DOPAMINE-D(4) RECEPTOR VARIANTS IN UNRELATED SCHIZOPHRENIC CASES AND CONTROLS

The D4 dopamine receptor (D4DR) exists in multiple allelic forms (Van Tol et al.: Nature 358:149-152, 1992) which involve different numbers of a 48 basepair repeat sequence in the putative third cytoplasmic loo p. Different binding properties have been reported for at least three of the alleles in cDNA binding assays with clozapine, an atypical neur oleptic, and spiperone (Van Tol et al., 1992). We have examined 115 un related schizophrenic cases defined by DSM-III-R criteria and 115 cont rols of similar ethnicity to determine the frequency of seven differen t D4 alleles in these groups. No statistically significant difference in the distribution of the alleles existed between cases and controls, although a trend towards a greater prevalence of homozygotes for the 4-repeat allele was observed in schizophrenics. (C) 1993 Wiley-Liss, I nc.