Keegan NP, Wilton SD, Fletcher S. Breakpoint junction features of seven DMD deletion mutations. Human genome variation 2019;6:39
Duchenne muscular dystrophy is an inherited muscle wasting disease with severe symptoms and onset in early childhood. Duchenne muscular dystrophy is caused by loss-of-function mutations, most commonly deletions, within the DMD gene. Characterizing the junction points of large genomic deletions facilitates a more detailed model of the origins of these mutations and allows for a greater understanding of phenotypic variations associated with particular genotypes, potentially providing insights into the deletion mechanism. Here, we report sequencing of breakpoint junctions for seven patients with intragenic, whole-exon DMD deletions. Of the seven junction sequences identified, we found one instance of a “clean” break, three instances of microhomology (2-5 bp) at the junction site, and three complex rearrangements involving local sequences. Bioinformatics analysis of the upstream and downstream breakpoint regions revealed a possible role of short inverted repeats in the initiation of some of these deletion events.