Sporadic progressive myoclonic epilepsy with early‐onset dementia caused by a de novo mutation in PSEN1

Abstract

AbstractProgressive myoclonic epilepsy contains wide variety of diseases in which differential diagnosis is challenging. Here, we report a 36 year‐old female patient presenting with sporadic myoclonic epilepsy and cognitive decline. Cerebrospinal fluid analysis revealed increased level of total tau and phosphorylated tau and decreased level of amyloid beta‐42 protein, although the extent was modest. Whole‐exome sequencing analysis revealed a known heterozygous de novo mutation p.Phe177Ser in PSEN1, a causative gene for familial Alzheimer's disease. A previously reported pedigree with the same mutation presented with similar phenotypes, indicating genotype‐phenotype correlation. This report illustrated that familial Alzheimer's disease with PSEN1 mutations should be considered in the differential diagnosis of progressive myoclonus epilepsy.