Association between renin-angiotensin system gene polymorphism and recurrent wheezing in Chinese children: a 4-year follow-up study.

This study aimed to clarify the association between angiotensin-converting enzyme (ACE) gene polymorphisms and infant wheezing, and to determine whether an association may contribute to early prediction of persistent wheezing and asthma. The study cohort comprised 149 patients with asthma, 169 patients with wheezing but no clinical diagnosis of asthma and 165 healthy control subjects. The insertion/deletion (I/D) polymorphism of the ACE gene was determined by polymerase chain reaction. Total serum immunoglobulin E was determined for the wheezy group and a 4-year follow-up study was carried out to observe wheezing relapse. Significant differences were found between patients and controls in allele frequency and genotype distribution. The DD genotype was more frequent in patients in the wheezing and asthma groups than in the control subjects. Patients with the DD genotype had a higher frequency of relapse than patients expressing the ID or II genotypes. It is concluded that the DD genotype of ACE is a risk factor for recurrent wheezing in early childhood.