Hungarian patient sample: likelihood ratio χ2 = 9.81, df = 3, p = 0.02. In addition, the exact chromosomal localization of the two DRD4 SNPs could be determined by direct haplotyping methods [46]. Genetic association analyses were conducted using the number of the -616C ~ -521T (C ~ T) haplotype. In the US young adult sample the frequency of the DRD4 -616C ~ -521T haplotype was increased among those who had 2 or more borderline symptoms (55% had one C ~ T and 25% had two C ~ T haplotype vs 47.4% and 5.1%, respectively, χ2 = 9.89, df = 2, p = 0.007). In the logistic regression analyses, with gender and severity of abuse accounted for in the model, the genetic effect was still significant: OR = 4.76 (1.77 - 12.79), p = 0.002. In the Hungarian patient sample univariate ANOVA showed a similar effect: those who had -616C ~ -521T haplotype on one or two chromosomes displayed a higher number of borderline symptoms (for three groups: p = 0.03, for two groups: p = 0.009, Table 3).
