To elicit the silencing effect, ESSs recruit proteins that will negatively affect the core splicing machinery.
The single stranded pre-mRNA molecules need to have their intronic and exonic regions spliced in order to be translated.
ESSs have four general roles:[2] Myotonic dystrophy (MD) is most noticeably caused by inheriting an unstable CTG triplet expansion in the DMPK gene.
Isoform IR-B contains exon 11 and is expressed in cells of the liver, muscles, kidney, and adipocytes.
In individuals with MD, IR-A is upregulated in high amounts in skeletal muscle leading to the disease phenotype.
[4] The ESS nucleotide sequence exists within intron 10 and is thought to be dependent on the CUG triplet repeat in order to silence the splicing of exon 11.
This transition point mutation leads to the exclusion of exon 7 from the mRNA transcript, it is also the only difference between the SMN2 and SMN1 gene.