Dopamine transporter gene (DAT1) VNTR polymorphism in major psychiatric disorders: family-based association study in the Bulgarian population.
OBJECTIVE
A 40-bp variable number tandem repeat in the 3'-UTR of dopamine transporter gene (DAT1) has been examined for association with major psychiatric disorders in several case-control studies. No significant results have been found. We used a new collection of parent-offspring trios to test for association with schizophrenia (SZ), bipolar 1 disorder (BPI) and schizoaffective (SA) disorder.


METHODS
We genotyped trios from Bulgarian origin where the proband had SZ (178 trios), BPI (77 trios) and SA (29 trios). Alleles ranging from 5 to 11 repeats were observed. The results were analysed with the extended TDT (ETDT).


RESULTS
No preferential transmission of alleles was observed for any diagnostic group. The presence of allele DAT*10 was associated with the severity and frequency of auditory hallucinations, however, this result is not significant if corrected for multiple testing.


CONCLUSIONS
Our results are in agreement with previous reports of a lack of association between this polymorphism and major psychiatric disorders.
Georgieva
L
L
Department of Medical Genetics, Medical University Sofia, 2 Zdrave Street, 1431 Sofia, Bulgaria.
Dimitrova
A
A
Nikolov
I
I
Koleva
S
S
Tsvetkova
R
R
Owen
M J
MJ
Toncheva
D
D
Kirov
G
G
D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000235:genetics; D002031:Bulgaria / Q000453:epidemiology; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000235:genetics*; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics*; D009419:Nerve Tissue Proteins; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011618:Psychotic Disorders / Q000235:genetics* / Q000378:metabolism; D012559:Schizophrenia / Q000235:genetics
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human