Diagnostic testing for dystonia
The Paediatric Neurology Department at the Hospital Vall d’Hebron is specialised in the genetic diagnosis of childhood neurological diseases. It participates in different national and European reference networks (like the URDCat Project, Solve-RD, and the European Reference Network for Rare Neurological Diseases), which centralises a large number of paediatric patients with hereditary dystonia. The genetic studies are carried out in the Paediatric Neurology Laboratory as part of several different research studies, which are funded by national and international entities as well as associations of families affected by dystonia.
Patients who are likely to suffer from dystonia undergo different metabolic, neurophysiological, and neuroimaging tests in order to classify what kind of dystonia they have, before carrying out genetic studies. Next, DNA sequencing studies are performed to establish the genetic origin of the dystonia.
What is it used for?
To determine the origin of the patient’s dystonia, which is essential for deciding on a correct course of treatment.
How is it performed?
There are many different genetic origins of dystonia. Therefore, diagnosing it requires both conventional and newly developed DNA sequencing techniques.
For patients with myoclonus-dystonia, first, Sanger sequencing is done for the epsilon-sarcoglycan gene, which is responsible for 70% of myoclonus-dystonia cases in children.
For patients with other kinds of dystonia, whole-exome sequencing (on the parents and the patient) or sequencing for the index case (the patient) is done first, depending on the DNA samples available.
Risks
There are no risks for the patient.