array type, some assays perform poorly, and some common SNPs are not or cannot be tagged.Improved methods will be needed to provide more systematic information about CNVs and their relationship to disease. Associated CNV regions will require resequencing studies of large numbers of subjects without CNVs, to determine whether these regions also contain rare, highly penetrant associated variants.There are probably unknown genetic mechanisms. We have only recently recognized the importance of CNVs, micro RNAs, long-range promoters and epigenetic factors (genomic effects other than sequence changes, such as DNA methylation patterns). (75) The discovery that most of the genome is transcribed suggests that many types of functional sequence are undiscovered. (12)
