Novel missense variant in the TMEM151A gene causing paroxysmal kinesigenic dyskinesia: a case report with literature review

Background Paroxysmal kinesigenic dyskinesia (PKD) is a rare movement disorder with high clinical and genetic heterogeneity. Proline-rich transmembrane protein 2 ( PRRT2 ) was identified as the first causative gene for PKD in 2011. Recently, heterozygous variants in transmembrane protein 151A ( TMEM151A ) were identified as another pathogenic cause of PKD. Case description A 16-year-old man diagnosed with PKD exhibited hemidystonia triggered by sudden voluntary movements. His mother also had similar symptoms since the age of 20. Whole-exome sequencing revealed a likely pathogenic missense variant (c.892 T > C) in the TMEM151A gene. At the same time, we reviewed the literature focusing on the molecular characteristics and the clinical phenotypes in patients with TMEM151A variants, especially within the same family. Conclusion This case further validated the pathogenic role of TMEM151A variants in PKD. The findings of interfamilial and intrafamilial variability in the phenotypes expanded our understanding of TMEM151A -related PKD.