Several genes have been identified in different groups of patients and by different teams, but the results have not been replicated in the different population groups studied. Although the disorders of people with essential tremor are very similar, the current hypothesis is that there is no single cause of essential tremor, with heterogeneity in the causes and in the course from one person to another. There are also sporadic (isolated) cases of the disease, i.e. patients with no family history. Genetic research has shown that there is a genetic predisposition to the disease, meaning that certain DNA variants increase the risk of developing the disease but are not hereditary.
The risk of an affected person carrying an autosomal dominant mutation passing on the mutation, and therefore the disease, to their child is therefore 50%.
There are also sporadic cases of the disease, i.e. patients with no family history. Genetic research has shown that there is a genetic predisposition to the disease, meaning that certain DNA variants increase the risk of developing the disease but are not hereditary.
The biological mechanisms behind essential tremor are partially understood. Current research tells us that brain circuits linked to the cerebellum, the brain region involved in controlling movements and their precision, play a role in the disease. The cerebellum also has the function of coordinating movements and stabilising balance, so over time patients may develop greater difficulty in coordinating the actions of their upper limbs, and present balance problems when walking.
Modulation of cerebellar circuits is the basis of treatments such as deep brain stimulation of the thalamus (a structure at the heart of the cerebellar circuit), or highly focused lesioning of a small area of the thalamus using gamma rays (Gamma-knife) or focused ultrasound (FUS).