Graphical view (Integrated Genomics Viewer) of read distribution across a gene and an exon . (a,b) Gene (a) and exon (b) annotations shown are from the primary representative RefSeq annotations. The exome design encompasses a unified set of exon annotations from NCBI, Ensembl and VEGA; therefore, there are regions with high coverage, representing exons that are not shown in the primary RefSeq annotation (red arrow) but are represented in Ensembl and/or VEGA. Typical coverage across exons includes sufficient read depth to call single nucleotide variants in coding sequence and in neighboring splice acceptor and donor sites, as well as 20 to 50 bases of additional flanking intron sequence (b).
Fairfield et al. Genome Biology 2011 12:R86 doi:10.1186/gb-2011-12-9-r86