This is a report on 11 cases of Juvenile Myoclonic Epilepsy (JME) from the University Hospital, Kuala Lumpur, all of whom were diagnosed in the last one and a half years. This genetic syndrome is seen in all the three main racial groups: Chinese, Malays and Indians. It accounts for 2% of the epilepsy patients seen at the neurology clinic. Lack of awareness is the main hindrance to diagnosis.
Study site: Neurology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
It is difficult to give a country report from Malaysia. A study done in 1999 reported the incidence of West Syndrome to be 3% among newly diagnosed cases of epilepsy. In this 3 year retrospective hospital-based study (1997-1999), the prevalence of early epileptic encephalopathy (EEE) and West Syndrome were 4.1 and 2.5% respectively. There is difficulty classifying EEE cases into distinct sub-groups of EIEE (early infantile epileptic encephalopathy), WS (West Syndrome) and SMEI (severe myoclonic epilepsy of infancy), using a combination of clinical features, EEG and CT/MRI findings.
Background & Objective: SCN1A gene which encodes for sodium channel alpha 1 subunit has been
found to be the most common mutated gene in patients with epilepsy. This study aims to characterize the
SCN1A mutations as well as to describe genotype and phenotype association in children with SCN1Arelated
infantile-onset epileptic encephalopathies in Malaysia.
Methods: Children with infantile-onset
epileptic encephalopathy mostly suspected to have Dravet syndrome who had mutational analysis for
SCN1A gene from hospitals all over Malaysia were included in the study. Their epilepsy syndrome
diagnosis was classified into severe myoclonic epilepsy in infancy and its variants. Polymerase chain
reaction and bidirectional sequencing were used to identify SCN1A mutations.
Results: A total of 38
children with heterozygous mutations were analysed, 22 (57.9%) of which were novel mutations.
Truncated mutations were the most common mutation type (19, 50%). Other mutation types were
missense mutations (14, 36.8%), splice site mutations (4, 10.5%) and in-frame deletion (1, 2.6%). The
mean age of seizure onset was 4.7 months. Seizure following vaccination was observed in 26.3% of
the children. All of them had drug resistant epilepsy. There was no significant association between
the type of mutation with the syndromic diagnosis, age of seizure onset, tendency of the seizures to
cluster or having status epilepticus, mean age when developmental delay was observed and response
to various antiepileptic drugs.
Conclusion: This study expands the spectrum of SCN1A mutations and proves the importance of
SCN1A gene testing in diagnosing infantile-onset epileptic encephalopathies patients. Although, our
study does not support any clinically meaningful genotype-phenotype association for SCN1A-related
infantile-onset epileptic encephalopathies, the clinical characteristics of our cohort are similar to those
that have been described in previous studies.
Juvenile myoclonic epilepsy (JME) is a common idiopathic generalised epilepsy with variable seizure prognosis and sex differences in disease presentation. Here, we investigate the combined epidemiology of sex, seizure types and precipitants, and their influence on prognosis in JME, through cross-sectional data collected by The Biology of Juvenile Myoclonic Epilepsy (BIOJUME) consortium. 765 individuals met strict inclusion criteria for JME (female:male, 1.8:1). 59% of females and 50% of males reported triggered seizures, and in females only, this was associated with experiencing absence seizures (OR = 2.0, p