5-Lipoxygenase pathway gene polymorphisms: lack of association with asthma in a Spanish population.

BACKGROUND Cysteinyl-leukotrienes are mediators of inflammatory responses in bronchial asthma. We studied the genes encoding the enzymes involved in their synthesis to identify risk factors for asthma. The promoter polymorphisms LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 have been reported to be associated with bronchial asthma. METHODS We analyzed the effects of LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 on asthma susceptibility by means of a case-control study with 193 ethnically matched, unrelated individuals. Participants were classified as severe asthmatics, nonsevere asthmatics, and nonasthmatics, using a combination of 2 techniques: polymerase chain reaction-restricted fragment length polymorphism and multiplex capillary electrophoresis. RESULTS No association was found between these polymorphisms and asthma, neither individually nor in combination. CONCLUSION Although the studied polymorphisms have been previously reported to constitute risk factors for the disease, we found no association between LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 polymorphisms and bronchial asthma.