Epilepsy and Duchenne muscular dystrophy: prevalence and genetic characteristics in a tertiary hospital sample

*Correspondence: [e-mail].

Abstract

Background: Epilepsy in patients with Duchenne muscular dystrophy (DMD) was previously described as a rare entity. However, new studies suggest that such an association is more common than previously thought, with the prevalence of epilepsy in patients with DMD being 3.14 to 8%, higher than the general population (0.5 to 1%).

Objective: To assess the prevalence of epilepsy in patients with DMD, in addition to its characteristics and relationship with the type of genetic mutation.

Methods: A retrospective study based on the analysis of medical records of DMD patients from an outpatient clinic at a tertiary hospital in São Paulo, Brazil. The following data were collected: age, type of genetic mutation, presence and type of epilepsy, characteristics of the electroencephalogram (EEG), amount of anti-epileptic drugs in use and presence of neurodevelopmental disorders.

Results: A sample of 144 DMD patients was evaluated, 4 (2.8%) had epilepsy and the mean age was 12.6 years. Among the patients with epilepsy, one had focal seizures with EEG findings of multifocal epileptiform paroxysms and frameshift mutation in exon 56 of the DMD gene. Another patient had generalized seizures and EEG with generalized poly-spike wave discharges and frameshift mutation in exon 59 of the DMD gene. One patient had no record of seizure type or EEG characteristics, with a frameshift mutation in exon 2 of the DMD gene. The last patient developed refractory epilepsy with encephalopathy, had focal seizures with EEG findings of multifocal epileptiform paroxysms and two clinical-electrographic seizures characterized by rapid right frontotemporal projection activity. Genetic analysis showed deletion of exons 46 to 48 of the DMD gene. Given the presence of encephalopathy, an exome analysis was performed, with the finding of a heterozygous mutation in the GABRG2 gene (associated with epileptic encephalopathy).

Conclusion: The sample of DMD patients showed a higher prevalence of epilepsy when compared to the general population. The genetic analysis showed mostly mutations downstream of exon 45 of the DMD gene, a region related to the Dp140− isoform, expressed in the CNS and possibly related to the pathophysiology of epilepsy in these patients. One of the patients with epilepsy also had a mutation in the GABRG2 gene, showing the importance of extending the diagnostic workup in cases of refractory epilepsy. Therefore, further studies are needed to understand the relationship between DMD and epilepsy.

Publication History

Article published online:
12 May 2025