结节性硬化症TSC2基因5238-5255 del 18 bp及2713 C>T基因突变分析

目的检测并分析2例中国汉族结节性硬化症(tuberous sclerosis complex,TSC)患者TSC2基因突变特点。方法采用直接测序法对31个家系的34例TSC患者及其父母33名进行TSC1基因和TSC2基因全长编码外显子基因检测。测序后发现第25家系先证者为TSC2基因外显子40的框内移码突变5238-5255 del 18 bp,第11家系先证者为TSC2基因外显子23错义突变Arg905Trp。进一步采用变性凝胶电泳及内切酶技术在患者与120名正常对照中检测这两种突变。结果第25家系先证者外显子40出现5238-5255d el CATCAAGCGGCTCCGCCA突变,导致6个氨基酸缺失的框内移码突变(1746-1751del His-Ile-Lys-Arg-Leu-Gly),第11家系先证者外显子23出现2713 C>T(Arg905Trp)错义突变,2713位碱基由胞嘧啶(C)改变为胸腺嘧啶(T),导致第905位氨基酸精氨酸被色氨酸替代。120名正常对照未检测到这两种突变。结论TSC2基因5238-5255 del 18 bp及2713 C>T突变为两种致病性突变。     

X连锁Charcot-Marie-Tooth病1型六个家系的病理和基因突变特点

目的 报道6个X连锁Charcot-Marie-Tooth病1型(CMTX1)家系的神经病理和基因型改变特点.方法 6个CMTX1家系的先证者均为男性,发病年龄11 ～24岁,出现下肢远端为主的肌无力、腱反射减低和轻度感觉减退.先证者1伴随发作性白质脑病,先证者5伴随小脑性共济失调.12名家系成员也出现周围神经损害症状,另7名存在高弓足或腱反射减低.对6例先证者行腓肠神经活体组织检查,并对6例先证者、8名受累家庭成员和10名无症状家系成员及50名健康女性进行缝隙连接蛋白32( Cx32)基因测序.结果 6例先证者有髓神经纤维出现轻-中度减少伴轴索再生变性,5例出现薄髓鞘神经纤维,其中3例伴洋葱球样结构,2例伴炎细胞浸润.6个家系的Cx32基因存在5种新突变和1种同义突变,即L20T、I127F、D178G、A197V错义突变,403_404T insT插入突变和L10L沉默突变,10名无症状家系成员中有4名女性为携带者,6名男性和健康对照均没有这些基因突变.结论 该组CMTX1患者的周围神经病理改变以慢性轴索损害为主,Cx32基因较多新突变的出现提示我国CMTX1患者具有个体突变特点.     

一个肌张力障碍-帕金森综合征的家系调查及致病基因研究

目的初步分析一个肌张力障碍-帕金森综合征家系的可能致病基因。方法对一个肌张力障碍-帕金森综合征的家系进行家系调查。在收集先证者相关血液生化指标、超声波、MRI影像学和PET核医学检查等临床资料基础上,对先证者及其家系三代共8人先后进行了目标基因以及全外显子基因测序加可疑位点Sanger测序验证。结果先证者临床表现为眼睑、口面、下肢肌张力异常,伴动作慢、肌张力高和震颤等典型肌张力障碍-帕金森综合征症状,多巴胺能药物不敏感及服药后罕见的阴道出血不良反应。血生化、铜蓝蛋白、肝脏超声及角膜裂隙灯照相、头颈及腰段脊髓MRI扫描均正常,头颅¹⁸F-dopa PET/MRI显像提示双侧豆状核多巴胺神经元受损。该家系三代共9人中出现症状2例(1例已死亡),基因检测显示先证者及另外3人携带父源的RYR1基因36号外显子c.5972C>T (p.T1911I)杂合突变;另有SETX基因外显子10的c.2439A>C (p.E813D)杂合突变;GCDH基因外显子10的c.1060G>A (p.G354S)杂合突变;ATP7B基因外显子18的c.3792G>C ...     

夏科-马里-图斯病2A2型一家系的临床病理特点

目的 报道一个早发型夏科-马里-图斯病(CMT)2A2家系,探讨其临床和病理特点.方法 该家系共有5例患者,呈常染色体显性遗传,先证者为36岁女性,6岁开始出现下肢进行性无力,8岁出现双足内翻.家族中另有2例男性和2例女性发病,发病年龄3～7岁,主要表现为缓慢进展的四肢远端肌肉无力、萎缩,伴随四肢远端感觉减退、腱反射减退及关节挛缩.先证者和其儿子的上肢感觉神经、下肢感觉和运动神经诱发电位波幅不能引出.对先证者左侧腓肠神经进行活体组织病理检查.对先证者和其他4例家系患者、3名无症状家系成员行MFN2基因测序.结果 病理检查可见腓肠神经有髓纤维数目重度减少,以大有髓神经纤维减少为主,伴随个别有髓神经纤维再生簇结构以及不典型的洋葱球样结构.电镜下可见轴索中线粒体聚集,未发现线粒体结构异常.5例患者存在MFN2基因R94W突变,无症状家系成员无此突变.结论 我国存在早发型CMT2A2家系,患者周围神经缺乏有髓神经纤维再生改变,提示MFN2基因突变对神经元的损害更大.     

一个2A型肢带型肌营养不良家系CAPN3基因的突变分析

目的对一个2A型肢带型肌营养不良(limb-girdle muscular dystrophy type 2A)家系进行CAPN3基因的致病突变分析。方法收集先证者及家系成员的外周血,提取DNA,应用全外显子测序技术对先证者进行致病基因检测,然后用Sanger测序技术对先证者家系成员进行突变位点的验证。结果全外显子测序发现先证者携带CAPN3基因c. 1194-9A G和c. 1437C T (p. ser479=)的复合杂合突变。Sanger测序验证先证者母亲为CAPN3基因c. 1194-9A G变异携带者。家系中其他患者均存在相同的复合杂合突变,其未发病的姐姐和女儿为CAPN3基因c. 1437C T (p. ser479=)变异携带者,先证者的女婿未检测到上述位点变异。结论 CAPN3基因c. 1194-9A G和c. 1437C T (p. ser479=)的复合杂合突变为该家系的致病原因。     

骨骼肌钠通道α1亚基基因R1129Q新突变导致正常钾和低钾性周期性瘫痪一家系

目的 报道1个骨骼肌钠通道α1亚基(SCN4A)基因新突变导致的正常钾和低钾性周期性瘫痪家系的临床和病理改变特点.方法 本家系为常染色体显性遗传,共有9例患者,男性4例,女性5例,发病年龄7～25岁.5例患者为正常钾性周期性瘫痪,其中4例伴随肌强直症状;3例患者为低钾性周期性瘫痪;1例发作时血钾浓度不详.对先证者进行左肱二头肌活体组织检查.先证者和7例家系患者、3名无症状家系成员以及50名健康人行SCN4A基因测序.结果 先证者的肌纤维出现轻度肥大和萎缩,伴随核内移和肌纤维内空泡,部分肌纤维内氧化酶分布异常.所有患者均存在SCN4A基因的R1129Q突变,3名无症状家系成员以及50名健康对照无此突变.结论 SCN4A基因R1129Q新突变在同一家系内可以导致低血钾性和正常血钾性周期性瘫痪共存.     

骨骼肌钠通道α1亚基基因R1129Q新突变导致正常钾和低钾性周期性瘫痪一家系

目的 报道1个骨骼肌钠通道α1亚基(SCN4A)基因新突变导致的正常钾和低钾性周期性瘫痪家系的临床和病理改变特点.方法 本家系为常染色体显性遗传,共有9例患者,男性4例,女性5例,发病年龄7～25岁.5例患者为正常钾性周期性瘫痪,其中4例伴随肌强直症状;3例患者为低钾性周期性瘫痪;1例发作时血钾浓度不详.对先证者进行左肱二头肌活体组织检查.先证者和7例家系患者、3名无症状家系成员以及50名健康人行SCN4A基因测序.结果 先证者的肌纤维出现轻度肥大和萎缩,伴随核内移和肌纤维内空泡,部分肌纤维内氧化酶分布异常.所有患者均存在SCN4A基因的R1129Q突变,3名无症状家系成员以及50名健康对照无此突变.结论 SCN4A基因R1129Q新突变在同一家系内可以导致低血钾性和正常血钾性周期性瘫痪共存.     

抗肌萎缩蛋白病一家系的临床、分子病理及遗传学特点

目的 分析并确定1个抗肌萎缩蛋白病(dystrophinopathy)家系的临床、分子病理及遗传学特征.方法 收集先证者及其家系成员的临床资料,对先证者行肌肉活体组织检查,采用抗层黏连蛋白α2(1aminin α2,又称merosin)、抗emerin蛋白、抗肌萎缩蛋白(dystrophin)中央棒状区(Dys1)、C′末端(Dys2)、N′末端(Dys3)单克隆抗体行免疫组织化学染色;提取外周血基因组DNA,采用多重连接探针扩增(MLPA)进行抗肌萎缩蛋白Duchenne型肌营养不良(DMD)基因检测.结果 该家系中包括先证者在内共有3例患者临床诊断为肌营养不良,均无腓肠肌肥大,但病情重、进展较快,同时先证者肌肉活体组织检查行免疫组织化学染色提示dystrephin蛋白部分缺失,merosin、emerin染色呈阳性表达.MLPA检测显示先证者DMD基因第45～54外显子缺失,其母在第45～54外显子区域为杂合性缺失.结论 该家系中的先证者DMD基因为第45～54外显子缺失,突变基因来自母亲,其母为表型正常的携带者.dystrophin蛋白表达异常是造成抗肌萎缩蛋白病表型的病理基础,其临床后果不仅取决于dystrophin蛋白表达缺失的程度,还取决于DMD基因缺失区域的功能.     

遗传性多巴反应性肌张力障碍一家系

目的 探讨一个遗传性多巴反应性肌张力障碍(dopa-responsive dystonia,DRD)家系的临床特点及相关基因突变.方法 收集一个DRD家系的临床资料及外周血样本,提取全基因组DNA,应用聚合酶链反应(PCR)及DNA直接测序方法进行三磷酸鸟苷环化酶-1(GCH-1)基因外显子突变检测.结果 该家系患病成员临床特点方面个体差异较大,但所有患者均对左旋多巴制剂反应良好,且未见明显不良反应.基因分析显示5例患者及1例无症状直系亲属存在GCH-1基因第6号外显子上的缺失突变c.63 1_632delAT,引起框移突变.结论 DRD临床表现具有明显异质性,在同一家系不同患者之间存在较大差异,同一基因突变可引起不同的临床表现型,部分携带者可不发病.GCH-1基因第6号外显子上的缺失突变c.631_632delAT为DRD致病的遗传学基础之一.     

D uchenne 型肌营养不良家系的临床及分子遗传学研究

目的：探讨Duchenne型肌营养不良（DMD）家系的临床及分子遗传学特征。方法收集并分析我院收治的2个DMD家系临床资料和基因检测结果,并结合既往相关文献,回顾该病在临床表现、分子遗传学等方面的特点。结果DMD儿童期隐匿起病,进行性加重,以肌无力、肌萎缩为特点,可伴肌肉假性肥大,血清肌酶水平异常增高,肌电图呈肌源性损害,肌肉活检呈肌病特征。本文报道的2个家系经基因检测家系1先证者为DMD基因的第3～21号外显子缺失,家系2先证者则为第8、9外显子重复突变,2个家系中的先证者基因均为纯合突变,且其母亲均为致病基因的携带者,符合X染色体隐性遗传的规律。结论早期识别DMD的临床特征有助于提高该病的诊断水平,基因检测是一种确诊DMD快速、有效的方法。     

A novel heterozygous deletion–insertion mutation (2695–2712 del/GTTTGT ins) in exon 18 of the filamin C gene causes filaminopathy in a large Chinese family

Filaminopathy represents a rare subgroup of myofibrillar myopathies caused by mutation in filamin C gene. We present a Chinese family with filaminopathy, characterized by onset at the age of 35–40 years with progressive muscle weakness in all limbs. Mild cardiac symptoms and chronic diarrhea were present in a few patients. Muscle biopsy revealed numerous spheroid bodies and amorphous deposits in the fibers, which were positive for desmin, dysferlin, dystrophin and ubiquitin, but negative for α-actinin and α-synuclein. Ultrastructural analysis revealed inclusions composed of disorganized thin filaments and interspersed electron-dense granules, accumulating in spheroid or cytoplasmic structures. A novel complex mutation of 18-nucleotide deletion and 6-nucleotide insertion was identified in exon 18 of the filamin C gene, resulting in an in-frame 6 amino acid deletion (Lys899-Val904) and a 2 amino acid insertion (Val 899-Cys900) in the seventh Ig-like repeat of filamin C. Our findings expand the genetic spectrum and geographic distribution of filaminopathy.     

A rare Cu/Zn superoxide dismutase mutation causing familial amyotrophic lateral sclerosis with variable age of onset and incomplete penetrance in China.

More than 100 mutations in the Cu/Zn superoxide dismutase (SOD) gene have been found, accounting for about 20% of familial ALS (FALS). However, few have been identified in Chinese patients with FALS. We present a five-generation Chinese family with FALS with a rare mutation in exon 4 of the Cu/Zn SOD gene codon position 105, converting serine to leucine. Forty-seven family members including the proband were examined clinically; two affected persons had EMG and nerve conduction studies. Genomic DNA was extracted from peripheral blood leukocytes of the family members after informed consent. All five exons of the Cu/Zn SOD gene were amplified by polymerase chain reaction (PCR) and DNA sequencing was performed on purified products. Exon 4 of the Cu/Zn SOD gene was amplified from genomic DNA isolated from not only the family members but also from 50 unrelated healthy Chinese control subjects. A rare S105L mutation, which is heterozygous with C by T at position 1,125 of the coding sequence in exon 4 of the Cu/Zn SOD gene, was found in the proband and her affected elder brother. The clinical phenotype within the FALS patients in this family is relatively variable. The age at onset ranged from 32 to 65 years, with initial symptoms in either the upper or lower extremities in different family members. Two subjects aged 72 and 60 years remained asymptomatic until their death from other causes, although their offspring carrying the same mutation have already developed clinical evidence of the disease. The S105L mutation was identified in another seven asymptomatic family members, aged 7 to 59 years. It is concluded that the S105L mutation in exon 4 of the Cu/Zn SOD gene is pathogenic. The phenotype is characterized by relatively variable clinical symptoms, with incomplete penetrance.     

伴皮质下梗死及白质脑病常染色体显性遗传性脑动脉病的NOTCH3基因诊断

目的 分析伴皮质下梗死及白质脑病常染色体显性遗传性脑动脉病((CADASIL)的NOTCH3基因突变类型.方法 对临床诊断为CADASIL的4例先证者、来自3个家系10例患者及4例无类似临床表现成员、以及100名健康对照者进行NOTCH3基因PCR扩增及变性高压液相色谱分析(DHPLC)检测;对DHPLC阳性结果进行DNA双向测序,明确致病性突变或多态类型.结果 在CADASIL先证者及其家系患者中共发现134半胱氨酸→酪氨酸(Cys134Tyr)、141精氨酸→半胱氨酸(Arg141Cys)、90精氨酸→半胱氨酸(Arg90Cys)3种突变类型,存在于第3、第4外显子,为杂合错义突变.同时发现15种多态类型.其中家系1和家系2中分别发现1名成员与先证者存在相同位点的NOTCH3基因致病性突变,尚未出现与先证者相应的临床表现,被确定为临床前期患者.结论 NOTCH3单基因突变是CADASIL的分子遗传学基础,第3、4外显子可能是中国CADASIL家系的热点突变区.第4外显子Cys134Tyr突变类型为国内首次报告.     

Novel FLNC mutation in a patient with myofibrillar myopathy in combination with late-onset cerebellar ataxia

Introduction: Mutations in the gene that encodes filamin C, FLNC, represent a rare cause of a distinctive type of myofibrillar myopathy (MFM). Methods: We investigated an Italian patient by means of muscle biopsy, muscle and brain imaging and molecular analysis of MFM genes. Results: The patient harbored a novel 7256C>T, p.Thr2419Met mutation in exon 44 of FLNC. Clinical, pathological and muscle MRI findings were similar to the previously described filaminopathy cases. This patient had, in addition, cerebellar ataxia with atrophy of cerebellum and vermis evident on brain MRI scan. Extensive screening failed to establish a cause of cerebellar atrophy. Conclusions: We report an Italian filaminopathy patient, with a novel mutation in a highly conserved region. This case raises the possibility that the disease spectrum caused by FLNC may include cerebellar dysfunction. Muscle Nerve 275–282, 2012     

中国汉族人群早发性帕金森综合征DJ-1基因突变分析

目的 探讨中国汉族人群早发性帕金森综合征(early-onset parkinsonism,EOP)DJ-1基因突变情况.方法 应用实时荧光定量聚合酶链反应(PCR)结合DNA直接测序技术对160例EOP患者进行了DJ-1基因突变分析.结果 对DJ-1基因外显子重排突变分析发现,4例新的DJ-1基因外显子2的杂合缺失突变,突变频率2.5%(4/160);DNA直接测序方法未发现DJ-1基因的致病突变,发现了4种已报道的单核苷酸多态(SNP)和1种新的SNP,分别为:IVS4+30 T→G、IVS4+45 G→A、IVS4+46 G→A、IVS5+31 G→A和IVS6+52 C→T.结论 DJ-1基因外显子2的杂合缺失突变扩展了DJ-1基因的突变谱,可能是中国汉族人群EOP DJ-1基因突变的重要形式.     

中国南方汉族散发早发性帕金森综合征的parkin基因突变分析

目的 探讨中国南方汉族散发早发性帕金森综合征(early onset parkinsonism,EOP)的parkin基因突变特点.方法 应用实时荧光定量PCR技术结合DNA直接测序技术对156例中国南方汉族散发EOP患者进行parkin基因突变分析.结果 19例患者parkin基因突变,包括15例杂合突变、2例纯合突变、2例复杂杂合突变.17例患者外显子重排突变,其中12例外显子缺失突变,5例外显子双重重复突变.此外,3例患者存在点突变和(或)小片段缺失突变,其中ⅣS9+18C＞T、c.202-203delAG为已报道突变,c.813delT为未报道的新突变;parkin基因突变位点主要分布在其1～7号外显子.无parkin基因突变与有parkin基因突变的患者在临床表现及病情严重程度方面差异无统计学意义,但发病年龄[(40.9±6.8)岁与(35.5±10.0)岁,Z=-2.271,P=0.023)]、病程[(4.4±3.6)年与(7.6±4.0)年,Z=-3.680,P=0.000)]等方面差异有统计学意义.结论 中国南方汉族散发EOP患者parkin基因突变的频率为12.18%(19/156),外显子重排突变是其重要突变类型;外显子缺失突变是主要的突变形式;parkin基因1～7号外显子为突变热点.parkin基因突变与无parkin基因突变的EOP患者在临床表型上无明显差异,但其发病年龄较轻,病程较长,进展较缓慢.     

A Chinese CADASIL Family with a Novel Mutation on Exon 10 of Notch3 Gene

BackgroundCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which is caused by the Notch3 gene mutation, has its unique clinical and imaging characteristics. Here we present a Chinese family with a novel mutation on exon 10 of Notch3 gene.MethodsClinical and MRI data of the three patients in the family during the 7-year follow-up were collected. The CADASIL Scale Score was calculated to evaluate the disease risk of the three patients at their first admission or clinic visit. Five family members underwent genetic test.ResultsGenetic test confirmed the diagnosis of CADASIL in this family. A novel mutation of p.C533S on exon 10 of Notch3 gene was detected. The CADASIL score of the proband and her sister was both 17 and that of her brother was 14.ConclusionsOur report not only expands the mutation spectrum of Notch3 gene in CADASIL, but also shows the distinct heterogeneity of CADASIL patients in the same family with the same mutation.