Pseudoexon exclusion by antisense therapy in methylmalonic aciduria (MMAuria)

✍ Scribed by B. Pérez; A. Rincón; A. Jorge-Finnigan; E. Richard; B. Merinero; M. Ugarte; L.R. Desviat

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 287 KB
• Volume: 30
• Category: Article
• ISSN: 1059-7794
• DOI: 10.1002/humu.21118

✦ Synopsis

Development of pseudoexon exclusion therapies by antisense modification of pre-mRNA splicing represents a type of personalized genetic medicine.

Here we present the cellular antisense therapy and the cell-based splicing assays to investigate the effect of two novel deep intronic changes c.1957-898A4G and c.1957-920C4A identified in the methylmalonyl-coenzyme A (CoA) mutase (MUT) gene. The results show that the nucleotide change c.1957-898A4G is a pathological mutation activating pseudoexon insertion and that antisense morpholino oligonucleotide (AMO) treatment in patient fibroblasts leads to recovery of MUT activity to levels 25 to 100% of control range. On the contrary, the change c.1957-920C4A, identified in two fibroblasts cell lines in cis with c.1885A4G (p.R629G) or c.458T4A (p.D153V), appears to be a rare variant of uncertain clinical significance. The functional analysis of c.1885A4G and c.458T4A indicate that they are the disease-causing mutations in these two patients. The results presented here highlight the necessity of scanning the described intronic region for mutations in MUTaffected patients, followed by functional analyses to demonstrate the pathogenicity of the identified changes, and extend previous work of the applicability of the antisense approach in methylmalonic aciduria (MMAuria) for a novel intronic mutation.