Detailed mechanisms have not yet been fully studied; however, all the infants who have maternally inherited the FcεRI-L181 allele revealed a higher incidence of atopy than those with the I181 and homozygous FcεRI–L/L181 and L/L183 genotypes showed a higher prevalence in asthma, compared with the counterpart genotype [77,78,79]. This evidence concerns the gene FCER1A and asthma.