SERPINA1 and allergic asthma: However, no significant association was observed between common SERPINA1 SNPs and the risk of developing school‐age asthma, the presence of a deficient allele (S or Z) did not affect the risk of wheezing in childhood and further development of asthma in adolescence41, and no association was made between AATD genotypes or lung function severity with allergic asthma severity40.