How should we go about increasing the number of identified functional intronic polymorphisms? One approach would be to employ exon-tiling microarrays to perform genome-wide scans to identify intronic SNPs responsible for inter-individual differences in the splicing phenotype [11,14,15]. Since currently available bioinformatics tools are inadequate to the task of predicting splicing consequences,[14] however, all SNPs identified in this way would have to be further validated using mini-gene constructs to determine the resulting splicing phenotype [14]. One feature that might prove helpful in identifying intronic SNPs is that such variants are often located within gene regions that are characterised by a reduced level of genetic variation [16].
