Exome Sequencing and Optical Genome Mapping in Molecularly Unsolved Cases of Duchenne Muscular Dystrophy: Identification of a Causative X-Chromosomal Inversion Disrupting the IDMD/I Gene

Duchenne muscular dystrophy (DMD) is a severe progressive muscle disease that mainly affects boys due to X-linked recessive inheritance. In most affected individuals, MLPA or sequencing-based techniques detect deletions, duplications, or point mutations in the dystrophin-encoding DMD gene. However,...

Full description

Saved in:
Bibliographic Details
Published inInternational journal of molecular sciences Vol. 24; no. 19
Main Authors Erbe, Leoni S, Hoffjan, Sabine, Janßen, Sören, Kneifel, Moritz, Krause, Karsten, Gerding, Wanda M, Döring, Kristina, Güttsches, Anne-Katrin, Roos, Andreas, Buena Atienza, Elena, Gross, Caspar, Lücke, Thomas, Nguyen, Hoa Huu Phuc, Vorgerd, Matthias, Köhler, Cornelia
Format Journal Article
LanguageEnglish
Published MDPI AG 01.09.2023
Subjects
Analysis
DNA sequencing
Duchenne muscular dystrophy
Dystrophin
Gene mutations
Genes
Genomes
Genomics
Health aspects
Nucleotide sequencing
Utrophin
Germany
Online AccessGet full text

Cover

More Information
Summary:Duchenne muscular dystrophy (DMD) is a severe progressive muscle disease that mainly affects boys due to X-linked recessive inheritance. In most affected individuals, MLPA or sequencing-based techniques detect deletions, duplications, or point mutations in the dystrophin-encoding DMD gene. However, in a small subset of patients clinically diagnosed with DMD, the molecular cause is not identified with these routine methods. Evaluation of the 60 DMD patients in our center revealed three cases without a known genetic cause. DNA samples of these patients were analyzed using whole-exome sequencing (WES) and, if unconclusive, optical genome mapping (OGM). WES led to a diagnosis in two cases: one patient was found to carry a splice mutation in the DMD gene that had not been identified during previous Sanger sequencing. In the second patient, we detected two variants in the fukutin gene (FKTN) that were presumed to be disease-causing. In the third patient, WES was unremarkable, but OGM identified an inversion disrupting the DMD gene (~1.28 Mb) that was subsequently confirmed with long-read sequencing. These results highlight the importance of reanalyzing unsolved cases using WES and demonstrate that OGM is a useful method for identifying large structural variants in cases with unremarkable exome sequencing.
ISSN:1422-0067
1422-0067
DOI:10.3390/ijms241914716