GENETIC-STUDY OF DOPAMINE D-1, D-2, AND D-4 RECEPTORS IN SCHIZOPHRENIA

The goal of this study was to define precisely the involvement of the dopamine D-1, D-2, and D-4 receptor genes in the etiology of schizophr enia. A linkage analysis using the lod score method was performed in 3 7 families originating from France (n = 14) and from the Island of La Reunion in the Indian Ocean (n = 23). No evidence of linkage between s chizophrenia and genetic markers located at these loci was found. A si mulation study was carried out to gauge the significance of these resu lts. The conclusions of a nonparametric linkage test (i.e., the affect ed pedigree member method) were equally negative. For each genetic mar ker, an allelic association with the disease was also sought: 80 unrel ated patients and 80 healthy control subjects were tested, and no sign ificant association was found. These results, which are in agreement w ith those obtained by other groups, do not support the involvement of the dopamine D-1, D-2, and D-4 receptor genes in the pathogenesis of s chizophrenia.