Parietal Lobe Epilepsy Associated With 2q13 Duplication: Expanding the Neurogenetic Spectrum

Copy number variations (CNVs) involving the 2q13 region have been associated with a wide range of phenotypes, including developmental delay, dysmorphic features, hypotonia, and congenital heart defects. However, parietal lobe epilepsy has not yet been reported in association with 2q13 duplication. We describe the case of a 20-year-old woman with a duplication of the 2q13 region identified during childhood, who later presented with recurrent, brief episodes of right upper limb paresthesia spreading to other limbs, followed by transient pain. Her past medical history included dyspraxia, polycystic ovary syndrome, atrial fibrillation, and intellectual disability. Electroencephalography (EEG) revealed interictal epileptiform discharges, consisting of paroxysmal sharp theta waves in the left parietal and temporal regions, spreading to adjacent and contralateral areas, particularly during hyperventilation. Based on clinical and EEG features, a diagnosis of parietal lobe epilepsy was established. Treatment with levetiracetam resulted in significant clinical improvement, characterized by complete resolution of the previously described episodes of recurrent, brief right upper limb paresthesia spreading to other limbs, followed by transient pain, as well as a reduction of epileptiform abnormalities on EEG. The duplicated region includes several genes involved in neuronal development, synaptic regulation, and myelination, such as MERTK, TMEM87B, and FBLN7. Their altered expression may contribute to cortical excitability and epileptogenesis. This case adds to the phenotypic variability reported in individuals with 2q13 duplication and underscores the importance of further studies to explore possible gene-specific contributions to neurological findings. This is the first report linking 2q13 duplication with parietal epilepsy, underlining the importance of considering CNVs in unexplained focal epilepsy presentations.