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Pennings, R.

Publications and source records attributed to Pennings, R..

2 recordsLinked to original sources

Antisense oligonucleotide-based treatment of retinitis pigmentosa caused by USH2A exon 13 mutations

Mutations in USH2A, encoding usherin, are the most common cause of syndromic and non-syndromic retinitis pigmentosa (RP). The two founder mutations in exon 13 (c.2299delG and c.2276G>T) collectively account for ~34% of USH2A-associated RP cases. Skipping of exon 13 from the USH2A transcript during pre-mRNA splicing presents a potential treatment modality in which the resulting transcript is predicted to encode a slightly shortened usherin protein. Morpholino-induced skipping of ush2a exon 13 in larvae of the previously published ush2a exon 13 zebrafish mutant resulted in the production of usherin{Delta}exon13 and completely restored retinal function. RNA antisense oligonucleotides were investigated for their potential to specifically induce human USH2A exon 13 skipping. Lead candidate QR-421a induced dose-dependent exon 13 skipping in iPSC-derived photoreceptor precursors from a patient homozygous for the USH2A c.2299delG mutation. Intravitreal delivery of QR-421a in non-human primates showed that QR-421a penetrates the retinal outer nuclear layer and induces detectable levels of exon 13 skipping until at least 3 months post injection. In conclusion, QR-421a-induced exon skipping proves to be a highly promising treatment for RP caused by mutations in exon 13 of the USH2A gene.

genetics

Allele-specific antisense oligonucleotide therapy for dominantly inherited hearing impairment DFNA9.

The c.151C>T founder mutation in COCH is a frequent cause of late onset, dominantly inherited hearing impairment and vestibular dysfunction (DFNA9) in the Dutch/Belgian population. The initial clinical symptoms only manifest between the 3rd and 5th decade of life, which leaves ample time for therapeutic intervention. The dominant inheritance pattern and established non-haploinsufficiency disease mechanism indicate that suppressing translation of mutant COCH transcripts has high therapeutic potential. Single-Molecule Real-Time (SMRT) sequencing resulted in the identification of 11 variants with a low population-frequency (< 10%), that are specific to the c.151C>T mutant COCH allele. Proof of concept was obtained that gapmer antisense oligonucleotides (AONs), directed against the c.151C>T mutation or mutant allele-specific intronic variants, are able to specifically induce mutant COCH transcript degradation when delivered to transgenic cells expressing COCH minigenes. Sequence optimization of the AONs against the c.151C>T mutation resulted in a lead molecule that reduced the levels of mutant COCH transcripts by ~60% in a transgenic cell model, without affecting wildtype COCH transcript levels. With the proven safety of AONs in humans, and rapid advancements in inner ear drug delivery, our in-vitro studies indicate that AONs offer a promising treatment modality for DFNA9.

genetics