Abstract:

Objective · To study the clinical and genetic features of familial paroxysmal exercise-induced dyskinesia (PED) in a Chinese mainland family, and review the advances of clinical and genetic studies on PED.  Methods · The clinical information of 7 family members in one Chinese pedigree, including 5 patients and 2 healthy people, was analyzed and the patients’ response to treatment and prediction were followed up. The SLC2A1 gene in all 7 members of this family was sequenced. The clinical and genetic characteristics of 5 patients were analyzed. Advances of recent clinical and genetic studies related with PED were further reviewed.  Results · Among the total 5 patients (male : female=1:4), four patients had pure form of PED, and one patient had PED plus epilepsy. Attacks of the proband and his daughter could not be well controlled by carbamazepine or sodium valproate. In addition, three patients showed a remission trend with age advancing. In this family, the SLC2A1 c.C284T (p.S95L) was identified in all 5 patients, but not in 2 healthy members. According to the American College of Medical Genetics and Genomics (ACMG) criteria and guideline, the variant SLC2A1 c.C284T (p.S95L) was classified as “pathogenic variant”.  Conclusion · PED is a rare paroxysmal movement disorder with highly phenotypic heterogeneity as well as a remission trend with age advancing. This paper reviews advances in clinical and genetic studies on PED recently, in order to contribute to the clinical diagnosis and appropriate treatment of PED.

Key words: paroxysmal exercise-induced dyskinesia, clinical features, genetics, SLC2A1, epilepsy