Analysis of over 7,000 DMD mutations reveals that 80% are large mutations and identifies significant proportions potentially amenable to novel genetic therapies like exon skipping.
Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http: //umd. be/TREATDMD/). We analyzed genetic data for 7, 149 DMD mutations held within the database. A total of 5, 682 large mutations were observed (80% of total mutations), of which 4, 894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1, 445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0. 3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations).
Bladen et al. (2015) studied this question.