The Effect of a Genetic Polymorphism of TNF-α on Clinical Abnormalities Associated with a Mutant β₃-Adrenergic Receptor

Abstract

The polymorphism in the tumor necrosis factor-α (TNF-α, G to A at position-308) and β₃-adrenergic receptor (13-AR. W64R) genes have been suggested to be associated with obesity and insulin resistance. We examined the frequency and clinical influence of a G to A polymorphism in the TNF-α gene among Japanese subjects. We also examined whether simultaneous occurrence of the polymorphism in the β₃-AR and TNF-α genes has any effect on clinical characteristics or BMI values. The frequency of the G to A polymorphism of the TNF-α gene was found to be very low among Japanese (TNF1, n=287; TNF2, n=8), and we could not find any differences in the clinical data from the two genotypes. Subjects homozygous for the W64R allele in the β₃-AR gene showed significantly higher BMI, serum FBG, GGT and LAP levels than those without the mutation, the clinical characteristics of a subject with the TNF2 gene and the W64R polymorphism of the β₃-AR gene were not markedly different from those of subjects with the W64R polymorphism alone.