A limited number of genes, including the human brain-derived neutrotrophic factor (BDNF) gene, have been identified in the human chromosome 11p14 region. Since this area is involved in a genetic disorder (WAGR syndrome) and because of interest in studying the regulation of the human BDNF gene, we have established a detailed transcript map of a 810-kb region clone in a yeast artificial chromosome (YAC), corresponding to a portion of this genomic locus. A set of nested deletion mutants has been generated to map genes at a mean resolution of 75kb. Four genic markers from available mapping databases have been mapped on the YAC. Ten potential novel human exons have been isolated by a 3' terminal exon trapping procedure directly applied to purified YAC DNA. Most of these exons display polyadenylation signals and they all yield positive signals in RT-PCR experiments, confirming their status of transcribed sequences. The BDNF gene is now co-localised with three other genes on a 120 kb DNA fragment.