Research The Relationgship Between The Dopamine D5 Receptor Gene Polymorphism,and Cervical Dystonia

Objective:To study the relationship between the dopamine D5 receptor(DRD5)gene polymorphism and cervical dystonia in China in order to search the pathogenesy from molecular biology,and provide a moleculer basis for clinical diagnosis and treatment.Methods:A case-control study was conducted which included 25 patients with cervical dystonia and 25 normal controls.We can use a kit extracted genomic DNA from the white blood cells of blood samples.Bying polymerase chain reaction(PCR)amplification with TransTaqTM DNA Polymerase High Fidelity a DNA fragments of ORF of DRD5 was extracted.The positive clones were randomly selected and recombinant plasmid was purified,which was identified and sequenced.The chi-square test and logistic Regression analysis was used for statistical analysis of experimental results.Results:Eight nucleotides GCAGGTCA were found to have inserted into the 400-401th ORF of DRD5 in both the spasmodic torticollis subgroup and the control group.This experiment found for the first time the existence of genotype in DRD5.Among the respective 25 cases in the patient group and the control group collected for the experiment,both groups show,respectively,21 cases with genotypes in which 8 nucleotides were inserted.Among them,4 cases were DRD5 genotype in NCBI template,with x2 =0.149 and p>0.05,and the difference was not statistically significant.It could thus be concluded that mutation was common in both the spasmodic torticollis subgroup and the control group.There are many mutations in ORF of DRD5.For example:a A?4G mutation at position 877 and 1299;a C?T mutation at position 1096;a T?C mutation at position 1099;a A?G mutation at position 1229;a G?A mutation at position 1268 and 1269.These differences are statistically significant.The OR of 877th is 3.273,and the OR95%confidence interval for 1.008?10.621.The OR of 1199th is 3.431,and the OR95%confidence interval for 1.026?11.476.The two sites may be risk factors for spasmodic torticollis.But the OR at position 1096?1229?1268 and 1269 is 0.291,and the OR95%confidence interval for 0.087?0.975,these four sites may be protective factors.A G?A mutation at 23rd inpoints on ORFof DRD5 lead Glycine change into Aspartic acid.A C?T mutation at 75th inpoints on ORFof DRD5 lead a Silent mutation—Asparagine.A G?A mutation at 181th inpoints on ORFof DRD5 lead Valine change into Methionine.A C?Tmutation at 199th inpoints on ORFof DRD5 lead Arginine change into Tryptophan.A G?Amutation at the 249th inpoints on ORFof DRD5 lead a Silent mutation—Leucine.A G?C mutation at the 250th inpoints on ORF of DRD5 lead Alanine change into ProLine.A C?T mutation at the 286th inpoints on ORFof DRD5 lead ProLine change into Serine.A C?T mutation at the 318th inpoints on ORP of DRD5 lead a Silent mutation—Tyrosine.Eight nucleotides were found to have inserted into the 400-401th lead to a Frameshift mutation.finally,there is a termination codon at the 436-435th,protein translation termination.Variations of these amino acids are not statistically significant.Conclusion:1.This study shows a high rate of mutation in DRD5.2.There are six SNP mutations in ORF of DRD5.These differences are statistically significant,and may be related to spasmodic torticollis:two of it are may be risk factors and four are protective factors.3.The SNP mutations on ORF of DRD5 lead a Frameshift mutation and five missense mutations.finally,there is a termination codon at the 436-435th,protein translation termination.