Genetics and Clinical Phenotypes of Epilepsy Associated with Chromosome 2q24.3 Microdeletion
Abstract number :
2.323
Submission category :
12. Genetics / 12A. Human Studies
Year :
2022
Submission ID :
2204103
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:23 AM
Authors :
Miaomiao Cheng, PhD – Peking University First Hospital; Na Zhao, MS – Cangzhou Central Hospital; Ying Yang, PhD – Peking University First Hospital; Xueyang Niu, PhD – Peking University First Hospital; Yi Chen, PhD – Peking University First Hospital; Xiaoling Yang, PhD – Peking University First Hospital; Yuehua Zhang, PhD – Peking University First Hospital
Rationale: To summarize the genetics and clinical phenotypes of epilepsy children with 2q24.3 microdeletion.
Methods: All the patients with 2q24.3 microdeletion were retrospectively collected at the Pediatric Department of Peking University First Hospital from March 2017 to March 2022, the features of clinical manifestations, electroencephalogram, and neuroimaging were analyzed.
Results: Eleven patients with 2q24.3 microdeletion were included. All eleven patients had de novo copy number variation (CNV) with a deletion size between 0.18Mb and 7.31 Mb. The main pathogenic genes in the region were SCN3A、SCN2A、TTC21B、SCN1A and SCN9A. Age at seizure onset ranged from 2 months to 8 months, and the median age was 3 months and 10 days. Multiple seizure types were observed, including focal seizures in 11 patients, GTCS in 5 patients, myoclonic seizures in 3 patients, epileptic spasm in 2 patients, and tonic seizures in 2 patients. Seizures were fever sensitivity in 8 patients. Status epilepticus was observed in 6 patients. One case had normal mental motor development and 10 cases (90.9%,10/11）had different degrees of developmental delay. Five patients had craniofacial abnormality, one had six-finger deformity of the right thumb, and one had multiple system abnormalities. EEG showed focal discharges in 2 cases, multifocal discharges in 4 cases, multifocal and generalized discharges in 1 case. Brain magnetic resonance imaging (MRI) showed enlargement of subarachnoid spaces in the frontal and temporal region in 4 patients, enlargement of lateral ventricle in 3 patients, delayed myelination of white matter in 1 patient. Dravet syndrome was diagnosed in 4 cases, and epilepsy of infancy with migrating focal seizures (EIMFS) in one case. The age at last follow-up were ranged from 1 year to 5 years and 6 months, 1 patient was seizure free for 1 year, and 10 patients still had seizures.
Conclusions: The main pathogenic genes in the deletion region of 2q24.3 microdeletion include SCN3A, SCN2A, TTC21B, SCN1A, and SCN9A. The seizure onset age of 2q24.3 microdeletion related epilepsy was in infancy. Multiple seizure types were observed, the common seizure types included focal seizures and GTCS. Most patients had fever sensitivity and status epilepticus. Seizures are refractory in most patients. More than 90% of patients had developmental delay. Some patients have abnormalities in other systems.
Funding: Key Research of the Ministry of Science and Technology of China (No. 2016YFC0904400 and 2016YFC0904401)
Genetics