Variations in genetic influences on the development of asthma throughout childhood, adolescence and early adult life.

PURPOSE OF REVIEW

Asthma is likely to be due to many aetiological factors, the effect of each varying considerably with age. Now that there are well established candidate genes for asthma, using genetics to examine age-related susceptibility to asthma offers a new approach to understanding the basic underlying mechanisms.

RECENT FINDINGS

Since few long-term, longitudinal asthma studies exist, opportunities to examine age-related genetic susceptibility have been limited, but have produced some specific findings. The CCR5Delta32 polymorphism renders the chemokine receptor nonfunctional and is associated with reduced asthma susceptibility in children but not adults. In CD14 C-159T, the -159C allele has been associated with increased atopy in mid-childhood, but not in young adults. IL-12beta is a promoter polymorphism associated with reduced lung function in girls but not boys in mid-childhood only. Regarding the beta(2)adrenoceptor, results from three studies suggest that Arg16 can be associated with impaired airway function in infancy and Gly16 with asthma and wheeze in mid-childhood.

SUMMARY

Age-related genetic susceptibility studies are likely to make a major contribution to understanding basic mechanisms in asthma, but the limited number of suitable cohorts has meant that to date few studies have been reported.