Gross deletions intragenic (exon-level deletions).

Mutational mechanisms are not the same for all diseases. There are some diseases in which deletions are more frequent than point mutations.

Intragenic deletions (deletions the size of an exon) can be difficult to identify using current sequencing techniques, and may also go undetected by aCGH technology (depending on probe density).

Intragenic deletions are of particular importance from a therapeutic standpoint, as in some cases they are candidates for exon-skipping therapy (exon-skipping).