To the Editor.
—A good deal of attention has recently been focused on the relationship between the dopamine D2 receptor (DRD2) and alcoholism.1 Cloninger2 has shown that DRD2 may indeed be associated with, but not linked to, alcoholism. Now, Comings et al3 have extended the model of DRD2 as a modifier of severity not only of alcoholism but of other neuropsychiatric disorders as well, including attention-deficit disorder, autism, posttraumatic stress disorder, and Tourette's syndrome. As part of a linkage study of Tourette's syndrome,4 I had previously genotyped a sample of 14 families (N = 115) with the same DRD2 DNA probe (λhD2G1) as used in other studies. Herein is presented a reevaluation ofthose genotyped data in the context of the Comings et al proposal.The prevalence of the Al allele of the Taq IDRD2 restriction fragment length polymorphism, as opposed to its frequency, is taken
Devor EJ. The D2 Dopamine Receptor and Tourette's Syndrome. JAMA. 1992;267(5):651. doi:10.1001/jama.1992.03480050055011