Objective: To investigate the link between the polymorphism of -109 and Glu237 in the high-affinity IgE receptor beta (FcepsilonRIbeta) gene and susceptibility to allergic asthma in a Chinese population.
Method: Blood samples from 216 allergic asthma patients and 198 age- and sex-matched controls were studied. A -109C/T and a coding variant Glu237Gly in FcepsilonRIbeta were detected with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results: The genotype frequencies were 0.403 for -109T/T, 0.491 for -109T/C and 0.106 for -109C/C in allergic asthma in a Chinese population. No significant difference in the distribution of -109C/T polymorphism was found between allergic asthma subjects and healthy controls, however, homozygosity for the -109T allele was associated with increased total plasma IgE levels in subjects with allergic asthma (F = 4.020, P < 0.05). The allele frequency of Gly237 in the patients and control was 0.236 and 0.136 respectively. There was a significant association between the Gly/Gly genotype and allergic asthma. Among allergic asthma patients Gly237 was significantly associated with high IgE levels.
Conclusions: These results suggest that the Gly237 variant of the FcepsilonRIbeta gene is involved in the development of allergic asthma. The -109C/T and Glu237Gly polymorphisms are two of the genetic factor identified thus far, which affect total plasma IgE levels of allergic asthma patients in a Chinese population.