# A Case of Familial Paroxysmal Non-kinesigenic Dyskinesia in Mainland China: A Clinical and Genetic Investigation

## TL;DR

This paper reports a large Chinese family with a rare movement disorder called PNKD and identifies a specific genetic mutation linked to the condition.

## Contribution

The study presents a rare Asian PNKD family with a confirmed c.20C4T mutation, expanding the known genetic and clinical spectrum of the disorder.

## Key findings

- Nine affected family members share the c.20C4T (p.Ala7Val) mutation in the PNKD gene.
- The study contributes to the understanding of PNKD's clinical and genetic variability in Asian populations.
- The findings offer new insights for diagnosing this rare neurological condition.

## Abstract

Paroxysmal non-kinesigenic dyskinesia (PNKD) is an autosomal dominant condition characterized by recurring dystonia or mixed chorea and ballism caused by emotional stress, exhaustion, coffee, alcohol, menstruation, and other factors. Here, we provide a large family PNKD pedigree from mainland China, where the same c.20C4T (p.Ala7Val) mutation in exon 1 of the PNKD gene was genetically confirmed to be present in nine affected individuals. Here, we report a rarely described Asian PNKD pedigree and aim to widen the clinical and genetic spectrum of PNKD while also providing fresh diagnostic insights for this rare condition.