Analysis of dopamine D4 receptor gene polymorphism using microchip electrophoresis

A microfabricated electrophoresis device was used for rapid polymerase chai n reaction product analysis in genotyping the dopamine D4 receptor gene (DR D4) 48 base pairs repeat polymorphism. An allelic ladder, prepared from hom ozygous individuals, was used as internal standard during the microchip ele ctrophoresis based analysis. Comparison of this novel separation method wit h the conventional slab gel and previously reported ultra-thin-layer techni ques confirmed the reliability of this new method. Genotyping of 332 health y Hungarian individuals gave the following allele frequencies: two-repeat: 0.089; three-repeat: 0.026; four-repeat: 0.674; five-repeat: 0.011; six-rep eat: 0.002; seven-repeat: 0.189; eight-repeat: 0.011. The genotype frequenc ies obtained showed no deviation from the Hardy-Weinberg equilibrium (p >0. 903), further underlying the reliability of this new genotyping technique. (C) 2001 Elsevier Science B.V. All rights reserved.