Dystonia related to the GCH1 gene presented with motor and nonmotor symptoms

Abstract

Background: Dopa-responsive dystonia (DRD) comprises a group of monogenic disorders with a frequently challenging diagnosis. Clinical manifestations include both motor and non-motor symptoms, the latter often being underrecognized.

Case report: A 50-year-old woman presented with involuntary movements of the feet (dystonia), leading to progressive gait impairment, without diurnal fluctuation. She also had a history of chronic recurrent depression since childhood. Genetic testing confirmed DRD. Treatment with L-dopa and fluoxetine resulted in satisfactory symptom control.

Discussion: DRD is commonly caused by mutations in GCH1, affecting tetrahydrobiopterin synthesis, a cofactor essential for catecholamine production, which explains both motor and psychiatric manifestations related to this condition.

Conclusion: We emphasize the importance of investigating non-motor symptoms in DRD, considering that this can lead to greater morbidity related to this condition, requiring specific treatment.