Cervical dystonia is associated with a polymorphism in the dopamine (D5) receptor gene

The objective was to assess whether polymorphisms in the dopamine receptor and transporter genes are associated with development of primary cervical d ystonia. A case-control allelic association study is described of 100 patie nts with cervical dystonia and 100 controls using polymorphisms within D1-5 receptor and dopamine transporter genes. No significant association was found between patient and control allele fre quencies for polymorphisms in genes for the D1 to 4 receptors and dopamine transporter. Significant associations, however, were found for alleles 2 an d 6 of the D5 receptor micosatellite. Carriage of allele 2 was associated w ith cervical dystonia, whereas allele 6 was overrepresented in the control group, implying a possible protective effect. The association with allele 6 remained significant after Bonferroni correction. In conclusion, the finding of a significant association with an allele in t he D5 receptor gene in patients with cervical dystonia may indicate a patho genic role of this gene (or neighbouring genes). Further studies are requir ed to confirm this finding and to assess whether these alleles are part of distinct haplotypes associated with other polymorphisms imparting a functio nal effect on the D5 receptor.