00 Pseudoexon activation an underreported disease mechanism with a unique potential for targeted intervention

Project: Research

Project Details


Introns make up approx. 90% of a gene and harbor the majority of the sequence variation in our genome. Introns in all genes harbor pseudoexons, which are normally suppressed and not spliced into the functional mRNA. By affecting splicing regulatory elements (SREs) intronic SNPs and mutations may cause inclusion of pseudoexons.
Based on our own data and an increasing number of publications describing this pseudoexon activation, we believe that this disease mechanism is frequently involved in disease, but heavily underreported due to the misconception that intronic sequence variations are neutral, that patient RNA is not analyzed, that pseudoexon inclusion often leads to mRNA degradation and because SREs are difficult to recognize.
Our preliminary data show that normal pseudoexons, which are not activated, but known to cause disease when activated by point mutations, can be detected by Next Generation
Sequencing of RNA (RNA-seq) in control cells. We will therefore use RNA-seq for global detection of pseudoexons, establish a database and use this to identify potential disease associated functional SNPs in pseudoexons.
We have patient cells, minigenes and methods allowing characterization of the pseudoexon activation mechanism in selected disease genes. We will test SNPs located in new pseudoexons identified by RNA-seq.
We have shown that disease causing pseudoexon inclusion can be corrected in cells from patients with MTRR-deficiency by splice shifting oligonucleotides (SSOs). We believe that this approach is uniquely suited for specific, personalized therapy also in other diseases caused by pseudoexon activation. We will investigate the general rules underlying successful SSO-based correction of the MTRR- and other disease associated pseudoexons in more detail.
The present project will contribute important knowledge about the frequency of this disease mechanism, the basic rules determining pseudoexon activation and the rules for successful SSObased splicing correction.
Effective start/end date01/01/201431/12/2016