Background: There are few reports on the relationship of transforming growth factor-β1 (TGF-β1) and asthma. This study was undertaken to explore the association of TGF-β1 gene polymorphism with asthma in children.

Mothods: Ninety-eight children with asthma and 52 normal children were enrolled. The TGF-β1 gene -509C/T polymorphism in the 5’-flanking region was detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The total serum IgE level was examined by the sandwich ELISA method.

Results: No significant differences were found in genotype distribution and allele frequencies between asthmatic individuals and normal controls. But significant differences were seen among severe asthma, mild asthma and normal controls. The serum IgE levels of TT genotype in asthmatic individuals were higher than those of CC or CT genetype.

Conclusions: TGF-β1-509C/T gene mutation is not a high risk factor of asthma, but it is closely correlated with asthma severity, and could be one of candidate genes in severe asthma. The level of serum total IgE is related to TGF-β1-509C/T gene mutation homozygotes.