After genetic variants associated with diseases or parameters have been identified, it is important to establish their specific gene localization and, consequently, their functional effects. To this end, several tools, such as the Ensembl Variant Effect Predictor (VEP),105 are now available. However, since the localization of a variant may be different in different isoforms of the same gene, the variant can be predicted to map in UTRs (in one isoform) as well as in introns, in non-sense mediated decay (NMD) or non coding transcripts, in regulatory regions, in transcription factors (TF) binding sites or even outside the gene (in alternative isoforms) (figure 2). This introduces an extra layer of complexity in genetic data interpretation.
