Asthma is one of the most common
chronic diseases in childhood. It is well known that genetic variability contributes to
asthma risk. One of the most replicated
asthma candidate genes is ORM1-like 3 (Saccharomyces cerevisiae) (ORMDL3), which has been associated with childhood
asthma susceptibility. Another
asthma candidate gene is
signal transducer and activator of transcription 6 (STAT6), a regulator of
IgE class switching. Gene coding
thromboxane A2 receptor (TBXA2R), involved in chronic airway
inflammation, has been associated with
asthma in several genetic studies. We have studied the association of polymorphism rs4795405 in ORMDL3, rs324011 in STAT6 as well as rs8113232 and rs3786989 in TBXA2R with
asthma risk, various
asthma phenotypes and
asthma-related symptoms. The study group consisted of 154 children with
asthma, in whom clinical parameters were measured and whose
asthma control and atopic status were determined. A control group comprised 71 healthy children. Genotyping was performed using an allelic discrimination assay. The ORMDL3 polymorphism rs4795405 was suggestively associated with
asthma risk. Furthermore, it was significantly associated with nonatopic
asthma and
asthma without
rhinitis. No association was detected between the STAT6 polymorphism rs324011 or the TBXA2R polymorphisms rs8113232 and rs3786989 and
asthma susceptibility. However, an association between rs324011 in STAT6 with recurrent
wheezing in early childhood and a suggestive association between rs8113232 in TBXA2R with
rhinitis in children with
asthma were observed. Our results confirmed ORMDL3 as a candidate gene for childhood
asthma susceptibility. STAT6 and TBXA2R polymorphisms were not associated with
asthma risk, but they were associated with
asthma-related symptoms.