Background: A recent genome-wide association study of Thai patients with thyrotoxic periodic paralysis (TPP) identified a novel genetic variant rs623011 located in chromosome 17q24.3, which may potentially reduce the transcription of Kir2.1 and total Kir current.
Purpose: The aim of this study was to evaluate whether this genetic variant was present in Chinese patients with TPP and sporadic periodic paralysis (SPP), the second leading cause of non-familial hypokalemic periodic paralysis (hypoKPP) in Asia.
Methods: Ninety patients with TPP, 61 SPP, and 100 age and sex-matched healthy subjects were performed. Genomic DNA was isolated from blood leukocytes and analysis of rs623011 was performed by polymerase chain reaction and direct sequencing.
Results: Compared with normal control, the frequency of the risk allele A of rs623011 was significantly higher in both TPP and SPP patients (73.9% versus 53.5%, p=0.001; 82.0% versus 53.5%, p<0.001, respectively) with the Odds ratios (95% confidence interval) 2.426 (1.348-4.369) and 4.488 (2.265-8.891), respectively. The frequency of the A allele of rs623011 was similar between TPP and SPP.
Conclusions: TPP and SPP have the same susceptible gene variant rs623011 and may share the pathogenic mechanism of reduced Kir current in skeletal muscle independent of thyroid hormone.
Copyright © 2012 Elsevier B.V. All rights reserved.