Expanding phenotype of mitochondrial depletion syndrome in association with TWNK mutations

Mitochondrial DNA depletion syndromes (MDS) are a group of clinically and genetically heterogeneous autosomal recessive disorders characterized by a reduction of mtDNA. We report two siblings of Armenian origin with early onset neurodegenerative disease characterized by encephalopathy, severe hypotonia, facial dyskinetic movements, abnormal eye movements, severe failure to thrive, and abnormal renal and hepatic function. Sanger sequencing confirmed two variants in the C10orf2 gene (TWNK) and indicated a diagnosis of MDS. Our recent observation confirms that nephrocalcinosis and proximal tubulopathy can be a part of a clinical picture of MDS associated with TWNK mutations and document peculiar ocular and orobuccolingual dyskinesias. Wrist myoclonia and tongue tremor were new clinical features in our patients. We suggest that the above-mentioned clinical constellation could potentially provide the basis for the diagnosis of MDS.     

SLC35A2-related congenital disorder of glycosylation: Defining the phenotype

We aim to further delineate the phenotype associated with pathogenic variants in the SLC35A2 gene, and review all published literature to-date. This gene is located on the X chromosome and encodes a UDP-galactose transporter. Pathogenic variants in SLC35A2 cause a congenital disorder of glycosylation. The condition is rare, and less than twenty patients have been reported to-date. The phenotype is complex and has not been fully defined.Here, we present a series of five patients with de novo pathogenic variants in SLC35A2. The patients' phenotype includes developmental and epileptic encephalopathy with hypsarrhythmia, facial dysmorphism, severe intellectual disability, skeletal abnormalities, congenital cardiac disease and cortical visual impairment.Developmental and epileptic encephalopathy with hypsarrhythmia is present in most patients with SLC35A2 variants, and is drug-resistant in the majority of cases. Adrenocorticotropic hormone therapy may achieve partial or complete remission of seizures, but the effect is usually temporary. Isoelectric focusing of transferrins may be normal after infancy, therefore a congenital disorder of glycosylation should still be considered as a diagnosis in the presence of a suggestive phenotype. We also provide evidence that cortical visual impairment is part of the phenotypic spectrum.     

Neuroimaging and spectroscopy in children with epileptic encephalopathies

AIMS—To investigate the nature of the unifocal cortical abnormalities on FDG positron emission tomography (PET) in children with an epileptic encephalopathy but no focal abnormality on electroencephalogram or standard magnetic resonance imaging (MRI).METHODS—Repeat FDG PET, surface rendered high resolution MRI, and single voxel magnetic resonance proton spectroscopy of the areas of abnormal metabolism compared to the contralateral side in 11children aged 2 to 12 years. Imaging was repeated after a median of 13months.RESULTS—Visual analysis of repeat FDG PET revealed similar abnormalities in 10 of 11 children. Semiquantitative analysis revealed similar sited abnormalities in eight children. One child with ictal hypermetabolism initially had an inconsistent second scan. Magnetic resonance spectra in three children showed the N-acetylaspartate/choline ratio was lower in the hypometabolic focus than in the reciprocal area on the opposite side, in two children it was higher, and in one child it was equal. Surface rendered MRI was normal in seven of eight children, and showed temporal lobe asymmetry in one.CONCLUSION—In children with established epileptic encephalopathies most hypometabolic areas on FDG PET are stable over time. While focal neuronal loss is likely in these areas in some children, microdysplasias or other focal cortical dysplasias are probable in others.     

Landau-Kleffner 综合征的临床特征和远期预后

目的研究Landau-Kleffner综合征（LKS）的临床、脑电图特征、治疗反应和远期预后。方法对10例LKS患儿的临床及脑电图资料进行分析,并随访治疗效果及远期预后。结果起病年龄2～10、5岁。10例患儿均有获得性失语,表现为听觉失认。均有癫癎发作,8例有睡眠中部分运动性发作,其他发作形式还有不典型失神发作和全身强直一阵挛发作。9例伴有精神行为异常。10例均无听力异常、神经影像学异常及家族史。10例均有脑电图异常,9例有颞区限局性棘慢波发放,8例进行录像脑电图（VEEG）监测,4例发现睡眠中癫疴性电持续状态。10例癫疴发作均可用抗癫疴药物控制。经皮质激素治疗,10例失语均有改善。随访8例,癫癎发作控制均良好,5例语言较正常差。6例随访VEEG,2例停用激素后再次出现睡眠中持续放电。结论LKS是一个以获得性失语和癫疴发作为主要临床表现的儿童时期癫癎脑病。失语表现为听觉失认,多伴有其他精神行为异常。EEG常见颞区的限局性放电,睡眠期常泛化全导,并可呈持续发放。抗癫疴药物可控制癫疴发作,但对失语疗效不佳。早期应用足量皮质激素治疗可明显改善失语情况。EEG及癫癎发作转归良好,但常遗留语言障碍。     

KCNT1基因变异致早发癫痫性脑病1例报告并文献复习

目的 探讨KCNT1基因变异所致早发癫痫性脑病的临床特点、诊断及治疗.方法 回顾分析1例确诊KCNT1基因变异相关早发癫痫性脑病患儿的临床资料,并复习相关文献.结果 患儿女,2岁7个月,自新生儿期起频繁癫痫发作,以局灶阵挛性发作为主要表现,伴发育落后.脑电图示痫样放电.头颅影像学及遗传代谢筛查无明显异常.基因检测结果患...     

Ohtahara syndrome or early-onset West syndrome? A case with overlapping features and favorable response to vigabatrin

BackgroundThe so called “severe neonatal epilepsies with suppression-burst pattern” include early infantile epileptic encephalopathy, and early myoclonic encephalopathy. Both syndromes are characterized by pharmacoresistant seizures that appear in the first weeks (up to the third month) of life, an electroencephalographic suppression-burst pattern, and a grim prognosis. Many patients later present with other forms of epileptic encephalopathies with difficult-to-treat seizures, such as West syndrome, and those who survive usually suffer from severe neurodevelopmental troubles. We here report the case of a patient who presented at our center with features consistent with a mixed form of these epileptic encephalopathies, and favorable neurodevelopmental evolution.AimsTo draw attention on the potentially favorable effect of vigabatrin in early-onset epileptic encephalopathies.MethodsCase study.ResultsIn our patient, seizures immediately stopped upon initiation of vigabatrin treatment, and his development and neurological examination at one year are normal.ConclusionsVigabatrin should be considered as an early treatment option in early-onset epileptic encephalopathies.     

癫癎发作生物节律的研究进展

随着对癫癎研究的不断深入,癫癎发作的时相性越来越受到关注。癫癎发作存在生物节律,同一类型的癫癎在不同时间段、不同状态(睡眠/觉醒、昼夜更替)发作频率不同。癫癎生物节律的分子机制、内分泌机制相当复杂,目前存在多种假说。明确癫癎发作的生物节律,根据其发作节律予以预防及治疗,既可以有效控制癫癎发作,也可以减少药物不良反应。癫癎发作生物节律的研究将为癫癎治疗提供新的思路。     

Clinical phenotype associated with variants in TANGO2: A case study

Transport and Golgi organization 2 (TANGO2) disease is a severe inherited disorder that presents with multiple symptoms and a broad spectrum of phenotypes, including metabolic crisis, encephalopathy, cardiac arrhythmia, and hypothyroidism. The clinical picture of a TANGO2 gene biallelic mutation involves encephalopathy and rhabdomyolysis and is marked by cardiac rhythm disorders and neurological regression. The presentation of encephalopathy varies and can range from isolated language delay and cognitive impairment to multiple disabilities and spastic quadriparesis. A TANGO2 gene mutation causes serious illness with a limited life expectancy due to the unpredictable risk of cardiac rhythm disorder and death, particularly during rhabdomyolysis. Clinicians must therefore consider the TANGO2 gene when confronted with rhabdomyolysis in a patient suffering from an early developmental disorder. Currently, managing this disease is purely symptomatic. Here, we report the clinical features of a 10-year-old girl with mutations in the TANGO2 gene. Unique to our case was the lack of elevated creatine kinase during the early acute crises of cardiac failure and multi-organ failure, as well as the lack of any prior mental retardation associated with the aberrant heart rhythm.     

Dravet syndrome: The main issues

Dravet syndrome (DS) is a severe form of infantile onset epilepsy characterized by multiple seizure types, prolonged convulsive seizures and frequent episodes of status epilepticus. Seizures precipitated by fever are a main characteristic. Affected children exhibit normal early development. Cognitive impairment, behavioral disturbances with hyperactivity and sometimes autistic traits occur after seizure onset. Seizures persist into adulthood but become less frequent. In about 85% of patients, a mutation of the SCN1A gene is present. DS fully illustrates the concept of epileptic encephalopathy. However, it is difficult to determine the causative role of the underlying sodium channel dysfunction and that of the consequent seizures in influencing cognitive outcome. An overwhelmingly high number of SCN1A mutations have been associated with DS. Intragenic or whole gene deletions, duplications and amplifications are additional rare molecular mechanisms. Most mutations are de novo, but familial mutations also occur. Somatic mosaic mutations should be considered when estimating the recurrence. MRI imaging is usually normal, and no neuropathologic signature of the condition seems to exist. In heterozygous Scn1a+/? mice, GABAergic interneurons exhibit substantially reduced sodium current density with reduced ability for sustained action potential firing. GABAergic output is reduced and excitability of downstream synaptic targets increased. Stiripentol was effective in combination with valproate and clobazam in two pivotal phase III trials. Phenytoin, carbamazepine, and lamotrigine can worsen seizures and should be avoided. Prospective studies will clarify to what extent earlier diagnosis and efforts at seizure control with the most appropriate drug combinations will reduce clinical deterioration.     

The phenotype caused by recessive variations in SLC25A22: Report of a new case and literature review

We describe the clinical, electroencephalography (EEG), and developmental features of a patient with developmental and epileptic encephalopathy due to a homozygous pathogenic variation of mitochondrial glutamate/H⁺ symporter SLC25A22. Epilepsy began during the first week of life with focal onset seizures. Interictal EEG revealed a suppression-burst pattern with extensive periods of non-activity. The prospective follow-up confirmed developmental encephalopathy as well as ongoing active epilepsy and almost no sign of development at 8 years of age. We confirm in the following paper that SLC25A22 recessive variations may cause a severe developmental and epileptic encephalopathy characterized by a suppression-burst pattern. On the basis of an in-depth literature review, we also provide an overview of this rare genetic cause of neonatal onset epilepsy.     

Electrical status epilepticus in sleep,a constitutive feature of Christianson syndrome?

Christianson syndrome (CS) is a X-linked neurodevelopmental disorder, including severe intellectual disability (ID), progressive microcephaly, ataxia, autistic behaviour (ASD), near absent speech, and epilepsy. Electrical status epilepticus in sleep (ESES) has been reported in two patients. We describe five male patients from three unrelated families with Christianson syndrome caused by a pathogenic nucleotide variation or a copy-number variation involving SLC9A6. ESES was present in three out of the five patients in the critical age window between 4 and 8 years. All patients presented with severe intellectual disability, autistic features, and hyperactivity. Epilepsy onset occurred within the first two years of life. Seizures were of various types. In the two boys with a 20-years follow-up, epilepsy was drug-resistant during childhood, and became less active in early adolescence. Psychomotor regression was noted in two patients presenting with ESES. It was difficult to assess to what extent ESES could have contributed to the pathophysiological process, leading to regression of the already very limited communication skills. The two published case reports and our observation suggests that ESES could be a constitutive feature of Christianson syndrome, as it has already been shown for other Mendelian epileptic disorders, such as GRIN2A and CNKSR2-related developmental epileptic encephalopathies. Sleep EEG should be performed in patients with Christianson syndrome between 4 and 8 years of age. ESES occurring in the context of ID, ASD and severe speech delay, could be helpful to make a diagnosis of CS.     

Neonatal neurobehavioral abnormalities and MRI brain injury in encephalopathic newborns treated with hypothermia

Background

Neonatal Encephalopathy (NE) is a prominent cause of infant mortality and neurodevelopmental disability. Hypothermia is an effective neuroprotective therapy for newborns with encephalopathy. Post-hypothermia functional–anatomical correlation between neonatal neurobehavioral abnormalities and brain injury findings on MRI in encephalopathic newborns has not been previously described.

Aim

To evaluate the relationship between neonatal neurobehavioral abnormalities and brain injury on magnetic resonance imaging (MRI) in encephalopathic newborns treated with therapeutic hypothermia.

Study design

Neonates with hypoxic ischemic encephalopathy (HIE) referred for therapeutic hypothermia were prospectively enrolled in this observational study. Neurobehavioral functioning was assessed with the NICU network neurobehavioral scale (NNNS) performed at target age 14 days. Brain injury was assessed by MRI at target age 7–10 days. NNNS scores were compared between infants with and without severe MRI injury.

Subjects & outcome measures

Sixty-eight term newborns (62% males) with moderate to severe encephalopathy underwent MRI at median 8 days (range 5–16) and NNNS at median 12 days of life (range 5–20). Fifteen (22%) had severe injury on MRI.

Results

Overall Total Motor Abnormality Score and individual summary scores for Non-optimal Reflexes and Asymmetry were higher, while Total NNNS Z-score across cognitive/behavioral domains was lower (reflecting poorer performance) in infants with severe MRI injury compared to those without (p < 0.05).

Conclusions

Neonatal neurobehavioral abnormalities identified by the NNNS are associated with MRI brain injury in encephalopathic newborns post-hypothermia. The NNNS can provide an early functional assessment of structural brain injury in newborns, which may guide rehabilitative therapies in infants after perinatal brain injury.     

反复抽搐、肺部感染并发育落后

患儿,女,4月龄,新生儿期出现抽搐,初起为局灶性运动发作,4月龄时转变为痉挛和强直-痉挛发作,并有发育落后及反复肺部感染。脑电图示高度失律,头颅磁共振、脑脊液检查正常,血氨、血乳酸、血液氨基酸和酰基肉碱谱分析、尿液有机酸分析正常,基因检测发现GNAO1 c.607G>A （p.G203R）新生杂合错义突变,确诊为GNAO1相关早发性癫癎脑病（EIEE17型）。改用托吡酯和氨己烯酸治疗,癫癎发作控制,但精神运动发育无进步,肺部感染反复,12月龄时因重症肺炎死亡。对于不明原因早发性癫癎脑病患儿需警惕GNAO1基因突变,尽早进行遗传学检测,并注意可能合并反复肺部感染。     

Punctate white matter lesions in full-term infants with neonatal seizures associated with SLC13A5 mutations

Introduction

Early-onset epileptic encephalopathy caused by biallelic SLC13A5 mutations is characterized by seizure onset in the first days of life, refractory epilepsy and developmental delay. Little detailed information about the brain MRI features is available in these patients.

A de novo GABRA2 missense mutation in severe early-onset epileptic encephalopathy with a choreiform movement disorder

Background

Early-onset epileptic encephalopathy (EOEE) is a severe convulsive disorder with a poor developmental prognosis. Although it has been associated with mutations in a number of genes, the fact that there is a large proportion of patients who remain undiagnosed suggests that there are many more still-unknown genetic causes of EOEE. Achieving a genetic diagnosis is important for understanding the biological basis of the disease, with its implications for treatment and family planning.

Coma associated with intense bursts of abnormal movements and long-lasting cognitive disturbances: an acute encephalopathy of obscure origin.

We report six previously healthy children who several days after a prodromal illness had an acute encephalopathy that ran a biphasic course. It appears to constitute a recognizable syndrome with a good prognosis that can be differentiated from other encephalopathies of obscure origin as previously defined by Lyon et al. The active phase was dominated by coma or confusion and by abnormal movements, including disordered gesticulation and attacks of orofacial dyskinesia or limb dystonia associated with permanent rigidity and culminating in opisthotonic posturing. Repeated seizures were observed in only two patients. Permanent slow waves were recorded on the electroencephalogram in all patients, even during bursts of abnormal movements. Cerebrospinal fluid and results of serologic studies were normal throughout the course of the disease, and attempts at viral isolation and antiviral antibody detection yielded negative results. Brain imaging either showed no abnormalities or suggested a moderate degree of brain edema. The recovery phase, which extended for several weeks, was characterized by a rapid return of motor function and persistent behavioral and cognitive disturbances. Nonverbal reasoning recovered long before verbal expression returned to normal. Four patients eventually recovered fully, whereas two had mild sequelae.     

STXBP1基因突变致癫性脑病8例病例系列报告

目的 总结STXBP1基因突变所致的癫性脑病的临床表现及基因突变特点。方法 回顾性分析2011年12月30日至2018年1月31日于复旦大学附属儿科医院就诊且基因诊断为STXBP1基因突变的癫性脑病患儿的临床特点、基因检测结果、治疗和疗效。结果 8例STXBP1基因突变致癫性脑病患儿进入本文分析,男、女各4例,起病年龄为生后2 d至6月龄（中位数为生后15 d）。8例均存在发育落后,均有不同程度的反应欠佳、眼示踪较差,2例角弓反张,1例皮肤黝黑、阴囊着色较深。脑电图波形：4例为暴发抑制,3例为高峰失律,1例为两侧较多痫样放电。2例行DST（智力及发育筛查）,DQ（发育商）和MI（智商指数）均<50。1例合并先天性喉软骨发育不良,腹部B超示肾上腺皮质均质性增大。1例合并孤独症。8例共检测到7个STXBP1基因突变位点,其中错义突变4个,无义突变2个,移码突变1个。c.1216C>T (p.R406C)、c.246G>A（p.K82K）、c.1702G>A(p.G568S)和 c.54delG位点此前未被人类基因突变数据库(HGMD)收录,经软件预测均为有害突变;c.1439C>T（p.P480L）、c.585 C>G( p.Y195X)和c.1162C>T（p.R388X）为HGMD已收录的致病位点。4例诊断为大田原综合征,3例为WEST综合征,1例为不能分类的癫综合征。经过单药或联合治疗,5例得到临床发作控制,3例表现为药物难治性癫。结论 STXBP1基因突变相关的癫性脑病是严重的儿童神经系统疾病,肾上腺增大可能为其新的表型之一。     

Late onset epileptic spasms is frequent in MECP2 gene duplication: Electroclinical features and long-term follow-up of 8 epilepsy patients

Mutation of the X-linked methyl CpG binding protein 2 (MECP2) has been first identified as the cause of Rett syndrome. More recently, MECP2 gene duplication syndrome has been identified in males. The MECP2 duplication syndrome is characterized by severe mental retardation, infantile hypotonia, progressive spasticity and recurrent infections. Epileptic seizures are inconstant but poorly described. The aim of the study is to describe the electroclinical features of epilepsy in MECP2 duplication patients in order to refine the epilepsy phenotype and its evolution.MethodsWe conducted a retrospective study in four child neurology departments in France. Eight boys with a MECP2 gene duplication and epilepsy were retrospectively studied. We evaluated both clinical and electroencephalographic data before seizure onset, at seizure onset and during the follow-up.ResultsThe patients started seizures at the median age of 6 years (range: 2.5–17 years). Half exhibits late onset epileptic spasms while the other exhibit either focal epilepsy or unclassified generalized epilepsy. Before seizure onset, EEGs were abnormal in all patients showing a slowing of the background or a normal background with fast activities, while EEG performed in epileptic patients, showed a slowing of the background in 6/8 and localized slow or sharp waves in 7/8. Most patients (6/8) have evolved to drug resistant epilepsy.ConclusionAlthough late onset epileptic spasms are common in patients with MECP2 duplication, no specific electroclinical phenotype emerges, probably due to genetic heterogeneity of the syndrome. Further studies are needed to individualize specific epileptic subtype in larger cohort of patients.     

GABRA1基因变异相关癫痫的临床表型特点

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.