Benign familial familial myoclonic epilepsy is an inherited form of epilepsy. Unlike other forms, it causes neither early dementia nor cerebellar ataxia. However, it manifests itself with cortical tremors in the hands and occasional seizures.

The first symptoms appear between 11 and 50 years of life; in most cases, it occurs for 20 years. At the beginning there is a short tremor in the hands, characterized by contractions that worsen in stressful conditions. As the person ages, the tremors become more severe. In rare cases, tonic-clonic seizures also occur, concentrated mainly around the age of 30. Again, stress exacerbates the symptoms. Familial myoclonic epilepsy is autosomal dominant.

The researchers identified four possible chromosomal loci that could be related to its appearance. The different loci appear to be linked to the patient's ethnic group and would also influence the symptoms. For now, the diagnosis is mainly based on clinical and electrophysiological analyzes: the electroencephalogram is used to identify anomalies in the traces.

Despite efforts, providing an accurate diagnosis is often difficult. Most sick people receive the wrong diagnosis of progressive myoclonic epilepsy, which instead leads to dementia and ataxia. Genetic counseling is possible if a family member has already received a diagnosis. To date there is no definitive treatment: beta-blockers are not very effective, while antiepileptics give some benefit. On the other hand, life expectancy remains unchanged.

Source: orpha.net