Abstract
SUMMARYMutations in the fukutin-related protein (FKRP) gene result in a broad spectrum of muscular dystrophy (MD) phenotypes, including the severe Walker-Warburg syndrome (WWS). Here, we develop a gene-editing approach that replaces the entire mutant open reading frame with the wild-type sequence to universally correct all FKRP mutations. We apply this approach to correct FKRP mutations in induced pluripotent stem (iPS) cells derived from patients displaying broad clinical severity. Our findings show rescue of functional α-dystroglycan (α-DG) glycosylation in gene-edited WWS iPS cell-derived myotubes. Transplantation of gene-corrected myogenic progenitors in the FKRPP448L-NSG mouse model gives rise to myofiber and satellite cell engraftment and, importantly, restoration of α-DG functional glycosylation in vivo. These findings suggest the potential feasibility of using CRISPR-Cas9 technology in combination with patient-specific iPS cells for the future development of autologous cell transplantation for FKRP-associated MDs.
Highlights
Mutations in fukutin-related protein (FKRP) are associated with muscular dystrophies (MDs) of remarkably variable clinical severity, ranging from mild limb-girdle muscular dystrophy (MD) type 2I (LGMD2I, known as LGMDR9) to severe forms of congenital MD (CMD), including Walker-Warburg syndrome (WWS) and muscle-eye-brain disease (MEB) (Beltran-Valero de Bernabeet al., 2004; Mercuri et al, 2003; Topaloglu et al, 2003)
In vitro phenotype of FKRP mutant patient-specific induced Pluripotent stem (PS) (iPS) cell-derived myotubes FKRP mutant iPS cell lines were generated from three patients displaying broad clinical severity
Cells were generated from a WWS patient, CDI73 iPS cells were derived from a LGMD2R9 patient, and FP3 iPS cells were generated from a patient with an intermediate phenotype LGMDR9/CMD
Summary
Mutations in fukutin-related protein (FKRP) are associated with muscular dystrophies (MDs) of remarkably variable clinical severity, ranging from mild limb-girdle MD type 2I (LGMD2I, known as LGMDR9) to severe forms of congenital MD (CMD), including Walker-Warburg syndrome (WWS) and muscle-eye-brain disease (MEB) (Beltran-Valero de Bernabeet al., 2004; Mercuri et al, 2003; Topaloglu et al, 2003). Besides FKRP, mutations in several other genes directly involved in a-DG glycosylation, such as POMT1, POMT2, LARGE, and FKTN, result in different forms of dystroglycanopathies (Beltran-Valero de Bernabeet al., 2002; Martin, 2007). The gene correction of a-sarcoglycan (Tedesco et al, 2012), dystrophin (Young et al, 2016), and calpain 3 (Selvaraj et al, 2019a) mutant patient-specific iPS cells led to the rescue of phenotype, suggesting the potential for autologous cell-based therapy in these MDs. Despite these
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
