NO EVIDENCE OF LINKAGE BETWEEN SCHIZOPHRENIA AND D2 DOPAMINE-RECEPTORGENE LOCUS IN ITALIAN PEDIGREES

Our purpose was to test the dopamine D2 receptor gene (DRD2), the tyro sine hydroxylase (TH) gene and the monoamino oxydase A (MAO-A) gene fo r linkage to schizophrenia and bipolar disorders. We have analyzed sev en Italian families with schizophrenia and four families with bipolar disorders for a total of 68 individuals; 32 individuals were affected. Diagnoses were made using the structured clinical interview Schedule for Affective Disorders and Schizophrenia, Lifetime version (SADS-L). The results of our study provide no evidence of linkage between allele s at D2 dopamine receptor loci and schizophrenia or bipolar disorders. The markers TH gene and MAO-A gene give slightly positive or negative results suggesting the utility of further analysis on more informativ e families.