functional significance by virtue of its influence on the expression of this gene. This polymorphism therefore joins the ranks of the hitherto relatively small number of human intronic SNPs located outwith exon-intron splice junctions that have been shown by various methods of in vitro characterisation to be of direct functional significance. Table 1 lists some of the best characterised examples of such functional SNPs, most of which are located at least ~30 base pairs (bp) from the nearest splice site. These SNPs have been shown to influence either the transcriptional activity or the splicing efficiency of their host genes, or instead to alter the expression of alternative transcripts.
