Association of a nonsynonymous variant of DAOA with visuospatial ability in a bipolar family sample.
BACKGROUND
Bipolar disorder and schizophrenia are hypothesized to share some genetic background.


METHODS
In a two-phase study, we evaluated the effect of five promising candidate genes for psychotic disorders, DAOA, COMT, DTNBP1, NRG1, and AKT1, on bipolar spectrum disorder, psychotic disorder, and related cognitive endophenotypes in a Finnish family-based sample ascertained for bipolar disorder.


RESULTS
In initial screening of 362 individuals from 63 families, we found only marginal evidence for association with the diagnosis-based dichotomous classification. Those associations did not strengthen when we genotyped the complete sample of 723 individuals from 180 families. We observed a significant association of DAOA variants rs3916966 and rs2391191 with visuospatial ability (Quantitative Transmission Disequilibrium Test [QTDT]; p = 4 x 10(-6) and 5 x 10(-6), respectively) (n = 159) with the two variants in almost complete linkage disequilibrium. The COMT variant rs165599 also associated with visuospatial ability, and in our dataset, we saw an additive effect of DAOA and COMT variants on this neuropsychological trait.


CONCLUSIONS
The ancestral allele (Arg) of the nonsynonymous common DAOA variant rs2391191 (Arg30Lys) was found to predispose to impaired performance. The DAOA gene may play a role in predisposing individuals to a mixed phenotype of psychosis and mania and to impairments in related neuropsychological traits.
Soronen
Pia
P
Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland.
Silander
Kaisa
K
Antila
Mervi
M
Palo
Outi M
OM
Tuulio-Henriksson
Annamari
A
Kieseppä
Tuula
T
Ellonen
Pekka
P
Wedenoja
Juho
J
Turunen
Joni A
JA
Pietiläinen
Olli P H
OP
Hennah
William
W
Lönnqvist
Jouko
J
Peltonen
Leena
L
Partonen
Timo
T
Paunio
Tiina
T
D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000235:genetics* / Q000503:physiopathology*; D002352:Carrier Proteins / Q000235:genetics*; D002394:Catechol O-Methyltransferase / Q000235:genetics; D005192:Family Health; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D015810:Linkage Disequilibrium; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D020641:Polymorphism, Single Nucleotide; D013028:Space Perception / Q000502:physiology*
D002352:Carrier Proteins; C475071:DAOA protein, human; D047908:Intracellular Signaling Peptides and Proteins; D002394:Catechol O-Methyltransferase