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Muscle biopsy grading. Gastrocnemius biopsy with HE staining in wild type (Wt), BMD (#18F, #17F), and DMD (#6M, #7M, #3M) patients. Wt=muscle fibers in fascicular arrangement, uniform muscle fiber diameters, peripherally-located nuclei, and without lymphocyte infiltration, fat infiltration, fibrosis, or necrosis. DMD/ BMD=variable muscle fiber diameters, increased centrally-located nuclei, lymphocyte infiltration, fibrosis, and fat infiltration, categorized as grades 1, 2, 3, and 4.
Source publication
Background Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic X-linked recessive diseases caused by mutations in the dystrophin (DMD) gene. To our knowledge, molecular analysis to differentiate between DMD and BMD has never been performed in Indonesia.
Objective To elaborate the clinicopathologic and molecular profil...
Context in source publication
Context 1
... biopsy samples were histopathologically assessed using standard HE staining by a trained pathologist (Figure 1). The specimens showed variations in muscle fiber diameter size, increased centrally-located nuclei, necrosis, lymphocyte infiltration, fat replacement, and fibrosis in 18/18, 14/18, 13/18, 17/18, 18, and 15/18 patients, respectively ( Table 2). ...
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Duchenne muscular dystrophy is a severe, X-linked, progressive neuromuscular disorder clinically characterised by muscle weakening and extremely high serum creatine kinase levels. A 1-year-old Chinese patient was diagnosed with early-onset Duchenne muscular dystrophy. Next-generation gene sequencing was conducted and the Sanger method was used to v...
A 29-year-old female presented with an elevated level of serum creatine kinase without subjective weakness. Neurologic examination showed the subtle motor weakness of the right arm. Muscle biopsy showed dystrophic changes and a mosaic pattern of dystrophin expression. The diagnosis was confirmed by multiplex ligation-dependent probe amplification a...
Dystrophinopathy is a spectrum of muscular dystrophies resulting from absolute to relative deficiency of dystrophin - a protein essential for muscle fiber integrity. This includes a severe form called Duchenne muscular dystrophy, a mild form called Becker muscular dystrophy, and intermediate muscular dystrophy. Becker muscular dystrophy relates to...
Citations
... Prior to the MLPA technique, approaches such as multiplex PCR using primers that cover sets of commonly deleted exons would yield deletion rates ranging from 40% to 51.2% of DMD/BMD cases as reported in some Asian populations. 17 DMD gene analysis in the Indonesian population has been conducted previously using IHC 18 and multiplex PCR 19 methods. However, precise mutations cannot be identified using the IHC method while multiplex PCR is unable to cover all exons in the DMD gene. ...
... This is due to difficulty in getting access to molecular testing. Muscle biopsy can be performed to help with diagnosis using immunohistochemistry analysis, 18 however, not all medical centers have this facility and not all parents agree to this invasive procedure. Due to such limitations in Indonesia, the disease has not been well characterized. ...
Background
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations in the DMD gene. The full mutation spectrum of the DMD gene in Indonesian patients is currently unknown. Mutation-specific therapies are currently being developed, such as exon skipping or stop codon read-through therapy. This study was conducted with the aim of identifying the mutation spectrum of the DMD gene in Indonesia to guide future development and application of feasible therapeutic strategies.
Methods
This study is a cross sectional study that enrolled 43 male patients with a clinical suspicion of DMD or BMD. Multiplex ligation-dependent probe amplification (MLPA) reaction was performed to screen for the common mutations in the DMD gene.
Results
Out of 43 subjects, deletions accounted for 69.77% (n=30) cases, while duplications were found in 11.63% (n=5) cases. One novel duplication spanning exons 2 to 62 was identified. Deletion mutations clustered around the distal (66.67%) and proximal (26.67%) hot spot regions of the DMD gene while duplication mutations were observed solely at the proximal region. Two false positive cases of single exon deletion detected through MLPA were attributed to sequence mutations affecting primer ligation sites, confirming the need to validate all single exon deletions when using this screening method. Analysis of available maternal DNA samples showed that the rate of de novo mutations (48.15%) appears higher than expected in this population. Out of 31 patients who were classified as DMD based on clinical and genotype characterizations, 60.47% (n=26) of cases were suitable for exon skipping therapy.
Conclusion
This is the first comprehensive study showing the feasibility of implementing the MLPA method for routine screening of DMD patients in Indonesia. This is also the first study showing the potential applicability of exon skipping therapy in the majority of DMD cases in the country.
