Clinical characteristics and gene analysis of SMC1A gene related disorders / 中华神经科杂志

Objective:To analyze the clinical characteristics and genetic features of SMC1A gene related disorders. Methods:The data of 5 children with SMC1A gene variants were collected from Children′s Hospital of Fudan University from February 2018 to January 2022. The clinical features, electroencephalogram (EEG), brain imaging and gene testing results were summarized. Results:Among the 5 patients, 4 are females and 1 is male. Two female cases are siblings. One boy had dysmorphic features, consisting of bilateral ptosis, synophrys, a short nose and upturned nasal tip. He also had patent foramen ovale plus atrial septal defect, unilateral cryptorchidism and microcephaly. Three cases had microcephaly. Two girls had patent foramen ovale, and 2 girls had microcephaly. Four cases had epilepsy, and age at seizure onset ranged from 2 to 52 months. Multiple seizure types were observed, including bilateral tonic clonic seizures in 2 patients, and focal seizures in 3 patients. The seizures in 3 cases were in cluster. All patients had developmental delay, including 1 patient with mild and 4 patients with moderate to severe developmental delay. Three patients had slow background activity in EEG. Interictal EEG showed abnormal discharges in 4 patients, including focal discharges in 3 cases and generalized discharges in 1 case. Brain magnetic resonance imaging was normal in 3 patients and showed mild cortical thickening in 1 case. All cases harbored 4 SMC1A gene variants, including 2 missense variants and 2 frameshift variants (c.580_587del, c.2699delG, c.3362G>A, c.1486C>T). Three cases harbored heterozygous SMC1A variants and 2 cases carried somatic mosaic SMC1A variants with 17.5% and 88.1% mosaicism in peripheral blood. The follow-up lasted for 3 months to 4 years. The epilepsy was refractory in 2 cases. During the follow-up, all cases had very slow developmental progress or developmental retardation. All cases had different levels of growth retardation. The scores of Cornelia de Lange syndrome (CdLS) phenotypes in 5 cases were 2-6. One case had the combined phenotypes of atypical CdLS and developmental epileptic encephalopathy (DEE). The phenotype was atypical CdLS in 1 case and DEE in 1 case. The phenotypes of 2 cases with SMC1A missense variants were mild, manifesting as non-refractory epilepsy and moderate to severe developmental delay. Conclusions:All of cases with SMC1A gene variants have developmental delay. Most of the patients have clusters of seizures and some dysmorphisms. The phenotypes of SMC1A gene related disorders are diverse. Except CdLS and DEE, there are some patients with mild phenotype due to missense variants of SMC1A gene.

A case of developmental epileptic encephalopathy type 67 caused by CUX2 gene mutation and literature review / 中华神经科杂志

Objective:To summarize the clinical phenotype and CUX2 gene variation characteristics of developmental epileptic encephalopathy type 67 confirmed by whole exome sequencing. Methods:Clinical data of 1 case diagnosed as CUX2 gene mutations related developmental epileptic encephalopathy type 67 in the Children′s Hospital Affiliated to Zhengzhou University in January 2021 were collected, the patient′s clinical characteristics, genetic testing, head imaging, electroencephalogram results and treatment were summarized, and the patient was regularly followed-up every 3 months. At the same time, the domestic and foreign literatures on epileptic encephalopathy caused by CUX2 gene mutation were reviewed. Results:The proband was a 6 years and 4 months old girl. The main clinical manifestations included focal origin progression to bilateral tonic-clonic seizures, retardation of intellectual, language, and motor development, autistic behavior, hyperactivity disorder, and involuntary hand clapping. The video electroencephalogram showed extensive spiny slow wave and multi-spiny slow wave emission in waking and sleeping stages, and spiny slow wave and spiky slow wave emission in bilateral anterior head in sleeping stage. Brain magnetic resonance imaging (MRI) plain scan and T 2-fluid attenuated inversion recovery (T 2-FLAIR) thin layer scan showed that the signal of the left hippocampus was higher than that of the right, and the left hippocampus was slightly swollen. One month later, the brain MRI and T 2-FLAIR were reexamined. The left hippocampal signal was still slightly higher and decreased, and the hippocampal volume was slightly reduced. Whole exome sequencing showed the CUX2 gene with c.1768G>A(p.Glu590Lys) heterozygous missense variant, which was a reported de novo pathogenic variant and both of her parents were wild-type. A total of 10 cases of new heterozygous missense variants in CUX2 gene [c.1768G>A (p.Gelu590Lys)] were reported in 4 literatures. No relevant cases have been reported in China. Conclusions:Developmental epileptic encephalopathy type 67 is relatively rare. The main clinical features are seizures, global developmental delay, movement disorders, athetosis, autism and hyperactivity disorder. The heterozygous missense variant c.1768G>A (Glu590Lys) of CUX2 gene maybe the genetic cause of this case.

Developmental epileptic encephalopathy associated with the CACNA1E gene mutation / 中华实用儿科临床杂志

One of the important causes of developmental epileptic encephalopathy (DEE) is the mutation of ion channel genes, including the mutation of the CACNA1E gene. CACNA1E-related DEE cases were first reported in 2018.The mutation types include new missense mutations, nonsense mutations and frameshift mutations, but the correlation between mutation sites and types with the phenotype of DEE is not clear.This review aims to summarize the reported CACNA1E-related DEE cases, and explore the correlation between the clinical phenotype of CACNA1E-related DEE and gene mutation sites and mutation types.Meanwhile, possible pathogenesis of CACNA1E-related DEE and the progress of drug intervention were reviewed to provide references for the diagnosis and precise treatment of DEE.

Genotype and phynotype of DNM1 gene variants related developmental epileptic encephalopathy / 中华实用儿科临床杂志

Objective:To summarize the clinical features of developmental epileptic encephalopathy children with DNM1 gene variants. Methods:The genotypes and clinical features of 15 children with DNM1 variants related epilepsy in the Department of Pediatrics, Peking University First Hospital from June 2017 to October 2021 were retrospectively analyzed. Results:A total of 8 male and 7 female epilepsy patients with DNM1 gene variants with the age of seizure onset ranging from 15 days to 22 months were recruited, median age was 8 months.All cases belonged to de novo heterozygous variants of the DNM1 gene, including 13 cases of missense variants, 1 case of frame shift variant and 1 case of nonsense variant, 8 cases of ectopic sites have not been reported.Multiple seizure types were observed, including epileptic spasms in 15 patients, focal seizure in 9 patients, atypical absence seizure in 2 patients and tonic seizure in 2 patients.There were various types of seizures in 7 children.Nine cases occurred as infantile spasm for the first time.All 15 patients showed varied degrees of development delay, among them, 11 cases had developmental retardation before epilepsy.Three patients had slow rhythm of electroencephalogram background activity, the electroencephalography showed hypsarrhythmia in 13 patients; clinical seizures were detected in 8 cases, among them, epileptic spasms were captured in 7 patients, tonic seizure was captured in 1 patient.Widened frontotemporal subarachnoid space, cerebral atrophy, and corpus callosum dysplasia were examined in 6, 2 and 3 patients by cranial magnetic resonance imaging, respectively.All 15 cases were diagnosed as developmental epileptic encephalopathy, of which 13 cases were consistent with infantile spasms.The age of the last follow-up ranged from 1 year old to 7 years old.After multi-antiepileptic drug treatment, 2 patients were remission, 1 patient(small size of identical twins) died of severe pneumonia at the age of 2 years, and 12 patients still had intermittent seizures, of which 1 patient was transformed from infantile spasms to Lennox-Gastaut syndrome. Conclusions:The onset age of developmental epileptic encephalopathy caused by the DNM1 gene variant usually begins in the infantile period, the peak onset age was 8 months.The main types of seizures include epileptic spasms and focal seizures, developmental retardation can occur before seizures.The clinical manifestations are mostly infantile spasms syndrome, and some children can be transformed into Lennox-Gastaut syndrome.

Case report of developmental epileptic encephalopathy caused by UBA5 gene mutation and literature review / 中华实用儿科临床杂志

Objective:To summarize the clinical and gene mutation characteristics of a child with developmental epileptic encephalopathy (DEE) caused by ubiquitin-like modifier-activating enzyme 5( UBA5 )gene mutation, and to perform literature review. Methods:Clinical characteristics and genetic test results of a case of DEE treated in Department of Neurology, Xuzhou Children′s Hospital, Xuzhou Medical University, in March 2020 were retrospectively analyzed.Relevant literatures reporting DEE cases caused by UBA5 gene mutations published before June 2020 were searched in the PubMed, CNKI, Wanfang and other online databases with the following key words: epilepsy encephalopathy, developmental encephalopathy, epileptic encephalopathy, Developmental encephalopathy and UBA5. Results:A female case with 7 months and 23 days old presented epileptic spasms at 4 months of age, and the condition was uncontrolled by medication of adrenocorticotropic hormone (ACTH) and several antiepileptic drugs.The patient later progressed to recurrent, treatment-resistant seizures with arrested development, short stature, microcephaly, expressionless face, irritability, unsteady head, lack of follow-up vision, lack of laughing, and limb hypotonia.Whole exome sequencing revealed a missense mutation and a microdeletion in the UBA5 gene, and the missense mutation was paternal c. 722A>C (p.E241A), located in the 8 th exon region.The microdeletion deletion was maternally derived from the 5 th to 11 th exon, which constituted a compound heterozygous mutation.A total of 5 foreign literatures involving 18 children with DEE and 0 domestic literatures were retrieved.Combined with the present case, all 19 cases presented refractory seizures in the early infancy, and most of them were epileptic spasms (63.2%, 12/19 cases), followed by myoclonus (31.6%, 6/19 cases). The birth history of all children was unremarkable, and they later presented developmental disabilities at varying degrees, mainly including microcephaly (94.7%, 18/19 cases), lack of follow-up vision (89.5%, 17/19 cases), and short stature (94.7%, 18/19 cases), intellectual disabilities (89.5%, 17/19 cases), movement disorders (84.2%, 16/19 cases) and hypotonia (100.0%), 13/19 cases (68.4%) died.EEG results mainly revealed normal or hypsarrhythmia, but 1 case presented suppression- burst.Brain magnetic resonance imaging (MRI) findings mainly included delayed myelination (47.4%, 9/19 cases), brain atrophy (52.6%, 10/19 cases), and thin corpus callosum (26.3%, 5/19 cases). Conclusions:Children with UBA5 gene mutations often have refractory seizures in the early infancy, which are mainly epileptic spasms.They also show severe psychomotor developmental delay, microcephaly and dystonia, with an extremely poor prognosis.Brain MRI suggested varying degrees of myelin dysplasia, brain trophy, and thin corpus callosum.For cases with the above clinical manifestations, genetic testing should be considered to confirm the diagnosis.