Pooled linkage results in schizophrenia and localization of genes related to glial growth factors and synaptic strength. Data compiled from 60 published (not abstracts) linkage studies in schizophrenia (including two studies using endophenotypes of the disorder) [73, 74, 146–203]. Each dot represents evidence for linkage obtained in an independent sample. The level of significance is shown according to the criteria of Lander and Kruglyak . Red indicates significant (lod score = 3.6), yellow suggestive (lod score = 2.2) evidence and white hints (p ≤ 0.05) for linkage. Only the marker showing the best evidence for linkage in the region were used from each study. Markers within a distance of 20 Megabases (Mb) are displayed at the same chromosomal position. The distance between linkage marker and gene in Mb is given below the gene. Chromosomal positions were obtained from the Unified Database for Human Genome Mapping (UDB)  and the UCSC Human Genome Project Working Draft http://genome.ucsc.edu. A susceptibility gene within a distance of 20 Mb from a genetic marker can be detected by linkage analysis. The marker-gene distances range from 0.1 to 19.1 (median 1.7) Mb.