Dravet综合征的临床特点分析及SCN1A基因新突变

目的 分析Dravet综合征的临床特点,并对新诊断患儿进行SCN1A基因筛查,寻找基因突变.方法收集3例Dravet综合征患儿临床资料,留取例1患儿血样标本,提取外周血白细胞基因组DNA,对SCN1A全部外显子进行PCR扩增,通过变性高效液相色谱法对PCR产物进行突变片段筛查,对于变性高效液相色谱法筛查有异常的片段利用双脱氧法进行基因测序.利用基因序列分析软件进行测序结果分析.结果 1.Dravet综合征3例患儿的共同表现:均在1岁内起病;初以热性惊厥起病,1岁后逐渐转变为无热惊厥;发作形式包括肌阵挛、阵挛、不典型失神发作等;对药物治疗反应差,随病程进展出现精神运动发育迟缓或倒退;发作间歇期EEG可见尖慢波、棘慢波、多棘慢波发放或伴阵发.2.基因筛查结果发现SCN1A基因新突变c.2867T>G,可导致所编码氨基酸改变(M956R),经检索(截至2010年11月)尚未见该位点突变报道.结论 Dravet综合征是以热性惊厥起病但预后差的癫(癎)性脑病,临床应注意与热性惊厥鉴别.Dravet综合征患儿发病与SCN1A基因突变有相关性.     

HCN1基因变异致婴儿期癫痫1例并文献复习

目的 探讨HCN1基因变异相关癫痫临床表型及遗传学特点。方法 对2019-03-31就诊于重庆医科大学附属儿童医院的1例HCN1基因变异的癫痫患儿的临床资料进行分析。以“HCN1”“癫痫”“惊厥”“epilepsy”“seizure”为关键词,在Pubmed数据库、中国期刊全文数据库(CNKI)、万方数据知识服务平台中检索建库至2021年4月的国内外文献。总结HCN1基因变异相关癫痫的临床表型及基因型特点。结果 患儿女,入院时6月龄12 d。病初以热性惊厥持续状态起病,主要表现为全面性强直-阵挛发作,病程中逐渐出现局灶性发作,易表现为癫痫持续状态,存在热敏感性,丙戊酸钠联合左乙拉西坦抗癫痫发作治疗效果欠佳,1岁后逐渐出现生长发育落后。全外显子测序发现该患儿存在HCN1基因新发杂合错义变异(c.1199T>C/p.Leu400Pro),为既往未见报道突变。文献检索共收集到4篇英文文献,包括40例患者,其中散发病例26例,家系4个,包括本例共41例患者纳入分析,涉及25个变异位点,均为错义变异。患者癫痫发作形式多样,大多具有2种及以上发作形式,其中大部分患者存在全面性发作,半数以上存...     

高胰岛素血症伴高氨血症综合征1例报告并文献复习

目的探讨GLUD1基因变异所致高胰岛素血症伴高氨血症综合征临床表现和致病基因特点。方法回顾分析1例高胰岛素血症伴高氨血症综合征患儿的临床资料,并复习相关文献。结果女性患儿,1岁9个月起病,反复出现血糖偏低2年余,并惊厥发作3次,给予升血糖、止惊对症处理后可缓解;伴血胰岛素、血氨水平升高,诊断为高胰岛素血症伴高氨血症综合征。高通量测序发现患儿GLUD1基因存在错义变异c.965GA,p.Arg322His(杂合),其父母该位点均为正常基因型,为新生突变。结论基因检测有助于明确高胰岛素血症伴高氨血症综合征诊断。     

SCN1A基因突变致遗传性异卵双生Dravet综合征家系分析并文献复习

目的总结遗传性异卵双生Dravet综合征家系临床及SCN1A基因突变特点。方法分析华中科技大学同济医学院附属同济医院2017年6月收治的异卵双生Dravet综合征患儿兄妹各1例和全身性热性惊厥附加症(GEFS+)母亲家系的临床特征,进行SCN1A基因测序。并结合文献分析基因突变类型与Dravet综合征的关系。结果 2例患儿及其母亲均携带未报道过的SCN1A基因突变c.3624AT(p.R1208S),该突变位于蛋白的罕见区域(Na+通道α亚基第2个环)。SCN1A基因突变以点突变多见,约占93.8%,突变位置与Dravet综合征临床表型的相关性复杂。结论该病例为国内首次报道的遗传自双亲之一的异卵双生Dravet综合征。SCN1A基因突变c.3624AT(p.R1208S)发生于蛋白罕见区域,目前国际尚未报道。     

Dravet综合征研究进展

Dravet综合征是一种少见且严重的发育性癫痫脑病, 临床表型多变, 诊断、治疗困难, 相关共患病对患儿及家长的长期生活质量有深远的影响。SCN1A是Dravet综合征的主要致病基因, 超过85%的患儿存在SCN1A基因突变。近年来, 随着基因检测技术的发展和病例的积累, 对Dravet综合征的癫痫发作特点、共患病和SCN1A基因突变特点的认识也逐渐深入。除常规抗癫痫药物外, 新型抗癫痫药物(大麻二酚、芬氟拉明)亦显示出良好的抗癫痫作用, 有望成为治疗Dravet综合征癫痫发作的二线药物。该文主要对Dravet综合征较为独特的临床表型、SCN1A基因突变特点和新型抗癫痫药物研究进展进行综述, 以加深临床医生对该病的认识。     

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.     

幼儿间断抽搐1年半伴发育落后

该文报道1例吡哆醇依赖性癫癎患儿。患儿女,2岁时因发育落后,间断抽搐1年半就诊。患儿新生儿期曾有“缺氧”病史,婴儿期早期即出现难以控制的惊厥发作,部分性发作为主,多次癫癎持续状态,多种抗癫癎药物均不能控制发作。发热感冒时抽搐发作频繁。治疗前后多次视频脑电图及头颅MRI检查均正常。曾考虑诊断为Dravet综合征,后通过ALDH7A1基因检测确诊为吡哆醇依赖性癫癎。确诊后逐渐减停抗癫癎药物,仅单纯口服吡哆醇,发作基本控制。     

Dravet综合征患儿致病基因定位及GEFS+基因突变检测

目的分析海南地区Dravet综合征患儿的遗传特征。方法收集2015—2017年期间海南省18例Dravet综合征患儿及家系成员的外周血,采用PCR扩增及Sanger测序法进行SCN1A基因检测,运用连锁分析应用软件GenomeStudio进行致病基因定位分型与连锁分析;对Sanger测序法未发现SCN1A基因突变的患儿,采用多重连接依赖的探针扩增(MLPA)方法分析SCN1A基因片段缺失或重复,并筛查父母SCN1A基因,分析其突变来源。结果 18例Dravet综合征患儿及父母基因定位扫描结果完全符合亲子间的孟德尔遗传关系。SCN1A基因突变患儿可定位到5号、9号、22号染色体3个候选突变区域。其中5号染色体区域位于SNPRs 4957954至Rs 728937,在Rs 1459085处可获取到最大LOD值2. 13;9号染色体区域位于SNPRs 720974至Rs 1220087,在Rs 71332677处可获取到最大LOD值1. 92;22号染色体区域位于SNPRs 756658至Rs 713751,在Rs 374225处可获取到最大LOD值1. 91。18例患儿中,12例SCN1A基因突变,其中6例CDS区域的第5383位碱基呈现杂合变异(G→A),4例13号外显子和CDS区域的第2292位碱基纯合变异(T→C),2例SCN1A基因非编码区域碱基纯合变异(A→T)。结论海南Dravet综合征患儿的基因定位完全符合孟德尔遗传关系,推测Rs4957954至Rs728937、Rs720974至Rs1220087、及Rs756658至Rs713751区域是Dravet综合征的可能致病性区域。     

合并惊厥发作的X连锁Charcot-Marie-Tooth病1型1例报告并文献复习

目的分析X连锁Charcot-Marie-Tooth病1型(CMT1X)的发病机制及出现惊厥的可能原因。方法回顾分析1例合并惊厥发作的CMT1X患儿的临床特征以及基因检测结果,并复习相关文献。结果男孩,7岁6个月,以可逆性脑白质病变为首发症状且出现惊厥;基因检测显示患儿缝隙连接蛋白Bl (GJB1)基因发生突变,C.425GA(p.R142Q)。诊断为CMT1X。患儿与既往所报道病例的临床症状有差异。结论以惊厥为首发症状的CMT1X,系GJB1基因突变导致通道功能障碍所致,相同突变可出现不同临床表现。     

Coffin-Siris 综合征1 例报告

目的探讨Coffin-Siris综合征的临床表型及基因异常。方法回顾分析1例利用高通量测序技术确诊的Coffin-Siris综合征患儿的临床资料,并复习相关文献。结果患儿,男,生后即出现喂养困难、生长发育落后伴特殊面容。基因检测显示ARID1B基因c.6683CA(p.Ser2228*)变异,为新发变异,预测有致病性。结论 Coffin-Siris综合征为罕见遗传性疾病,早期临床诊断困难,基因检测有助确诊。     

Detection of a novel silent deletion,a missense mutation and a nonsense mutation in TCOF1

Background: Treacher Collins syndrome (TCS) is a disorder of craniofacial development, that is caused by mutations in the TCOF1 gene. TCS is inherited as an autosomal dominant trait, and haploinsufficiency of the TCOF1 gene product treacle is proposed to be etiologically involved. Methods: Mutational analysis of the TCOF1 gene was done in 10 patients diagnosed with TCS using single‐strand conformation polymorphism and direct sequencing. Results: Among these 10 patients, a novel 9 bp deletion was found, together with a previously reported 2 bp deletion, a novel missense mutation and a novel nonsense mutation in three different families. Familial studies allowed judgment of whether these abnormal findings were responsible for the TCS phenotype, or not. The 9 bp deletion of three amino acids Lys‐Glu‐Lys (1378–1380), which was located in the nuclear localization domain of treacle, seemed not essential for the treacle function. In contrast, the novel mutation of Ala26Val is considered to affect the LisH domain, an important domain of treacle. All of the mutations thus far detected in exon 5 have resulted in frameshift, but a nonsense mutation was detected (Lys159Stop). Conclusion: The information obtained in the present study provides additional insights into the functional domains of treacle.     

A strategy for studying a mutation

In this short survey, the author analyzes the main principles and some of the methods used for the analysis, at the molecular level, of a mutation causing a monogenic disease. The recent advances in molecular biology techniques allow the identification of such a molecular lesion in the human genome. A molecular probe, i.e. an isolated fragment of DNA, is the main tool for such a purpose; it is necessary for recognizing, isolating and analyzing an abnormal gene. When no molecular probe is available or when the primary defect responsible for the disease is unknown (Duchenne muscular dystrophy, cystic fibrosis), the strategy of "reverse genetics" briefly exposed here is a breakthrough in the molecular genetics of hereditary diseases.     

火棉胶样儿的基因突变分析一例

目的 确定1例火棉胶样儿的基因突变.方法 火棉胶样儿所涉及的突变基因很多,分析患儿临床表现后,依文献报道,选择突变发生率最高的基因--转谷丙酰胺酶基因1(TGM1)作为候选基因,采用PCR方法对TGM1基因的所有外显子及其旁侧内含子序列进行扩增,并进行PCR产物正反向直接测序.对错义突变设计等位基因特异性PCR引物,进行群体检验.结果 患儿TGM1基因存在3个新的异常:外显子3中c.463CT点突变,导致错义突变p.Arg155Trp;外显子4中缺失G(c.694delG),导致移码突变p.Glu232SerfsX98;外显子4中存在另1个c.578GA点突变,导致无义突变p.Trp193X.其父亲为c.694delG突变杂合子,母亲则为具有c.463CT、c.578GA双重突变的杂合子.c.463CT等位基因特异性PCR(AS-PCR)群体检验结果显示,正常对照人群中没有此突变.结论 该火棉胶样儿由TGM1基因突变引起,存在3种致病突变,其中两个突变(c.463CT/c.578GA)发生在母源等位基因,而另一个突变来源于父亲.     

Familial hypocalciuric hypercalcemia: a new mutation

Familial hypocalciuric hypercalcemia (FHH) is a cause of hypercalcemia with autosomal dominant pattern of inheritance and high penetrance. In most of the cases it can be shown to be due to an inactivating mutation on the gene coding for the calcium-sensing receptor (CaSR). Heterozygous cases usually do not present symptoms and they are diagnosed as an incidental finding. We report three affected children with an inactivating heterozygous mutation, p.Phe789del, in exon 7 of the calcium-sensing receptor gene (CASR gene), situated in chromosome 3q21 (Ensembl ENSG00000036828), which results in elevated serum calcium, normal o high level of parathyroid hormone (PTH) and reduced urinary excretion with hypocalciuria. It is very important to determine the difference between FHH and primary hyperparathyroidism. Therefore, in a mild to moderate PTH-dependent hypercalcemia we must perform a family study and determine the urinary excretion of calcium. The presence of any other affected family member or reduced urinary calcium excretion is enough to suspect FHH, and this should be confirmed by the mutational analysis of the CASR gene, in order to establish the correct diagnosis, differentiated from primary hyperparathyroidism, to avoid unnecessary investigations or operations.     

Griscelli syndrome: Rab 27a mutation

An infant with partial albinism was suspected to have Chediak-Higashi syndrome because two of his elder siblings had albinism and died in childhood following accelerated phase. Detailed investigations of blood, hair and skin of the proband revealed that he had Griscelli syndrome.     

Primary hyperoxaluria type 1 with a novel mutation

Primary hyperoxaluria type 1 [PH1] is an autosomal recessive disorder caused by a deficiency of alanine-glyoxylate aminotransferase AGT, which is encoded by the AGXT gene. We report an Indian family with two affected siblings having a novel mutation in the AGXT gene inherited from the parents. The index case progressed to end stage renal disease at 5 months of age. His 4 month old sibling is presently under follow up with preserved renal function.     

Hepatoblastoma in a Noonan syndrome patient with a PTPN11 mutation

Although Noonan syndrome (NS) is occasionally associated with embryonal solid tumors, there has been no report of hepatoblastoma in NS. We identified hepatoblastoma spreading into bilateral hepatic lobes in a 1-month-old NS patient with a heterozygous PTPN11 mutation (Asn308Asp). This finding suggests the potential relevance of constitutively activated RAS/MAPK signaling in the development of hepatoblastoma.