Duchenne muscular dystrophy is the most common inherited neuromuscular disorder in childhood and remains associated with delayed diagnosis in many Latin American settings. We conducted a retrospective observational cohort study of 74 boys with genetically or muscle biopsy-confirmed Duchenne muscular dystrophy evaluated at the National Institute of Pediatrics in Mexico between 2010 and 2022. Clinical, epidemiological, biochemical, molecular, and therapeutic variables were analyzed.

The median age at symptom onset was 3 years, whereas the median age at diagnosis was 7 years, showing an approximate four-year diagnostic delay. At initial evaluation, 87% of patients were still ambulatory. The most frequent clinical findings were calf pseudohypertrophy in 94.5% and Gowers’ sign in 87.8%. Serum creatine kinase levels ranged from 1,102 to 58,497 IU/L. Molecular testing showed deletions in 83% of genetically confirmed cases, with 74% involving the exon 45–55 mutational hotspot. Corticosteroid therapy was used in 81% of patients, mainly deflazacort. Neuropsychiatric, orthopedic, and respiratory comorbidities were documented in 41.9%, 44.5%, and 44.6% of cases, respectively. The mean age at loss of independent ambulation was 10.2 years. Only 6.7% of patients were eligible for mutation-specific therapies.

This 12-year Mexican cohort highlights that children with Duchenne muscular dystrophy continue to experience a substantial diagnostic delay despite recognizable clinical manifestations. Routine creatine kinase screening in boys with motor delay, abnormal gait, or unexplained hypertransaminasemia, followed by early molecular confirmation and multidisciplinary care, may improve outcomes and expand access to precision therapies in resource-limited healthcare systems.

Jorge Sánchez-Vargas is a Pediatric Neurologist and Clinical Neurophysiologist at the National Institute of Pediatrics, Mexico City. His clinical and research activities focus on pediatric neuromuscular disorders, pediatric epilepsy, electroencephalography, neurogenetics, and clinical neurophysiology. He is actively involved in the diagnosis and multidisciplinary management of children with rare neurological diseases, with particular interest in Duchenne muscular dystrophy, developmental and epileptic encephalopathies, and pediatric neurophysiology. He has authored peer-reviewed scientific publications in pediatric neurology and neuromuscular diseases, including clinical and epidemiological studies on Duchenne muscular dystrophy conducted at one of Mexico's largest pediatric referral centers. His research emphasizes early diagnosis, genotype-phenotype correlations, and the implementation of evidence-based multidisciplinary care to improve outcomes in children with neurological disorders. He is committed to advancing pediatric neurological research in Latin America through collaborative clinical studies and scientific dissemination at national and international conferences.