Objective: We aim to analyze phenotypical features of individuals from eastern Algeria having a PME phenotype followed in our center (Dr Benbadis University Hospital).

Background: Progressive myoclonic epilepsies (PME) are a heterogeneous group of rare hereditary disorders mainly autosomal recessive. PMEs are defined by the presence of myoclonus, epilepsy, ataxia and cognitive decline that progress gradually. Besides typical PMEs, other neurological and metabolic affections can mimic PMEs and have additional atypical features.

No study has explored PMEs prevalence in the Algerian population yet.

Method: We performed a transversal retrospective study on 14 probands from 11 families (Fig. 01) with a PME phenotype recruited between December 2023 and December 2024 in our epilepsy outpatients clinic.  Prevalence was calculated from family data of other affected members (33 patients).

Results: The prevalence was 4/1000000 with a Sex ratio of 1.8. 71.4% of cases had familial history and 64.3% were born from consanguineous marriage. Mean age was 21.9 years (7-45 years old). Mean age of onset was 9.1 years old and 78.6% had onset between 5-15 years old. Generalized tonic clonic seizures were the sign of onset in 40% of cases, 20% reported myoclonus and 20% reported ataxia as the first symptom appearing. From the 14 probands, seven had an Unverricht Lundborg (ULD) phenotype, two had Lafora-like (LD) phenotype and one was confirmed by biopsy pathology and five had Neuronal ceroid lipofuscinosis (CLN) phenotype (Fig. 02).

Conclusion: PMEs are suspected following typical presentation, genetic confirmation is needed to identify disease subtypes. Treatment remains symptomatic and gene therapy is offering hope for the future.

Fig 02. Probands phenotypes

Fig 01. Pedigrees of included patients

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/phenotypical-study-of-progressive-myoclonic-epilepsy-in-eastern-algeria/