No association between the dopamine D3 receptor Bal I polymorphism and schizophrenia in a family-based study of a Palestinian Arab population

Several recent meta-analyses appear to show a weak but significant effect o f both forms of the gly/ser DRD3 polymorphism in conferring risk for schizo phrenia. Since most studies have employed the artifact-prone case-control d esign, we thought it worthwhile to examine the role of this polymorphism us ing a robust family-based strategy in an ethnic group not previously system atically studied in psychiatric genetics, Palestinian Arabs. We failed to o btain any evidence in 129 Palestinian triads, using the haplotype relative risk (allele frequency: Pearson chi-square = 0.009, P > 0.1, df = 1, n = 25 8 alleles) or transmission disequilibrium test design (chi-square = 0.38, P > 0.1, n = 86 families) for association/linkage (or increased homozygosity ) of the DRD3 Bal I polymorphism to schizophrenia in our sample. (C) 2000 W iley-Liss, Inc.