The PEDF gene is a member of the serpin gene family. Serpins are a group of serine protease inhibitors, some of which have also been reported to exhibit neurotrophic activity.By the analysis of 3 independent somatic cell hybrid panels, Tombran-Tink et al. (1994) assigned the PEDF gene to chromosome 17. Fluorescence in situ hybridization showed localization at the terminal portion of 17p. PCR analysis of somatic cell hybrids containing specific regions of 17 were subsequently used to sublocalize PEDF to 17pter-p13.1. Greenberg et al. (1997) used linkage analysis to narrow the localization of the PEDF gene to 17p13.3, the same region as that carrying the autosomal dominant retinitis pigmentosa locus (RP13) identified in a South African family.