Searching for potential microRNA-binding site mutations amongst known disease-associated 3′ UTR variants

The 3′ untranslated regions (3′ UTRs) of human protein-coding genes play a pivotal role in the regulation of mRNA 3′ end formation, stability/degradation, nuclear export, subcellular localisation and translation, and hence are particularly rich in cis-acting regulatory elements. One recent addition to the already large repertoire of known cis-acting regulatory elements are the microRNA (miRNA) target sites that are present in the 3′ UTRs of many human genes. miRNAs post-transcriptionally down-regulate gene expression by binding to complementary sequences on their cognate target mRNAs, thereby inducing either mRNA degradation or translational repression. To date, only one disease-associated 3′ UTR variant (in the SLITRK1 gene) has been reported to occur within a bona fide miRNA binding site. By means of sequence complementarity, we have performed the first systematic search for potential miRNA-target site mutations within a set of 79 known disease-associated 3′ UTR variants. Since no variants were found that either disrupted or created binding sites for known human miRNAs, we surmise that miRNA-target site mutations are not likely to represent a frequent cause of human genetic disease.