Screening of mutations in GNAL in sporadic dystonia patients.

Background: GNAL mutations have been shown to cause adult-onset isolated dystonia, a disabling movement disorder characterized by involuntary muscle contractions causing twisting and repetitive movements or abnormal postures.

Methods: To test the frequency of GNAL mutations in a series of 137 German patients with sporadic dystonia patients we used next-generation sequencing of amplicon-derived barcoded NexteraXT libraries for the coding exons and adjacent intronic sequences of GNAL.

Results: In our cohort we identified 1 pathogenic nonsense mutation (c.733C>T, p.R245*) in a patient with cervical dystonia. In a second patient a synonymous coding nonsynonymous variant (c.G252A, p.E84E) was detected, which is predicted to alter a splice site.

Conclusions: Our findings further support GNAL as causative gene in adult-onset isolated dystonia.