Introduction

Duchenne Muscular Dystrophy (DMD) is a progressive X-linked recessive disorder caused by mutations in the dystrophin gene. This leads to muscle weakness and eventual loss of mobility. Early diagnosis is essential for initiating treatment before significant muscle damage occurs. However, many DMD cases face diagnostic delays.

Case Report: Presymptomatic Diagnosis in an Infant

1. Clinical Presentation

• A four-month-old infant presented with elevated creatine kinase (CK) levels.
• No obvious symptoms of muscle weakness were observed.
• Routine tests were inconclusive, leading to further genetic analysis.

2. Genetic Testing and Findings

• Next-Generation Sequencing (NGS) identified a hemizygous deletion in exons 45–50 of the dystrophin gene.
• Chromosomal Microarray Analysis (CMA) detected a deletion in the Xp21.1 region.
• Findings confirmed the diagnosis of DMD before the onset of clinical symptoms.

Importance of Early Diagnosis

Early detection allowed the infant to:

• Enroll in a rehabilitation program to support motor function.
• Be evaluated for potential participation in clinical trials.
• Prepare for genetic treatments such as exon-skipping therapy.

Implications for Future DMD Diagnoses

This case highlights the importance of incorporating NGS and CMA into routine screening for infants with elevated CK levels. If implemented widely, these methods could:

• Reduce diagnostic delays and improve early intervention strategies.
• Enable genetic counseling for families with X-linked inheritance risks.
• Facilitate earlier treatment access to slow disease progression.

Conclusion

This case study demonstrates the effectiveness of Next-Generation Sequencing (NGS) and Chromosomal Microarray Analysis (CMA) in diagnosing DMD in presymptomatic infants. Early identification through advanced genetic testing can pave the way for timely interventions and improved clinical outcomes.