The relevant characteristics of each study included in the GSMA are summarized in Table 1. For each study, the following information was extracted: first author, journal, year of publication, ethnicity of study population, number of families, subjects, definition of phenotype, number of markers, linkage statistic, and software used for linkage analysis. If the genomewide linkage results were available from the published graphs, the required linkage statistics for GSMA were extracted from the figures by the digital software g3data (http://www.frantz.fi/software/g3data.php). Otherwise, the authors were invited to contribute the whole genome linkage results including marker names, genetic position and linkage statistics for each marker. The authors of five studies including seven genome scans (7, 13–16) provided the original linkage results. Genetic map positions and marker locations were unified based on the Marshfield genetic map.
