Background: Association studies between marker alleles at the D-2 dopamine
receptor gene (DRD2) and various psychiatric illnesses have produced confli
cting results. Reports of allelic associations were originally made with al
coholism, bur were then extended to other psychiatric disorders, including
posttraumatic stress disorder (PTSD).
Methods: We studied allele frequency of the DRD2 TaqI "A," "B," and "D" sys
tem markers in 52 European-American subjects with diagnoses of PTSD (based
on structured interviews).
Results: Frequency of the AI allele in this sample was .15, not significant
ly different from the .19 allele frequency seen in 87 control subjects. We
were thus unable to replicate the previous reports of allelic association b
etween the DRD2 TaqI "A1" allele and PTSD. There were also no significant d
ifferences in allele frequency for the "B" or "D" systems. We then computed
three marker (TaqI "A," "B," and "D" system) haplotypes for the sample; DR
D2 haplotype frequencies also did not differ between control subjects and s
ubjects with PTSD,
Conclusions: We conclude that DRD2 alleles are not associated with PTSD in
this sample, and that genetic variation at the DRD2 locus is not likely to
be an important contributor to risk for this disorder, Biol Psychiatry 1999
;45:620-625 (C) 1999 Society of Biological Psychiatry.