Systematic evaluation of single nucleotide polymorphisms (SNPs) and patients with childhood onset asthma have revealed that genetic variants regulating ORMDL3 expression may alter susceptibility to asthma [167].Orosomucoid-like (ORMDL) proteins act as negative regulators of SPT that are mediated by a feedback response, thus increased levels of the ORMDL proteins result in a decrease in ceramide and higher order sphingolipid biosynthesis as a result of inhibited de novo sphingolipid synthesis [168, 169]. This evidence concerns the gene AGXT and asthma.