# De novo p.Glu61Ter mutation in GCH1 in a Moroccan patient with dopa-responsive dystonia: a case report

## TL;DR

A Moroccan patient with dopa-responsive dystonia was found to have a new mutation in the GCH1 gene, highlighting the role of genetic sequencing in diagnosing rare hereditary disorders.

## Contribution

This is the first reported case of dopa-responsive dystonia in Morocco with a de novo p.Glu61Ter mutation in the GCH1 gene.

## Key findings

- A de novo p.Glu61Ter mutation in the GCH1 gene was identified in a Moroccan patient with dopa-responsive dystonia.
- The mutation was validated through gene panel sequencing and Sanger sequencing.
- The case emphasizes the importance of next-generation sequencing in diagnosing hereditary movement disorders.

## Abstract

Dopa-responsive dystonia (DRD) is a hereditary movement disorder due to a selective nigrostriatal dopamine deficiency. It is characterized by onset in childhood or adolescence with marked diurnal fluctuation with or without Parkinsonian features, and is caused by mutations in GCH1 gene. We report in this study the clinical and genetic features of the first DRD Moroccan patient. Using a gene panel sequencing, we identified a heterozygous nonsense variant p. Glu61Ter in GCH1. A subsequent targeted segregation analysis by Sanger sequencing validated the presence of the mutation in the patient, which was found to have occurred de novo. The objective of this study is to report the first description of DRD in Morocco, and highlights the importance of new generation sequencing technology in the reduction of medical wandering and the management of hereditary diseases.