Arg16Gly polymorphism in beta2-adrenergic receptor gene is not associated with thyrotoxic periodic paralysis in Korean male patients with Graves' disease.

BACKGROUND

Thyrotoxic periodic paralysis (TPP) occurs most frequently in Asian males and present with an acute episode of proximal muscle weakness in the setting of thyrotoxicosis. Despite the fact that mutations were described in genes encoding ion channels in familial hypokalaemic periodic paralysis, no definite genetic variants were found in TPP. beta2-adrenergic receptors (ADRB2s) are expressed in skeletal muscle and stimulate the sodium pump. Single nucleotide polymorphisms in ADRB2 gene were identified and may act as disease modifiers in various diseases.

OBJECTIVE

We were to demonstrate that ADRB2 gene might be a susceptibility gene for TPP in Korean male patients with Graves' disease.

DESIGN AND PATIENTS: In a series of 28 male TPP patients and 31 control patients, three polymorphisms in ADRB2 gene have been studied: a T to C substitution at -47 (-47T/C), Arg16Gly and Gln27Glu. Control patients were male Graves' patients without history of paralysis.

RESULTS

The distributions of the -47C, Gly16 and Glu27 alleles in all patients were 0.02, 0.34 and 0.02, respectively. The genotype Arg16/Arg16 was not significantly associated with TPP (odds ratio 0.53; 95% confidence interval, 0.19-1.50; corrected P = 0.897). Also, the frequency of genotype Gly16/Gly16 was not significantly different in TPP patients than in controls (0.07 vs. 0.23; odds ratio, 0.26; 95% confidence interval, 0.05-1.40; corrected P = 0.45). Allele frequencies of ADRB2 in patients with TPP did not differ from controls.

CONCLUSIONS

The polymorphism of the ADRB2 gene may not confer genetic susceptibility to TPP in Korean male patients with Graves' disease.