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Genome scans in Icelandic, Australian and New Zealand, and Finnish families have localized putative susceptibility loci for preeclampsia! eclampsia to chromosome 2. The locus mapped in the Australian and New Zealand study (designated PREG 1) was thought to be the same locus as that identified in the Icelandic study. In both these studies, two distinct quantitative trait locus (QTL) regions were evident on chromosome 2. Here, we descdbe our fine mapping of the PREG 1 locus and a genetic analysis of two positional candidate genes. Twenty-five additional microsatellite markers were genotyped within the 74-cM linkage region defined by the combined Icelandic and Australian and New Zealand genome scans. The overall position and shape of the localization evidence obtained using non parametric multipoint analysis did not change from that seen previously in our lO-cM resolution genome scan; two peaks were displayed, one on chromosome 2p at marker D2S388 (107.46 cM) and the other on chromosome 2q at 151.5 cM at marker D2S23l3. Using the robust two-point linkage analysis implemented in the Analyze program, all 25 markers gave positive LOD scores with significant evidence of linkage being seen at marker D2S2313 (151.5 cM), achieving a LOD score of 3.37 under a strict diagnostic model. Suggestive evidence of linkage was seen at marker D2S388 (107.46 cM) with a LOD score of 2.22 under the general diagnostic model. Two candidate genes beneath the peak on chromosome 2p were selected for further analysis using public single nucleotide polymorphisms (SNPs) within these genes. Maximum LOD scores were obtained for an SNP in TACRI (LOD = 3.5) and for an SNP in TCF7Ll (LOD = 3.33), both achieving genome-wide significance. However, no evidence of association was seen with any of the markers tested. These data strongly support the presence of a susceptibility gene on chromosome 2p11-12 and substantiate the possibility of a second locus on chromosome 2q23.