RNA sequencing facilitates the identification of genetic causes of Duchenne muscular dystrophy and proposes a stepwise DMD diagnostic procedure.

A certain percentage of Duchenne muscular dystrophy (DMD) patients remain genetically undiagnosed after routine genetic testing. Accurate genetic diagnosis is crucial for determining eligibility for mutation-specific therapies and providing relatives with reliable genetic and reproductive counselling. In this study, we utilized RNA sequencing to achieve precise genetic diagnoses in three DMD patients. We identified a deep intronic variant, NC_000023.11:g. 32644691A>C (NM_004006.3:c.1149+273T>G), responsible for creating a novel exon in one patient. An abnormal splicing event was also observed in the second patient. Additionally, RNA sequencing of the pathological muscle samples revealed differentially expressed genes. Based on these findings, we proposed a comprehensive, stepwise diagnostic procedure for DMD. Our study suggests that RNA sequencing can be instrumental in diagnosing disease-causing intronic variants, and the proposed procedure aims to enhance the clarity and accuracy of genetic diagnoses in DMD.