河南地区两个腓骨肌萎缩症家系PMP22基因突变研究

目的分析在河南地区两个腓骨肌萎缩症(CMT)家系的临床表现及PMP22基因重复突变的特点。方法收集两家系中21名成员的临床资料,并应用等位基因特异性PCR-双酶切方法检测17p11.2-1 PMP22基因重复(即1760 bp片段)序列的情况,同时选择50名健康人做为对照。结果两家系中共14名成员经等位基因特异性PCR-双酶切方法检测出PMP22基因大片重复(即1760 bp片段)序列;家系一患病者有3名(Ⅱ5、Ⅱ7、Ⅲ11),无临床症状但基因检测结果示PMP22基因重复突变为携带者有6名(Ⅱ9、Ⅲ6、Ⅲ8、Ⅲ10、Ⅳ1、Ⅳ2);家系二患病者有4名(Ⅱ3、Ⅱ9、Ⅱ11、Ⅲ7),携带者只有Ⅲ5。两家系中余7人及健康对照50人均未检测出上述重复突变。结论 PCR-双酶切法检测PMP22特异性基因重复序列在早期诊断CMT有重要价值。     

周围髓鞘蛋白22基因重复突变致夏科-马里-图斯病1A亚型的临床变异性

目的 探讨夏科-马里-图斯病(CMT)患者周围髓鞘蛋白22(PMP22)基因重复突变特征及临床变异性.方法 联合应用改良的等位基因特异性PCR-双酶切和基于荧光标记毛细管电泳短串联重复序列(STR)分析对45例临床拟诊CMT患者进行PMP22基因重复突变的检测,详细分析其中阳性病例的临床特征.结果 在45例拟诊CMT患者中共检测出PMP22基因重复病例21例,包括10例临床特征符合四肢远端萎缩无力的典型CMT1型患者和11例不典型的CMT患者,后者具有特殊表型:1例仅以轻度头晕就诊;1例合并听力障碍;2例以反复发作性肢体无力起病;2例伴有上肢姿势性震颤;4例伴有小脑性共济失调;1例伴有癫(癎)发作.结论 PMP22基因重复突变为CMT病最常见的病因,改良的等位基因特异性PCR-双酶切提供了一种准确、可靠并易于操作的检测方法,有助于该病的诊断和鉴别.同时,通过综合分析PMP22重复突变阳性的CMT1A患者临床表现、电生理及病理特征,提示该组疾病具有高度的临床变异性.     

腓骨肌萎缩症基因重复异常的检测

目的应用分子生物学方法对腓骨肌萎缩症(CMT)患者进行外周髓鞘蛋白(PMP22)基因重复异常的检测。方法应用多聚酶链反应(PCR)加双酶切的方法,对临床上诊断为腓骨肌萎缩症14个家系的先证者和47例散发患者及20例正常人进行基因重复异常研究,根据有无1760bp大小的酶切片断来判断是否为PMP22基因重复异常。结果13个家系检测出PMP22基因重复异常,占所收集家系的92.86%;28例散发者检出PMP22基因重复异常,占散发病例59.57%。结论PCR-双酶切法检测CMT基因重复异常比较快速、简单、易操作,目前为CMT1A型基因诊断首选方法。     

腓骨肌萎缩症1型患者肌电图及PMP22基因特点分析

目的探讨和研究腓骨肌萎缩症1型(Charcot-Marie-Tooth disease 1,CMT1)患者肌电图和PMP22基因改变特点。方法对43例CMT1患者进行常规神经传导速度和肌电图检查,应用PCR双酶切方法对其中33例CMT1患者及15名健康志愿者(对照组)检测17p11.2-12 PMP22基因重复序列(即1760bp片段)。33例CMT1患者依有无17p11.2-12 PMP22基因特异性片段分为PMP22基因特异性片段阳性组与阴性组,比较两组患者神经传导改变有无差异。结果 43例患者均行肌电图检测,均表现为运动或感觉神经传导速度存在明显减慢(100%),感觉神经病变重于运动神经,下肢受累程度重于上肢;所检129块肌肉中,88块(68.2%)呈神经源性损害。经PMP22基因学检测的33例中20例(60.6%)检测出1760bp片断,对照组均未检测到此片段。PMP22基因特异性片段阳性组感觉神经传导速度、运动神经传导速度及远端潜伏期与阴性组比较差异均无统计学意义(P0.05)。结论 CMT1患者肌电图改变具有其特异性,结合PCR-双酶切法检测PMP22特异性基因重复序列可提高诊断CMT1的准确性及敏感性。     

腓骨肌萎缩症(CMT)1型的临床、神经电生理及CMT1A型基因诊断方法的研究

目的 观察腓骨肌萎缩症(CMT)1型患者的临床表现及神经电生理特点,同时利用两种不同方法检测CMT1A型相关基因是否存在突变,并分析两种方法的临床应用价值以进一步确定CMT1A型的诊断.方法 对临床确诊为CMT1型的5例患者进行详细的临床及神经电生理检查,同时对所有患者利用等位基因特异性PCR及MLPA两种方法进行PMP22基因重复突变检测.结果 4例患者20岁前发病,其中2例有家族史,1例患者30岁左右发病.临床特点为进行性四肢远端无力伴肌萎缩,四肢远端感觉减退,腱反射均减弱或消失,2例患者出现弓型足.神经电生理检查示神经传导速度减慢,波幅轻度降低.两种基因检测均发现1例患者存在PMP22基因重复突变.结论 CMT1型发病年龄较早,主要表现为进行性四肢无力伴肌萎缩,神经电生理可见神经传导速度明显降低,波幅略有降低.等位基因特异性PCR和MLPA两种方法检测基因突变结果一致.     

一个特殊伴2型糖尿病的腓骨肌萎缩症家系基因突变检测

目的探讨合并2型糖尿病的腓骨肌萎缩症(CMT)一家系临床特点及可能的分子生物学发生机制。方法对40名家系成员进行详细家系调查、临床及辅助检查,并运用实时荧光PCR、普通PCR及基因测序等方法检测周围神经髓鞘蛋白22(peripheral myelin protein 22,PMP22)和髓鞘糖蛋白零(myelin protein zero,MPZ)基因有无突变。结果家系成员中5例经临床诊断为腓骨肌萎缩症1型(CMT1),其中4例伴2型糖尿病。该家系成员未发现PMP22基因大片段扩增突变及点突变;仅发现1例MPZ基因5820位点A→G多态性现象。结论 PMP22和MPZ基因突变不是本组合并2型糖尿病CMT家系的致病基因,需要进一步研究以明确该家系基因遗传规律。     

腓骨肌萎缩症2个家系的临床、电生理和基因学研究

为了研究腓骨肌萎缩症(CMT)的临床、电生理以及基因突变的特点,该研究收集2个家系先证者以及发病亲属的临床资料、电生理资料、全血和DNA,进行家系分析及CMT相关基因检测.结果发现家系1为常染色体显性遗传,患者MLPA检测提示PMP22基因的重复扩增.基因测序未发现患者携带CMT其他相关基因的突变.进一步在患者的3个患病的亲属中发现携带PMP22基因的重复扩增,并且未发现其未患病的叔叔携带该突变.家系2为常染色体隐性遗传,先证者携带SH3TC2基因的c.730C＞T p.Q244X和c.432C＞G p.Y144X两个杂合突变.患者的父母,则分别携带上述两个突变.因此,家系1诊断为CMT1A型,家系2诊断为CMT4C型,临床实践中应注意基因和表型的联系.     

X连锁腓骨肌萎缩症Cx32基因的突变、临床和电生理特点

目的 分析X连锁腓骨肌萎缩症（CMTX）患者Cx32基凶的突变及其临床表现和电生理特点、方法应用多聚酶链反应一单链构象多态性分析结合DNA直接测序的方法，对24例无周围髓鞘蛋白（PMP）22基因大片段重复突变，家系中无男传男的腓骨肌萎缩症（CMT）先证者进行Cx32基因的突变分析；对先证者及其家系内患者进行临床和电生理检查。结果 在6个X连锁遗传家系和1例散发患者中发现了7个不同的Cx32基因突变，其中4个家系临床分型为CMTI型，2个家系为CMT中间型，散发病例为CMT1型检测到有Cx32基因突变的家系成员共38例，其巾男性20例，全部为CMTX患者；女性18例，其中6例为CMTX患者，12例为无临床症状的携带者；26例患者均为周围神经轻、中度受累。结论 CMTX的遗传方式可为X连锁显性、X连锁隐性遗传，也可为散发。根据临床和电生理特点分为CMTI型或CMT中间型，多为周围神经轻、中度受累，男性患者的症状通常较女性重。在没有检测到PMP22基因大片段重复突变和无男传男的CMT家系中应首先进行Cx32基因突变分析。     

Huntington病两家系基因分析

目的 建立准确而快速的IT15基因胞嘧啶-腺嘌呤-鸟嘌呤(CAG)重复序列检测方法,并应用于Huntington病患者的基因诊断及症状前诊断.方法 应用聚合酶链反应、聚丙烯酰胺凝胶电泳及DNA测序技术对Huntington病两家系中的15名成员进行IT15基因CAG重复数目的检测及分析.结果 两家系中共计检出8名成员携带异常的IT15基因,其中2例先证者CAG重复序列存在异常扩增,1例(AⅡ4)出现Huntington病临床表现,其余5例尚未出现Huntington病临床症状与体征.结论 IT15基因CAG重复序列的异常扩增是Huntington病的发病基础,应用上述检测方法对IT15基因CAG重复序列进行检测可对Huntington病患者进行准确的基因诊断及症状前诊断.     

高通量测序技术与多重连接探针依赖扩增技术在PMP22全基因分析中的应用比较

目的探讨高通量测序技术与多重连接探针依赖扩增(MLPA)技术检测周围神经髓鞘蛋白22基因(PMP22)全基因突变中的应用比较。方法收集5例拟诊为腓骨肌萎缩症1型(CMT1)/遗传性压迫易感性神经病(HNPP)患者的外周血标本,采用高通量测序技术进行PMP22基因检测。结果高通量测序技术检测的基因全长捕获测序分析发现PMP22基因缺失突变1例,重复突变3例,所得结果与MLPA检测结果一致;点突变1例与一代测序(Sanger测序)结果一致。结论应用高通量测序技术不仅能准确检测出PMP22基因点突变,还能检出外显子缺失和重复突变,为CMT1和HNPP患者的早期诊断、鉴别诊断、预后判断及产前诊断提供遗传学帮助,成为一站式PMP22基因检测平台。     

PMP22‐Related neuropathies and other clinical manifestations in Chinese han patients with charcot‐marie‐tooth disease type 1

Introduction: Most cases of Charcot‐Marie‐Tooth (CMT) disease are caused by mutations in the peripheral myelin protein 22 gene (PMP22), including heterozygous duplications (CMT1A), deletions (HNPP), and point mutations (CMT1E). Methods: Single‐nucleotide polymorphism (SNP) arrays were used to study PMP22 mutations based on the results of multiplex ligation‐dependent probe amplification (MLPA) and polymerase chain reaction–restriction fragment length polymorphism methods in 77 Chinese Han families with CMT1. PMP22 sequencing was performed in MLPA‐negative probands. Clinical characteristics were collected for all CMT1A/HNPP probands and their family members. Results: Twenty‐one of 77 CMT1 probands (27.3%) carried duplication/deletion (dup/del) copynumber variants. No point mutations were detected. SNP array and MLPA seem to have similar sensitivity. Fifty‐seven patients from 19 CMT1A families had the classical CMT phenotype, except for 1 with concomitant CIDP. Two HNPP probands presented with acute ulnar nerve palsy or recurrent sural nerve palsy, respectively. Conclusions: The SNP array has wide coverage, high sensitivity, and high resolution and can be used as a screening tool to detect PMP22 dup/del as shown in this Chinese Han population. Muscle Nerve 52 : 69–75, 2015     

腓骨肌萎缩症1A型的临床、神经电生理和疾病基因突变分析

目的　观察腓骨肌萎缩症 (CMT) 1A型的临床、神经电生理特点和疾病基因的突变分析。方法对一CMT家系中 9个成员进行详尽的临床检查、疾病基因突变分析 ,对先证者进行神经电生理检查和神经肌肉活检。结果　本家系中 5人发病 ,符合常染色体显性遗传模式 ,除 1例患者无临床症状外 ,其余 4例均在2 0岁前起病。临床特点为进行性四肢远端肌无力、肌萎缩 ,末梢型感觉障碍 ,腱反射减弱或消失 ,足部畸形(高弓足 )。神经电生理检查示运动和感觉神经传导速度减慢。基因突变分析发现 17号染色体短臂 11 2区(17p11 2 )包含周围髓鞘蛋白 (PMP) 2 2基因的正向串联重复突变。结论　CMT1A型是CMT最常见类型 ,多于儿童期或青少年期起病 ,表现为进行性四肢远端肌无力、肌萎缩 ,腱反射减弱或消失。神经电生理特点为运动神经传导速度均一性减低 (<38m/s)。 17p 11 2区包含PMP 2 2基因在内的 1 5Mb(偶尔 <1 5Mb)的正向串联重复突变是CMT 1A最主要的突变型。     

Application of multiplex ligation-dependent probe analysis to define a small deletion encompassing PMP22 exons 4 and 5 in hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies arises as a result of defects at the chromosome 17p11.2-12 locus and in 84% of cases a 1.5 Mb deletion containing the PMP22 gene is detected by analysis that utilises polymorphic (CA)_n repeat markers which flank this gene. We report the clinical and electrophysiological findings observed in a kindred with three members affected by HNPP due to a deletion containing exons 4 and 5 of the PMP22 gene. This small deletion cannot be detected using standard analysis with polymorphic (CA)_n repeat markers and a definitive diagnosis was made by multiplex ligation-dependent probe analysis of PMP22 exons 1A-5. MLPA can be readily utilised as a routine diagnostic laboratory test to detect the common HNPP 1.5 Mb deletion, as well as the reciprocal 1.5 Mb insertion observed in CMT1A, but has the advantage over other diagnostic techniques of being able to define single exon deletions.     

Rapid genetic screening of Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsies patients

We used the allele-specific PCR-double digestion method on peripheral myelin protein 22 (PMP22) to determine duplication and deletion mutations in the proband and family members of one family with Charcot-Marie-Tooth disease type 1 and one family with hereditary neuropathy with liability to pressure palsies. The proband and one subclinical family member from the Charcot-Marie-Tooth disease type 1 family had a PMP22 gene duplication; one patient from the hereditary neuropathy with liability to pressure palsies family had a PMP22 gene deletion. Electron microscopic analysis of ultrathin sections of the superficial peroneal nerve from the two probands demonstrated demyelination and myelin sheath hyperplasia, as well as an ’onion-like’ structure in the Charcot-Marie-Tooth disease type 1A patient. We observed an irregular thickened myelin sheath and ’mouse-nibbled’-like changes in the patient with hereditary neuropathy with liability to pressure palsies. In the Charcot-Marie-Tooth disease type 1A patient, nerve electrophysiological examination revealed moderate-to-severe reductions in the motor and sensory conduction velocities of the bilateral median nerve, ulnar nerve, tibial nerve, and sural nerve. Moreover, the compound muscle action potential amplitude was decreased. In the patient with hereditary neuropathy with liability to pressure palsies, the nerve conduction velocity of the bilateral tibial nerve and sural nerve was moderately reduced, and the nerve conduction velocity of the median nerve and ulnar nerve of both upper extremities was slightly reduced.     

夏科-马里-图思病Cx32、MPZ和PMP22基因点突变的特点

目的研究我国夏科马里图思病（ＣＭＴ）Ｃｘ３２、ＭＰＺ和ＰＭＰ２２基因点突变的特点。方法应用聚合酶链反应单链构象多态性（ＰＣＲＳＳＣＰ）结合ＤＮＡ序列分析检测３０个ＣＭＴ家系的患者及５０名非血缘关系的正常对照的Ｃｘ３２、ＭＰＺ和ＰＭＰ２２基因的编码外显子。结果４个家系（３个为Ｘ连锁隐性遗传）有４种不同的Ｃｘ３２基因点突变（１３．３％）,其中１个家系为１８８位的苏氨酸被丙氨酸置换是未见报道的新突变。１个家系（３．３％）有ＭＰＺ基因点突变,未发现ＰＭＰ２２基因的点突变。结论Ｃｘ３２、ＭＰＺ和ＰＭＰ２２基因的点突变占ＣＭＴ致病原因的１６．７％。我国也存在不少Ｘ连锁遗传的家系（＞１０．０％）,对可疑的家系（家系中患者无男传男的现象）应首先进行Ｃｘ３２基因的点突变检测。我国的ＣＭＴ发病率低可能与其基因突变特点有关。     

A novel small deletion in PMP22 causes a mild hereditary neuropathy with liability to pressure palsies phenotype

Introduction: In this study we examined a family with electrophysiological findings of hereditary neuropathy with liability to pressure palsies (HNPP) and a mild clinical presentation.Methods: Four members of a family were referred for diagnosis of HNPP. Electrophysiological studies included motor and sensory nerve conduction studies in the upper and lower extremities. Investigations of microsatellites, using polymorphic repeat markers flanking the gene, and multiplex ligation‐dependent probe amplification (MLPA) were performed for molecular studies. Results: The initial study of microsatellites did not detect any change, but MLPA demonstrated a small deletion of exon 5 in the PMP22 gene. Conclusion: Our findings demonstrate the important role of small deletions in the PMP22 gene in the etiology of HNPP with a normal microsatellite study. Muscle Nerve 45: 135–138, 2012     

Coexistent Charcot-Marie-Tooth type 1A and type 2 diabetes mellitus neuropathies in a Chinese family

Charcot-Marie-Tooth disease type 1A(CMT1A) is caused by duplication of the peripheral myelin protein 22(PMP22) gene on chromosome 17. It is the most common inherited demyelinating neuropathy. Type 2 diabetes mellitus is a common metabolic disorder that frequently causes predominantly sensory neuropathy. In this study, we report the occurrence of CMT1 A in a Chinese family affected by type 2 diabetes mellitus. In this family, seven individuals had duplication of the PMP22 gene, although only four had clinical features of polyneuropathy. All CMT1 A patients with a clinical phenotype also presented with type 2 diabetes mellitus. The other three individuals had no signs of CMT1 A or type 2 diabetes mellitus. We believe that there may be a genetic link between these two diseases.