Objective: Objective: Two sisters with a diagnosis of dopa-responsive dystonia (DRD) with a new mutation are reported.
Background: Background: GTP cyclohydrolase I (GCH1) mutations are the most common cause of DRD. DRD is an autosomal dominant with an estimated incidence of between 0.5 and 1 per million. DRD typically manifests as lower limb dystonia in childhood, although the spectrum of symptoms can be broad, even within the same family. Patients typically have an excellent and sustained response to low dose levodopa.
Method: Methods: Case 1: A 38-year-old female patient is diagnosed with dystonic cramps in the left leg and inability to walk. Her complaints started at the age of 7 and gradually increased. She has been mobilized with a wheelchair since the age of 15. While she was better in the mornings, her complaints increased in the afternoons. Neurological examination: Revealed dystonic posture in the left leg, she could not stand up without support and could not be mobilized. Case 2: A 29-year-old female patient is diagnosed with dystonic cramps in the legs (left> right) and inability to walk. Her complaints started at the age of 9 and gradually increased. She has been mobilized with a wheelchair since the age of 14. While she was better in the mornings, her complaints increased in the afternoons. Neurological examination: Revealed dystonic posture in the legs and left arm, she could not stand up without support and could not be mobilized.
Results: Results: There were no pathological findings in laboratory and MRI examinations. Genetic examination of both sisters revealed compound heterozygous (c.175>G (p.59G) (p. Arg59gly) / c.304A>C (p.M102L) in GCH1 gene.
Conclusion: Conclusion: p.M102L variant of GHC1 gene is a novel one that needs to be studied in the family members without any clinical findings. Also, a parental screening should be assessed to clarity the cis/trans position of both variants. All family members are being screened for this novel mutation and its relationship with DRD will be reported later.
To cite this abstract in AMA style:
M. Demirkiran, M. Balal, A. Bisgin. Sisters with a novel compound heterozygous mutation in GCH1 gene linked to dopa responsive dystonia [abstract]. Mov Disord. 2022; 37 (suppl 2). https://www.mdsabstracts.org/abstract/sisters-with-a-novel-compound-heterozygous-mutation-in-gch1-gene-linked-to-dopa-responsive-dystonia/. Accessed June 14, 2025.« Back to 2022 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/sisters-with-a-novel-compound-heterozygous-mutation-in-gch1-gene-linked-to-dopa-responsive-dystonia/