Investigation of the genetic factors underlying asthma and atopy in outbred UK populations

Both asthma and atopy run families indicating a strong genetic component. T o investigate possible candidate gene regions, we have recruited 131 famili es without reference to atopy and asthma (random sample) and 60 extended fa milies with two or more members affected by asthma (multiplex sample). Usin g both candidate and genome screen approaches, we have been able to provide evidence supporting the presence of candidate genes on chromosome 11q (E23 7G) and 12q but we have been linable to confirm reports of linkage and asso ciation for asthma on 5q. Our experience to date suggests that larger numbe rs of families are needed to increase the confidence of gene localisation a nd there is a need to improve the phenotypic description of asthma. Finally , it is essential that claims for linkage or association are confirmed in d ifferent populations using the same markers.