Tanya Stojkovic, Rahul Phadke, Rabah Ben Yaou, Pascal Sabouraud, Andoni Urtizberea, Joana Domingos, Matthew J Ellis, Adam Jones, Deborah M. Eastwood, Domenic Scaglioni, D. Chambers, Jennifer E Morgan, Tracey Willis, Silvia Torelli, Enzo Ricci, Lucy Feng, Maud Beuvin, Valentina Sardone, Giorgio Tasca, Francesco Muntoni, Caroline Sewry, Christine Barnerias, Gisèle Bonne, R. Kulshrestha, Great Ormond Street Institute of Child Health [London, UK] (UCL), University College of London [London] (UCL), Great Ormond Street Hospital for Children NHS Foundation Trust [London, UK], Great Ormond Street Hospital for Children [London] (GOSH), Service de biochimie et de génétique moléculaire [CHU Cochin], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Cochin [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut de Myologie, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Association française contre les myopathies (AFM-Téléthon)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Centre de Recherche en Myologie, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Centre de référence des maladies rares neuromusculaires, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Hôpital Marin d'Hendaye, Centre Hospitalier Universitaire de Reims (CHU Reims), CHU Necker - Enfants Malades [AP-HP], Università cattolica del Sacro Cuore [Roma] (Unicatt), Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Fondazione Policlinico Universitario Agostino Gemelli IRCCS [Rome], Institute of Neurology - UCL/Queen Square [London, UK] (IN-UCL-QS), University of Southampton, Great Ormond Street Institute of Child Health (UCL), Great Ormond Street Hospital for Children NHS Foundation Trust [London, UK] (GOSHC), Centre de recherche en Myologie – U974 SU-INSERM, Università cattolica del Sacro Cuore = Catholic University of the Sacred Heart [Roma] (Unicatt), Fondazione Policlinico Universitario Agostino Gemelli IRCCS, UCL Institute of Neurology, Queen Square [London], and Centre National de la Recherche Scientifique (CNRS)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Association française contre les myopathies (AFM-Téléthon)-Sorbonne Université (SU)
Duchenne muscular dystrophy (DMD) is an incurable disease caused by out-of-frame DMD gene deletions while in frame deletions lead to the milder Becker muscular dystrophy (BMD). In the last decade several antisense oligonucleotides drugs have been developed to induce a partially functional internally deleted dystrophin, similar to that produced in BMD, and expected to ameliorate the disease course. The pattern of dystrophin expression and functionality in dystrophinopathy patients is variable due to multiple factors, such as molecular functionality of the dystrophin and its distribution. To benchmark the success of therapeutic intervention, a clear understanding of dystrophin expression patterns in dystrophinopathy patients is vital. Recently, several groups have used innovative techniques to quantify dystrophin in muscle biopsies of children but not in patients with milder BMD. This study reports on dystrophin expression using both Western blotting and an automated, high-throughput, image analysis platform in DMD, BMD, and intermediate DMD/BMD skeletal muscle biopsies. Our results found a significant correlation between Western blot and immunofluorescent quantification indicating consistency between the different methodologies. However, we identified significant inter- and intradisease heterogeneity of patterns of dystrophin expression in patients irrespective of the amount detected on blot, due to variability in both fluorescence intensity and dystrophin sarcolemmal circumference coverage. Our data highlight the heterogeneity of the pattern of dystrophin expression in BMD, which will assist the assessment of dystrophin restoration therapies.