from the Hardy-Weinberg equilibrium were detected in either populations. We assume that the slight deviation from the equilibrium (χ2 = 4.099, df = 1, p = 0.043) in the Hungarian patient sample originates from possible association of the -616 C/G SNP with psychiatric disorder(s). In order to support this assumption, control subjects (with no psychiatric history) were recruited at the Institute of Psychology, Eotvos Lorand University (N = 178, age: 23.2 ± 5.0; 72.5% female) and genotyped for the studied dopaminergic polymorphism (see additional file 1). Our data demonstrated that the non-clinical Hungarian sample was indeed in Hardy-Weinberg equilibrium for -616 C/G SNP (χ2 = 0.104, df = 1, p = 0.747).
