Rapid, comprehensive analysis of the dystrophin transcript by a custom micro-fluidic exome array

Duchenne and Becker muscular dystrophies are caused by mutations in the dystrophin gene. Both the enormous size of this gene and heterogeneous set of causative mutations behind these pathologies may hamper and even prevent accurate molecular diagnosis. Often RNA analysis is required not only to identify mutations escaping MLPA/CGH or exon sequencing but also to validate the functional effect of novel variations that may affect the exon composition of the DMD gene. We present the design and experimental validation of a new, simple, and easy-to-use platform we call FluiDMD. This platform is based on the Applied Biosystems 7900HT TaqMan(®) low-density array technology and is able to define the full-exon composition, profile the dystrophin isoforms present, establish changes in mRNA decay, and potentially identify all deletions/duplications and splicing affecting mutations contemporaneously. Moreover, we demonstrate that this system accurately detects the pathogenic effect of all dystrophin mutations belonging to any category, thereby highlighting the functional validation capacity of this system. The high efficacy and sensitivity of this tool in detecting mutations in the dystrophin transcript can be exploited in a variety of cells/tissues, in particular skin, which is harvested by causing minimum patient discomfort. We therefore propose FluiDMD as a validated diagnostic biomarker for molecular profiling of dystrophinopathies.