[Clinical phenotypes of epilepsy associated with GABRA1 gene variants]

Zhonghua Er Ke Za Zhi. 2020 Feb 2;58(2):118-122. doi: 10.3760/cma.j.issn.0578-1310.2020.02.010.
[Article in Chinese]

Abstract

Objective: To summarize the clinical phenotypes of epilepsy in patients with GABRA1 gene variants. Methods: A total of 11 epileptic patients (4 boys and 7 girls) who were treated in the Department of Pediatrics, Peking University First Hospital from March 2016 to July 2019 and detected with GABRA1 gene heterozygous pathogenic variants by targeted next-generation sequencing were enrolled. The features of clinical manifestations, electroencephalogram (EEG), and neuroimaging were analyzed retrospectively. Results: A total of 11 epileptic patients carried GABRA1 gene pathogenic variants, of whom 10 were de novo variants and the other one was inherited from the patient's mother. Two patients had the same variants. Six variants were novel. Ages at seizure onset ranged from 3 to 14 months, and the median age was 8 months. The seizure was first observed within 1 year in 10 patients and beyond 1 year of age in 1 patient. Multiple seizure types were observed, including focal seizures in 10 patients, generalized tonic clonic seizures (GTCS) in 3 patients, myoclonic seizures in 3 patients, and epileptic spasm in 2 patients. There were 5 patients with multiple seizure types. Sensitivity to fever was observed in 9 patients, among whom 6 patients had a history of status epilepticus. Two patients had photoparoxysmal response. Five patients had abnormal EEG background, and 6 patients had abnormal discharges in EEG during interictal phase. Brain magnetic resonance imaging (MRI) was normal in all patients. Developmental delay in various degrees was present in 9 patients. Among the 11 patients, Dravet syndrome was diagnosed in 5 patients, West syndrome in 2 patients, undiagnosed early-onset epileptic encephalopathy in 1 patient, and focal epilepsy in the other 3 patients. The ages at the last follow-up ranged from 8 months to 12 years. During follow-up, 8 patients were seizure-free for 6 months to 8 years, and 1 patient had discontinuation of medication. Conclusions: In epilepsy associated with GABRA1 gene variants, de novo pathogenic variants are more common than inherited. Most epilepsy caused by GABRA1 gene variants occurs in infancy. Most patients have multiple seizures and focal seizures are common. Most patients have a comparatively favorable prognosis, but they may still have varied degrees of developmental delay.

目的: 探讨GABRA1基因变异相关癫痫患儿的临床表型特点。 方法: 收集2016年3月至2019年7月在北京大学第一医院儿科就诊的癫痫患儿,并通过靶向捕获二代测序发现GABRA1基因变异的11例患儿(男4例、女7例),回顾性总结其临床表现、脑电图及头颅影像学特点。 结果: 11例患儿中,10例为新生变异,1例为遗传性变异。2例患儿携带相同的变异,6例患儿携带国际未报道的新变异。癫痫起病年龄8(3~14)月龄,其中1岁内起病10例,1岁后起病1例。癫痫发作类型多样,其中局灶性发作10例,全面性强直-阵挛发作3例,肌阵挛发作3例,痉挛发作2例。有5例患儿具有多种发作类型。9例发作有热敏感特点,其中6例因发热诱发癫痫持续状态。2例具有光敏感特点。11例患儿脑电图显示背景异常5例,发作间期有异常放电6例。所有患儿的头颅磁共振成像均未见明显异常。9例患儿有不同程度的发育落后。临床诊断为Dravet综合征5例,婴儿痉挛症2例,不能分类的早发癫痫性脑病1例,其余3例为局灶性癫痫。11例患儿末次随访年龄为8月龄~12岁,8例癫痫发作已缓解6个月~8年,其中1例已停用抗癫痫药物。 结论: GABRA1基因变异中新生变异较遗传变异常见,其导致的癫痫多数在婴儿期起病,癫痫发作类型多样,局灶性发作最为常见。多数患儿发作预后好,但普遍发育落后。.

Keywords: Developmental delay; Epilepsy; Genes, GABRA1; Seizures.

MeSH terms

  • Brain / diagnostic imaging*
  • Child
  • Child, Preschool
  • Developmental Disabilities / etiology
  • Developmental Disabilities / genetics*
  • Electroencephalography
  • Epilepsy / diagnosis*
  • Epilepsy / diagnostic imaging
  • Epilepsy / genetics*
  • Female
  • Humans
  • Infant
  • Male
  • Neuroimaging
  • Phenotype
  • Receptors, GABA-A
  • Retrospective Studies
  • Seizures / etiology*
  • Spasms, Infantile / diagnosis

Substances

  • GABRA1 protein, human
  • Receptors, GABA-A