The UMD-DMD France mutations database
Impact of deletions on the reading frame

The DMD gene is composed of 79 exons that are distributed in various phases (to view the exons' phasing map of the DMD gene, go to the search page). When a deletion occurs, it can result into a frameshift and therefore lead to a premature stop codon. This is achieved when two exons in different phases are joined end to end (for example exons 51 and 53). When two exons in the same phase are involved, it is usually assumed that no premature stop codon is generated Nevertheless, this does not take into account the impact at the junctional codon. The list below gives the impact on reading frame of all possible deletions of one or more exons taking into account the impact at the junctional codon.
For example del51-58 (c.7310_8668del) produces at the junction a stop codon while the two exons are in the same frame.

First deleted exon	Last deleted exon	Impact	Impact at the junction
0	0	Out of frame del	-