Positive association to IgE levels and a physical map of the 13q14 atopy locus.

Linkage of atopy and associated traits to a locus on chromosome 13q14 has been identified by several studies in diverse populations. We have previously shown the putative atopy gene to be contained within an interval of approximately 5 Mb flanked by D13S328 and D13S1269 and centred on D13S273. We have now extended this work using a top-down approach to physical mapping. A YAC contig was constructed covering the D13S328 and D13S1269 interval. Thirty-one ESTs were mapped to the contig. We constructed a BAC and PAC contig flanking D13S273 by approximately 750 kb in either direction. The interval contained 27 of the 31 ESTS from the YAC contig. Seven previously unknown microsatellites were recovered and then typed in two subject panels. A positive association between the total serum Immunoglobulin E concentration and the novel USAT24G1 microsatellite was discovered (P(corrected)<0.005) and replicated in a second panel of families. The discovery of a region of positive association within the BAC/PAC contig will permit identification of the atopy gene from this locus.