New gene for hyperkinesia discovered

Good news for people who suffer from the combination of chorea (unintentional dancing movement of the arms, legs, torso and/or face) and dystonia (unintentional repetitive movements in a fixed pattern that can cause abnormal posture). A few genes were already known to cause the combination of chorea and dystonia, but researchers at UMCG have discovered a new gene: the DRD2 gene. 'The gene provides insight into the underlying biology of chorea and dystonia and how this overactivity is inherited within families,' says Marlous van der Weijden of the Movement Disorders Expertise Center at UMCG. 

Overactive dopamine receptor
The researchers from UMCG, in collaboration with researchers from the Oregon Health & Science University in America and the Universitätsklinikum Tuebingen in Germany, looked at the consequences of mutations in the DRD2 gene. 'Mutations affect the functioning of the DRD2 gene in brain cells, changing its function,' says van der Weijden. 'The DRD2 gene is translated into a dopamine receptor that is important for communication between brain cells. Carriers of the mutation in the DRD2 gene have a dopamine receptor that remains active. This ultimately most likely causes the hyperactivity.' 

The discovery of this gene offers opportunities for treatment of people with a combination of chorea and dystonia, the researchers argue. For this, more research is needed.