A recurrent COL6A1 pseudoexon insertion causes muscular dystrophy and is effectively targeted by splice-correction therapies

JCI Insight. 2019 Mar 21;4(6):e124403. doi: 10.1172/jci.insight.124403.


The clinical application of advanced next-generation sequencing technologies is increasingly uncovering novel classes of mutations that may serve as potential targets for precision medicine therapeutics. Here, we show that a deep intronic splice defect in the COL6A1 gene, originally discovered by applying muscle RNA sequencing in patients with clinical findings of collagen VI-related dystrophy (COL6-RD), inserts an in-frame pseudoexon into COL6A1 mRNA, encodes a mutant collagen α1(VI) protein that exerts a dominant-negative effect on collagen VI matrix assembly, and provides a unique opportunity for splice-correction approaches aimed at restoring normal gene expression. Using splice-modulating antisense oligomers, we efficiently skipped the pseudoexon in patient-derived fibroblast cultures and restored a wild-type matrix. Similarly, we used CRISPR/Cas9 to precisely delete an intronic sequence containing the pseudoexon and efficiently abolish its inclusion while preserving wild-type splicing. Considering that this splice defect is emerging as one of the single most frequent mutations in COL6-RD, the design of specific and effective splice-correction therapies offers a promising path for clinical translation.

Keywords: Collagens; Extracellular matrix; Muscle Biology; Neuromuscular disease; Therapeutics.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • CRISPR-Cas Systems
  • Collagen Type VI / genetics*
  • DNA Mutational Analysis
  • Exons / genetics
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Gene Expression
  • Genetic Predisposition to Disease / genetics*
  • Genetic Therapy / methods
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Introns / genetics
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / therapy*
  • Mutation
  • RNA Splice Sites
  • RNA Splicing*
  • RNA, Messenger / metabolism
  • Skin / pathology


  • Col6a1 protein, human
  • Collagen Type VI
  • RNA Splice Sites
  • RNA, Messenger