biostudies-literaturePoyatos-Garcia JFundación Isabel Gemio793-806https://www.ebi.ac.uk/biostudies/studies/S-EPMC9825930biostudies-literatureUnknown92(5)<h4>Objective</h4>Duchenne muscular dystrophy (DMD) exon 45-55 deletion (del45-55) has been postulated as a model that could treat up to 60% of DMD patients, but the associated clinical variability and complications require clarification. We aimed to understand the phenotypes and potential modifying factors of this dystrophinopathy subset.<h4>Methods</h4>This cross-sectional, multicenter cohort study applied clinical and functional evaluation. Next generation sequencing was employed to identify intronic breakpoints and their impact on the Dp140 promotor, intronic long noncoding RNA, and regulatory splicing sequences. DMD modifiers (SPP1, LTBP4, ACTN3) and concomitant mutations were also assessed. Haplotypes were built using DMD single nucleotide polymorphisms. Dystrophin expression was evaAnnals of neurologyDystrophinopathy Phenotypes and Modifying Factors in DMD Exon 45-55 Deletion.PMC98259302018/0200Gamez JAladren JANieto MAzorin IRodriguez BBarcena JEPoyatos-Garcia JVilchez RDiaz-Manera JGallano PSelva-Gimenez MMontolio MMartinez-Dolz LJauregui ACasasus AMarti PLiquori AMuelas NSevilla THervas DVilchez JJDamia MFernandez AGonzalez-Quereda LAller EPitarch IAlonso-Perez JfalseDystrophinopathy Phenotypes and Modifying Factors in DMD Exon 45-55 Deletion.<h4>Objective</h4>Duchenne muscular dystrophy (DMD) exon 45-55 deletion (del45-55) has been postulated as a model that could treat up to 60% of DMD patients, but the associated clinical variability and complications require clarification. We aimed to understand the phenotypes and potential modifying factors of this dystrophinopathy subset.<h4>Methods</h4>This cross-sectional, multicenter cohort study applied clinical and functional evaluation. Next generation sequencing was employed to identify intronic breakpoints and their impact on the Dp140 promotor, intronic long noncoding RNA, and regulatory splicing sequences. DMD modifiers (SPP1, LTBP4, ACTN3) and concomitant mutations were also assessed. Haplotypes were built using DMD single nucleotide polymorphisms. Dystrophin expression was eva2022-01-01T00:00:00Z2022 Nov2026-03-27T15:40:14.284Z2025-04-05T10:26:51.065ZS-EPMC98259303589713810.1002/ana.26461