceptibility for bipolar disorder through an uncertain mechanism. Little is known about the structural brain phenotypes associated with this gene. We hypothesised that reductions in temporal lobe and amygdala gray matter would be associated with variation at two loci in the gene for which evidence of genetic linkage has been repeatedly demonstrated.


METHODS
We examined the temporal lobe and amygdala gray matter associations of the risk variants M23 and M24 at the 5' end of the gene encoding G72 in 81 controls and 38 people with bipolar disorder.


RESULTS
Genetic variation at both the M23 and M24 loci in G72 were associated with decreased gray matter density within the left temporal pole in people with bipolar disorder. M23 was also associated with reductions in right amygdala gray matter density. The genetic imaging associations were found only in patients with bipolar disorder.


CONCLUSIONS
Genetic variation at single nucleotide polymorphisms in the G72 gene previously associated with bipolar disorder is related to reductions in temporal pole and amygdala gray matter structure in people with bipolar disorder.
Zuliani
Riccardo
R
Clinica di Psichiatria, Psicologia Medica e Psicosomatica, DPMSC, University of Udine, Udine, Italy.
Moorhead
T William J
TW
Job
Dominic
D
McKirdy
James
J
Sussmann
Jessika E D
JE
Johnstone
Eve C
EC
Lawrie
Stephen M
SM
Brambilla
Paolo
P
Hall
Jeremy
J
McIntosh
Andrew M
AM
D000328:Adult; D000679:Amygdala / Q000473:pathology*; D001714:Bipolar Disorder / Q000235:genetics* / Q000473:pathology*; D002352:Carrier Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D013702:Temporal Lobe / Q000473:pathology*
D002352:Carrier Proteins; C475071:DAOA protein, human; D047908:Intracellular Signaling Peptides and Proteins