Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular disorder characterized primarily by progressive degeneration and necrosis of skeletal muscle, resulting from mutations in the Dystrophin gene. Patients with DMD typically present with progressive muscle weakness and atrophy during childhood. Currently, available treatment options for DMD remain limited and their efficacy is suboptimal. This review aims to provide a systematic overview of recent advances in therapeutic strategies for DMD, including an analysis of the mechanisms underlying various treatment approaches, outcomes from clinical trials, and their potential clinical applications, in order to inform and guide clinical decision-making.
Muscular Dystrophy, Duchenne/genetics* ; Humans ; Genetic Therapy

Duchenne muscular dystrophy (DMD) is an X-linked recessive myopathy caused by mutations in the dystrophin gene, which is divided into presymptomatic, early ambulatory, late ambulatory, early non-ambulatory, and late non-ambulatory stages according to its disease progression. Some patients experience non-progressive cognitive developmental delays in the presymptomatic stage. DMD patients gradually develop osteoporosis, cardiomyopathy, decreased respiratory function, delayed puberty, and gastrointestinal symptoms as the disease progresses. The required multidisciplinary management strategies vary across different disease stages. To standardize the multidisciplinary management of DMD, we established the DMD Guideline Writing Committee under the authorization of Chinese Medical Association Rare Disease Branch. Combined with the questions raised by patients in multiple consultations, neuromuscular experts drafted the DMD guidelines based on published clinical evidence, current practices, and expert recommendations. A consensus was reached on the best-practice recommendations for DMD management after extensive consultations with specialists from multiple relevant disciplines. The resulting recommendations have been endorsed by Chinese Medical Association Rare Disease Branch. This guideline provides practical and reasonable recommendations for all healthcare professionals and caregivers involved in DMD management, ensuring that patients can receive high-standard medical treatment and care across our country, which also serves as a reference for government staff involved in DMD management.
Humans ; Muscular Dystrophy, Duchenne/therapy* ; China

OBJECTIVE

Our study aimed to determine the clinical profile and pulmonary function of pediatric patients with Duchenne Muscular Dystrophy (DMD). We also characterized the stages of progression of the disease and determined their potential association with spirometry variables.

In this cross-sectional study, we used data obtained from a review of medical records of all pediatric patients (0-18 years old) with DMD seen in a multidisciplinary neuromuscular clinic of a tertiary government hospital from August 2018 until March 2020.

Included were 30 patients subdivided into groups according to the stage of disease progression. Overweight (26.7%), obesity (20%), and scoliosis (26.7%) were common among non-ambulatory patients. Only one late ambulatory patient had evidence of ineffective airway clearance. Symptoms of sleep-disordered breathing, particularly snoring (66.7%) and apnea (6.7%), were common across all disease stages. All patients had normal peripheral oxygen saturation on room air. The mean peak expiratory flow rate was 215.6 (±84) L/min. The mean Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), and FEV1/FVC were 66.2% (±23.7), 67.7% (±23.8), and 97.5 (±3.2), respectively. Among patients with polysomnography results, the average apnea-hypopnea index (AHI) per hour was 3 (±1.6). When patients were compared according to their stage disease progression, however, no significant differences exist.

This is the first study on the pulmonary function of Filipino pediatric patients with DMD. Spirometry patterns characteristic of restrictive lung disease were observed. Prospective studies may help identify respiratory variables that significantly correlate with pulmonary function.

Objective: To analyze the clinical and genetic characteristics of pediatric patients with dual genetic diagnoses (DGD). Methods: Clinical and genetic data of pediatric patients with DGD from January 2021 to February 2022 in Peking University First Hospital were collected and analyzed retrospectively. Results: Among the 9 children, 6 were boys and 3 were girls. The age of last visit or follow-up was 5.0 (2.7,6.8) years. The main clinical manifestations included motor retardation, mental retardation, multiple malformations, and skeletal deformity. Cases 1-4 were all all boys, showed myopathic gait, poor running and jumping, and significantly increased level of serum creatine kinase. Disease-causing variations in Duchenne muscular dystrophy (DMD) gene were confirmed by genetic testing. The 4 children were diagnosed with DMD or Becker muscular dystrophy combined with a second genetic disease, including hypertrophic osteoarthropathy, spinal muscular atrophy, fragile X syndrome, and cerebral cavernous malformations type 3, respectively. Cases 5-9 were clinically and genetically diagnosed as COL9A1 gene-related multiple epiphyseal dysplasia type 6 combined with NF1 gene-related neurofibromatosis type 1, COL6A3 gene-related Bethlem myopathy with WNT1 gene-related osteogenesis imperfecta type XV, Turner syndrome (45, X0/46, XX chimera) with TH gene-related Segawa syndrome, Chromosome 22q11.2 microduplication syndrome with DYNC1H1 gene-related autosomal dominant lower extremity-predominant spinal muscular atrophy-1, and ANKRD11 gene-related KBG syndrome combined with IRF2BPL gene-related neurodevelopmental disorder with regression, abnormal movement, language loss and epilepsy. DMD was the most common, and there were 6 autosomal dominant diseases caused by de novo heterozygous pathogenic variations. Conclusions: Pediatric patients with coexistence of double genetic diagnoses show complex phenotypes. When the clinical manifestations and progression are not fully consistent with the diagnosed rare genetic disease, a second rare genetic disease should be considered, and autosomal dominant diseases caused by de novo heterozygous pathogenic variation should be paid attention to. Trio-based whole-exome sequencing combining a variety of molecular genetic tests would be helpful for precise diagnosis.
Humans ; Abnormalities, Multiple ; Retrospective Studies ; Intellectual Disability/genetics* ; Bone Diseases, Developmental/complications* ; Tooth Abnormalities/complications* ; Facies ; Muscular Dystrophy, Duchenne/complications* ; Muscular Atrophy, Spinal/complications* ; Carrier Proteins ; Nuclear Proteins

Female ; Humans ; Muscular Dystrophy, Duchenne/genetics*

Humans ; Muscular Dystrophy, Duchenne/epidemiology* ; Prevalence ; Myocardium

Dystrophinopathies, including Duchenne muscular dystrophy, Becker muscular dystrophy and dilated cardiomyopathy, are X-linked recessive genetic disorders due to variants of the dystrophin gene, which can seriously affect quality of life and health. Genetic diagnosis plays a crucial role in their diagnosis, treatment, and prevention. How to rationally select and standardize the use of various genetic techniques is a skill that clinicians must acquire. By compiling expertise of experts from the relevant areas and guidelines published home and abroad, this consensus has provided a guidance from the perspective of genetic diagnosis for the selection of genetic techniques, testing strategies, and detection process for dystrophinopathies.
Humans ; Quality of Life ; Consensus ; Dystrophin/genetics* ; Muscular Dystrophy, Duchenne/therapy* ; Cardiomyopathy, Dilated/genetics* ; Electrocardiography

OBJECTIVE: To explore the correlation between clinical manifestations of Limb-girdle muscular dystrophy autosomal recessive 9 FKRP-related (R9 FKRP-related) and variants of the FKRP gene. METHODS: Two children who had presented at the Children's Hospital of Nanjing Medical University respectively due to increased serum myocardial zymogram and hepatic dysfunction on September 30, 2018 and August 3, 2018 were selected as the study subjects. Clinical data of the children were collected. Both children were suspected for Duchenne or Becker muscular dystrophy for asymptomatic high creatine kinase (CK) levels. Peripheral blood samples of the children and their parents were collected for whole exome sequencing, and candidate variants were validated by Sanger sequencing. RESULTS: Genetic testing revealed that both children have carried compound heterozygous variants of the FKRP gene. The c.545A>G and c.941C>T variants in child 1 have been reported previously, among which the c.545A>G is a hot spot mutation in the Chinese population. Child 2 has carried c.602T>C and c.961G>A variants, both of which were unreported previously. CONCLUSION Both children have met the diagnostic criteria for LGMD R9 FKRP-related. Carriers of the c.545A>G variant may present milder symptoms. Compared with patients carrying null variants, carriers of compound heterozygous missense variants may present with a milder phenotype, manifesting as asymptomatic high CK level.
Humans ; Child ; Asian People/genetics* ; Genetic Testing ; Muscular Dystrophies, Limb-Girdle/genetics* ; Muscular Dystrophy, Duchenne ; Pentosyltransferases/genetics*

OBJECTIVE: To explore the genetic basis for 7 families with gonadal mosaicism for Duchenne muscular dystrophy (DMD). METHODS: For the 7 families presented at the CITIC Xiangya Reproductive and Genetic Hospital from September 2014 to March 2022, clinical data were collected. Preimplantation genetic testing for monogenic disorders (PGT-M) was carried out for the mother of the proband from family 6. Peripheral venous blood samples of the probands, their mothers and other patients from the families, amniotic fluid samples from families 1 ~ 4 and biopsied cells of embryos cultured in vitro from family 6 were collected for the extraction of genomic DNA. Multiplex ligation-dependent probe amplification (MLPA) was carried out for the DMD gene, and short tandem repeat (STR)/single nucleotide polymorphism (SNP)-based haplotypes were constructed for the probands, other patients, fetuses and embryos. RESULTS: The results of MLPA showed that the probands and the fetuses/probands' brothers in families 1 ~ 4, 5, 7 had carried the same DMD gene variants, whilst the probands' mothers were all normal. The proband in family 6 carried the same DMD gene variant with only 1 embryo (9 in total) cultured in vitro, and the DMD gene of the proband's mother and the fetus obtained through the PGT-M were normal. STR-based haplotype analysis showed that the probands and the fetuses/probands' brothers in families 1 ~ 3 and 5 have inherited the same maternal X chromosome. SNP-based haplotype analysis showed that the proband from family 6 has inherited the same maternal X chromosome with only 1 embryo (9 in total) cultured in vitro. The fetuses in families 1 and 6 (via PGT-M) were both confirmed to be healthy by follow up, whilst the mothers from families 2 and 3 had chosen induced labor. CONCLUSION Haplotype analysis based on STR/SNP is an effective method for judging gonad mosaicism. Gonad mosaicisms should be suspected for women who have given births to children with DMD gene variants but with a normal peripheral blood genotype. Prenatal diagnosis and reproductive intervention may be adapted to reduce the births of further affected children in such families.
Male ; Pregnancy ; Child ; Humans ; Female ; Muscular Dystrophy, Duchenne/diagnosis* ; Dystrophin/genetics* ; Mosaicism ; Exons ; Prenatal Diagnosis/methods* ; Nucleotides

Humans ; Muscular Dystrophy, Duchenne/diagnosis* ; Cardiomyopathy, Dilated/diagnosis* ; Echocardiography ; Patients