This article discusses a case study of a 57-year-old Han Chinese male with dopa-responsive dystonia (DRD) caused by a large inversion affecting the GCH1 gene. The patient experienced abnormal head posturing and gait disturbance following a head injury at age 10. Despite not having an identifiable disease-causing variant through conventional gene sequencing, the patient responded well to low-dose levodopa treatment. The study highlights the importance of using whole genome sequencing, nanopore long-read sequencing, and optical genome mapping to detect and confirm complex structural variants in patients with DRD. [Extracted from the article]