晚发型甲基丙二酸尿症cblC型家系快速诊断、治疗与随诊

目的总结晚发型甲基丙二酸尿症cblC型两家系4例患儿临床表型、治疗原则及预后,探讨其病理生理学机制。方法与结果采用外显子组测序技术快速诊断晚发型甲基丙二酸尿症cblC型两家系。家系1姊妹存在MMACHC基因外显子4 c.482G A(p.Arg161Gln)和c.615C A(p.Tyr205X)复合杂合突变,分别来自其父母。先证者主要表现为智力减退、下肢痉挛性运动障碍伴癫发作;其妹则呈现以轴索损害为主的四肢周围神经病变和视神经萎缩,而智力减退症状相对较轻。家系2兄妹存在MMACHC基因外显子4 c.440_441del(p.Gly147fs)和c.482GA(p.Arg161Gln)复合杂合突变,分别来自其父母。先证者表现为智力减退、精神行为异常和双下肢无力伴锥体束征,呈髓鞘和轴索混合性损害的周围神经病变;其妹症状相似但发病年龄较早。采用维生素B12、叶酸、左卡尼汀等药物联合治疗6个月患儿智力水平明显提高、癫发作得以控制,但均遗留不同程度双下肢运动障碍。结论晚发型甲基丙二酸尿症cblC型临床表现复杂多样,可广泛累及大脑皮质、锥体束、锥体外系、周围神经等,目标区域捕获联合第二代测序技术可以快速明确诊断,早期诊断、积极治疗对改善患者预后至关重要。     

晚发型甲基丙二酸尿症合并同型半胱氨酸血症临床及分子遗传学特点研究

目的分析1例晚发型甲基丙二酸尿症合并同型半胱氨酸血症家系的临床及分子遗传学特点并对相关文献进行复习。方法采用Sanger测序对收集的1例以精神症状为首发症状的该病家系进行MMACHC基因突变的检测并总结分析相关文献。结果测序发现先证者MMACHC基因2号外显子的1个新错义突变(c.160AC)和4号外显子的一个已知错义突变(c.482GA)。通过文献复习提示,在该病中临床症状以认知障碍和精神行为异常最常见,MMACHC基因突变以c.609GA和c.271dup A最常见。结论 MMACHC基因的c.160AC和c.482GA复合杂合突变是本例患者的病因,MMACHC基因在该病具有致病作用;该疾病属于罕见疾病,临床异质性很高,临床上容易漏诊误诊,当出现不明原因的精神行为异常时宜考虑该诊断。     

晚发型cblC型甲基丙二酸尿症合并同型半胱氨酸血症1例报告并文献复习

目的 探讨晚发型甲基丙二酸尿症合并同型半胱氨酸血症的临床及基因变异特点。方法 回顾性分析1例MMACHC基因突变致晚发型cblC型甲基丙二酸尿症合并同型半胱氨酸血症患者的临床资料及基因检测结果，并结合文献讨论。结果 本例男性患者，以双足麻木起病，逐渐出现双下肢僵硬无力，发病前有非特异性精神行为异常症状，此次就诊经基因检测发现MMACHC基因4号外显子存在c. 482G>A(p. Arg161Gln)错义突变，与文献报道c. 482G>A复合杂合突变不同，本例患者突变类型为纯合突变。结论 甲基丙二酸尿症合并同型半胱氨酸血症的临床异质性较大，容易漏诊误诊，当出现不明原因的精神行为异常时应考虑该诊断，基因检测是诊断的重要依据，同时也可指导该病的分型。     

MTMR13/SBF2基因复合杂合突变致腓骨肌萎缩症4B2型一家系临床表型及基因突变分析

目的探讨腓骨肌萎缩症4B2型(CMT4B2型)的临床表型和分子遗传学特征。方法一家系3例CMT4B2型患儿,采用目标区域捕获测序技术检测MTMR13/SBF2基因突变类型。结果例1(先证者)6年前出现双下肢无力,行走向前跨步,跑步速度较同班同学明显缓慢,随后症状逐渐加重,出现双手大小鱼际肌和骨间肌萎缩,双侧指关节不能伸直,双侧小腿肌萎缩,双侧马蹄内翻足和四肢腱反射减弱。例2(先证者之大弟)2年前出现双下肢无力,行走不稳,跑步和上楼梯较前明显缓慢,步态异常逐渐加重,足跟行走不能,双手大小鱼际肌萎缩,双侧小腿轻度肌萎缩,四肢腱反射减弱。例3(先证者之二弟)足跟行走困难,双手大小鱼际肌轻度肌萎缩,四肢腱反射减弱。基因检测显示,例1存在MTMR13/SBF2基因c.230GA(p.Gln77Arg)和c.1537CT(p.Gln513~*)复合杂合突变,其父携带c.230GA(p.Gln77Arg)杂合突变,其母携带c.1537CT(p.Gln513~*)杂合突变,例2和例3均存在与先证者相同的c.230GA(p.Gln77Arg)和c.1537CT(p.Gln513~*)复合杂合突变。3例患儿诊断明确为CMT4B2型,该家系明确诊断为CMT4B2型家系。予甲钴胺对症治疗,先证者马蹄内翻足明显,予石膏固定疗法予以纠正。结论 CMT4B2型是罕见且严重的进展型腓骨肌萎缩症,目前尚无有效治疗方法,对患者进行及时的基因检测以明确诊断,同时对患病家系积极开展遗传咨询,对于有生育要求的致病基因携带者还应结合产前基因诊断以避免患病胎儿的出生。对于家系中携带致病基因尚未出现临床症状或处于疾病早期的患者,应密切随访,采取积极治疗以尽可能延迟发病时间或指导患者进行正确的康复训练以预防弓形足、脊柱侧弯等畸形,从而提高生活质量。     

甲基丙二酸血症合并高同型半胱氨酸血症的临床特点(附1例报告)

目的 探讨甲基丙二酸血症(MMA)合并高同型半胱氨酸血症的临床特点.方法 回顾性分析1例MMA合并高同型半胱氨酸血症患者的临床资料,并进行复习文献.结果 患者女性,30岁,临床表现为双下肢麻木无力.尿甲基丙二酸、血丙酰基肉碱与乙酰基肉碱的比值(C3/C2)、血同型半胱氨酸均升高;基因检测发现MMACHC基因存在c.60...     

脂肪酸羟化酶相关性神经变性病四例临床表型及基因突变分析

目的报道4例脂肪酸羟化酶相关性神经变性病患者,并复习相关文献,总结该病临床表型和基因突变特点。方法收集4例脂肪酸羟化酶相关性神经变性病患者临床资料和家系资料,标准酚氯仿法提取患者及其父母基因组DNA并行Sanger测序。结果 4例患者中3例(例2、例3和例4)具有典型脂肪酸羟化酶相关性神经变性病表现,1例(例1)表现为非典型。FA2H基因检测显示,4例患者均存在FA2H基因突变,其中例1为复合杂合突变c.461GA(p.Arg154His)和c.794TG(p.Phe265Cys);例2仅发现1种已报道的杂合突变c.703CT(p.Arg235Cys),进一步对例2及其母进行单核苷酸多态性检测,亦未发现缺失突变;例3为杂合突变c.688GA(p.Glu230Lys)和插入突变c.172_173ins GGGCCAGGAC(p.Ile58Argfs X47);例4为复合杂合突变c.688GA(p.Glu230Lys)、c.968CA(p.Pro323Gln)和c.976GA(p.Gly326Asp),其父为c.688GA(p.Glu230Lys)突变携带者,其母为c.968CA(p.Pro323Gln)和c.976GA(p.Gly326Asp)突变携带者。根据美国医学遗传学和基因组学会标准,例1的FA2H基因杂合突变c.461GA(p.Arg154His)为"可能致病"、c.794TG(p.Phe265Cys)为"可能致病";例2的FA2H基因杂合突变c.703CT(p.Arg235Cys)为"可能致病";例3的FA2H基因杂合突变c.688GA(p.Glu230Lys)为"致病"、插入突变c.172_173ins GGGCCAGGAC(p.Ile58Argfs X47)为"致病";例4的FA2H基因杂合突变c.688GA(p.Glu230Lys)为"致病"、c.968CA(p.Pro323Gln)为"致病"、c.976GA(p.Gly326Asp)为"可能致病"。结论脂肪酸羟化酶相关性神经变性病具有高度临床和遗传异质性,痉挛性截瘫是最主要的临床表现,对于复杂型常染色体隐性遗传性遗传性痉挛性截瘫,尤其合并构音障碍、智力减退、脑白质病变和小脑萎缩等临床特征的患者,应考虑FA2H基因突变导致的脂肪酸羟化酶相关性神经变性病。     

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。     

中国华东地区家族性肌萎缩侧索硬化症患者SOD1基因突变检测及临床特点分析

目的对中国华东地区26例临床确诊为家族性肌萎缩侧索硬化症(FALS)家系的先证者进行铜锌超氧化物歧化酶(SOD1)的基因突变筛查。方法收集26例FALS家系先证者的外周血样本及临床资料。采用PCR技术结合DNA直接测序法对外周血DNA进行SOD1基因5个外显子的突变筛查,并分析SOD1基因突变与临床表型的关系。结果有6例先证者检测出3种SOD1突变。其中3例为位于2号外显子的已知错义突变p.His46Arg(c.140AG),均表现为单侧下肢远端起病,上运动神经元损害不明显,平均病程可达10年以上。2例为位于2号外显子的已知错义突变p.Val47Ala(c.143TC),临床表型较复杂,病变进展相对较快。1例为位于2号外显子新的错义突变p.Gly37Arg(c.112GC),单侧上肢远端起病,上下运动神经元均受损,进展缓慢。结论中国华东地区FALS患者中SOD1基因突变仍占首位,突变与临床表型相关,其中His46Arg的临床表型具有特征性,有助于疾病预后判断。     

正常血钾型周期性麻痹SCN4A基因新突变的检测

目的　报道正常血钾型周期性麻痹 (normoPP)一家系的临床特点 ,并筛查SCN4A基因以期发现有义突变。方法　提取知情同意的患者及部分家属外周血基因组DNA ,应用变性高效液相色谱分析 (DHPLC)技术筛查患者SCN4A基因全部 2 4个外显子 ,对发现异常者进行测序分析。结果先证者常规实验室检查未见异常 ,发作期肌酸激酶 (CK) 112 6U/L(正常值 <2 0 0U/L) ,肌电图正常。发作间期行肌肉活检未见显著异常。基因研究发现先证者及其父亲 (患者 )SCN4A基因发生同一新突变G2 10 1A ,并引起氨基酸序列改变Arg6 75Gln。该突变不同于目前发现的明确导致高钾型周期性麻痹(hyperPP)的突变 ,也不同于已知的SCN4A基因所有突变。结论　normoPP患者存在一新突变Arg6 75Gln ,该突变可能与疾病相关。     

短链脂酰辅酶A脱氢酶缺陷综合征一家系临床表型及基因突变分析

目的总结短链脂酰辅酶A脱氢酶缺陷综合征临床表型和基因突变特点。方法与结果女婴患儿,1个月14 d,临床表现为智力和运动发育迟滞、肌张力下降、癫发作,发作类型为痉挛发作和全面性强直发作;体格检查可见左侧面部和左上腹部咖啡牛奶斑;尿液乙基丙二酸、甲基琥珀酸和全血丁酰肉碱水平升高;发作间期视频脑电图可见爆发-抑制波形;头部MRI显示,左侧大脑半球和右侧额叶皮质发育畸形;基因检测显示,患儿存在ACADS基因c.795+1GA纯合突变,分别来自携带该位点杂合突变的父母。患儿明确诊断为短链脂酰辅酶A脱氢酶缺陷综合征,该家系明确诊断为短链脂酰辅酶A脱氢酶缺陷综合征家系。在服用泼尼松4 mg/(kg·d)和左乙拉西坦30 mg/(kg·d)基础上,增加维生素B210 mg/(kg·d)口服。随访至今,未再出现癫发作。结论短链脂酰辅酶A脱氢酶缺陷综合征临床表现为智力和运动发育迟滞、肌张力下降和早发性癫性脑病,尿液乙基丙二酸、甲基琥珀酸和全血丁酰肉碱升高,并可能导致皮质发育畸形。ACADS基因c.795+1GA纯合突变可以致病,为首次报道。     

肢带型肌营养不良症2D型一家系临床表型及基因突变分析

目的总结肢带型肌营养不良症2D型(LGMD2D型)临床表型和基因突变特点。方法报道一家系2例女性LGMD2D型患儿临床表现、肌电图、肌肉MRI、肌肉病理学和基因检测结果,并结合相关文献进行分析。结果先证者及其妹均于3岁发病,以进行性四肢近端无力为主要临床表现;血清肌酸激酶水平显著升高;肌电图呈肌源性损害;肌肉MRI显示部分肌肉萎缩、脂肪化或纤维水肿;其妹肌肉病理学显示局灶性骨骼肌坏死、再生,部分横纹肌消失,肌纤维大小不等。基因检测显示,先证者及其妹存在相同基因突变,即SGCA基因第3外显子移码突变c.262del T(p.Phe88SerfsX123)和第5外显子错义突变c.409GA(p.Glu137Lys),其母为SGCA基因c.409GA(p.Glu137Lys)突变携带者,其中,c.409GA(p.Glu137Lys)为已知突变,c.262del T(p.Phe88SerfxX123)为新发突变。结论对于临床类似Duchenne型肌营养不良症的女性患者,排除DMD基因携带者后,还应行家系分析和肢带型肌营养不良症相关基因检测,以明确具体亚型。     

以小脑损害为主要表现的成人甲基丙二酸血症合并高同型半胱氨酸血症一例

报告1例成年起病的甲基丙二酸血症合并高同型半胱氨酸血症患者的临床资料。患者为男性,24岁发病,以行走不稳、精神行为异常起病,进行性加重,神经系统体检发现明显的小脑性共济失调及锥体束征,头颅磁共振成像显示双侧小脑半球对称性长T2信号,血液总同型半胱氨酸、尿甲基丙二酸水平显著增高,基因检测发现MMACHC基因复合杂合突变c.482G>A及c.217C>T,确诊为钴胺素C缺乏症。经给予腺苷钴胺、甜菜碱、叶酸、左卡尼汀治疗后患者行走不稳略有所好转,血同型半胱氨酸水平也显著下降。     

Interaction of heritable and estrogen-induced thrombophilia: possible etiologies for ischemic optic neuropathy and ischemic stroke

Our specific aim was to assess how thrombophilic exogenous estrogens interacted with heritable thrombophilias leading to non-arteritic ischemic optic neuropathy (NAION) and ischemic stroke. Coagulation measures were performed in a 74 year old patient and her immediate family. The proband had a 47 year history of 9 previous thrombotic episodes, and developed unilateral NAION 4 years after starting estrogen replacement therapy (ERT). The proband was heterozygous for two thrombophilic gene mutations (G20210A prothrombin gene, platelet glycoprotein IIIa P1A1/A2 polymorphism), and homozygous for the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene. Of 238 normal controls, none had these 3 gene mutations together. The proband's mother and brother had deep venous thrombosis (DVT). The proband's brother, sister, nephew, daughter, and two granddaughters were homozygous for the C677T MTHFR mutation. The proband's brother was heterozygous for the G20210A prothrombin gene mutation. The proband's niece was heterozygous for the G20210A prothrombin gene mutation, homozygous for the C677T MTHFR mutation, homozygous for the hypofibrinolytic 4G polymorphism of the plasminogen activator inhibitor-1 (PAI-1) gene, and heterozygous for the platelet glycoprotein IIIa P1A1/A2 polymorphism. Of 238 normal controls, none had the niece's combination of 4 gene mutations. When ERT-mediated thrombophilia was superimposed on the proband's heritable thrombophilias, unilateral ischemic optic neuropathy developed, her tenth thrombotic event over a 5 decade period. When estrogen-progestin oral contraceptives were given to the proband's niece, she had an ischemic stroke at age 22. Exogenous estrogen-mediated thrombophilia superimposed on heritable thrombophilia and hypofibrinolysis is associated with arterial and venous thrombi, and appears to be a preventable, and potentially reversible etiology for ischemic optic neuropathy and ischemic stroke.     

Increased plasma homocysteine levels without signs of vitamin B12 deficiency in patients with multiple sclerosis assessed by blood and cerebrospinal fluid homocysteine and methylmalonic acid

OBJECTIVE: The aim of this study was to evaluate if multiple sclerosis (MS) is associated with vitamin B12 (cobalamin) deficiency. METHODS: We measured serum vitamin B12, plasma folate, serum methylmalonic acid (MMA), plasma homocysteine (tHcy) and also cerebrospinal fluid (CSF) MMA and tHcy in 72 patients with MS and 23 controls. RESULTS: The mean plasma tHcy level was significantly increased in MS patients (11.6 micromol/L) compared with controls (7.4 micromol/L) (P = 0.002). Seven patients showed low serum vitamin B12 levels but only one of them had concomitant high plasma tHcy. None of them showed high serum MMA. Plasma or blood folate levels did not differ between MS patients and controls. We found no significant differences in mean values or frequency of pathological tests of serum B12, serum MMA, mean corpuscular volume (MCV), haemoglobin concentration, CSF tHcy or CSF MMA between patients and healthy subjects. There were no correlations between CSF and serum/plasma levels of MMA or tHcy. Serum vitamin B12, serum MMA, plasma tHcy, CSF Hcy or CSF MMA were not correlated to disability status, activity of disease, duration of disease or age. CONCLUSIONS: The relevance of the increased mean value of plasma tHcy thus seems uncertain and does not indicate functional vitamin B12 deficiency. We can not, however, exclude the possibility of a genetically induced dysfunction of the homocysteine metabolism relevant for the development of neuroinflammation/degeneration. Our findings indicate that, regardless of a significant increase in plasma tHcy in MS patients, the MS disease is not generally associated with vitamin B12 deficiency since we did not find any other factors indicating vitamin B12 deficiency. Analysis of CSF MMA and CSF tHcy, which probably reflects the brain vitamin B12 status better than serum, are not warranted in MS. We conclude that B12 deficiency, in general, is not associated with MS.     

Novel heteroplasmic mtDNA mutation in a family with heterogeneous clinical presentations.

The protean manifestations of a novel maternally inherited point mutation of the mitochondrial genome are reported. The proband showed isolated, spastic paraparesis. A brother, who had suffered from a multisystem progressive disorder, ultimately died of cardiomyopathy. Another brother is healthy. The proband's mother showed truncal ataxia, dysarthria, severe hearing loss, mental regression, ptosis, ophthalmoparesis, distal cyclones, and diabetes mellitus. A muscle biopsy performed in the proband failed to show the morphological abnormalities typical of mitochondrial disorders; the activities of respiratory chain complexes were normal. However, complex I and IV activities were low in the muscle homogenate of the affected mother and brother. Sequence analysis of mtDNA showed a heteroplasmic mutation of the tRNA(Ile) gene (G4284A). The mutation load was approximately 55%, 80%, and 90% in the muscle mtDNA of the proband, his mother, and his affected brother, respectively. Mutation was undetected in the healthy brother, as well as in 100 control samples. Several cybrid clones containing homoplasmic mutant mtDNA from the proband showed significant reductions of complex IV activity and maximum oxygen consumption rate, compared with homoplasmic wild-type clones derived from the same subject.     

目标区域捕获测序检测常染色体隐性遗传性腓骨肌萎缩症GDAP1基因突变

研究背景腓骨肌萎缩症存在高度临床和遗传异质性,传统基因检测需对众多候选基因逐一筛查,存在效率低、耗时、费力等局限性。本文旨在探讨目标区域捕获测序技术诊断常染色体隐性遗传性腓骨肌萎缩症的可行性。方法采集5例临床拟诊常染色体隐性遗传性腓骨肌萎缩症患者的临床资料和外周血样本,采用目标区域捕获测序技术筛查腓骨肌萎缩症相关基因突变,Sanger测序对候选变异位点在患者及其父母外周血样本中进行验证。结果目标区域捕获测序显示,2例检出GDAP1基因复合杂合突变,余3例未检出致病性突变。经Sanger测序证实2例患儿存在GDAP1基因突变,例1为GDAP1基因复合杂合突变c.767AG(p.His256Arg)和c.866TA(p.Phe289Tyr),其父携带c.866TA(p.Phe289Tyr)突变,其母携带c.767AG(p.His256Arg)突变;例2为GDAP1基因复合杂合突变c.571CT(p.Arg191X)和c.589del C(p.Asp198IlefsX8),其父携带c.589del C(p.Asp198IlefsX8)突变,其母携带c.571CT(p.Arg191X)突变,最终明确诊断为常染色体隐性遗传性腓骨肌萎缩症。结论目标区域捕获测序技术是一项高效基因检测方法,适用于常染色体隐性遗传性腓骨肌萎缩症的基因诊断。     

DMD Trp3X nonsense mutation associated with a founder effect in North American families with mild Becker muscular dystrophy

A recurrent exon 1 nonsense mutation in the DMD gene, p.Trp3X (c.9G > A), was first ascertained in a proband with no symptoms until age 20 and who walked until the age of 62. Six other unrelated kindreds carrying a p.Trp3X mutation were subsequently ascertained, five from North America and one from Italy. In six of the seven kindreds, the proband presented in childhood incidental to elevated creatine kinase levels detected in the context of other illnesses, or in the setting of cramps with or without rhabdomyolysis. Genetic analysis by high density SNP genotyping demonstrates that the six North American families share a 3.7 Mbp haplotype surrounding the p.Trp3X allele, signifying that this is a founder mutation in these individuals. The size of the founder haplotype and the structure of shared genome-wide segments suggests that the minimal age of this mutation is >6 generations. The discovery of the first DMD founder mutation, associated with a mild Becker phenotype, suggests that the prevalence of hypomorphic dystrophin mutations should be re-examined with the use of improved genomic analysis.     

头部震颤伴小脑萎缩一例临床表型及基因突变分析

目的通过对1例头部震颤伴小脑萎缩患者临床表型和基因检测结果进行综合分析,明确诊断疾病并探讨基因检测结果的解读方法。方法与结果采集1例30岁男性患者临床表型,进行二代基因测序和Sanger测序验证,通过中文人类表型标准用语、基因检索工具Phenomizer、Ensembl数据库、在线人类孟德尔遗传数据库相关信息,对基因检测结果进行解读。结果显示,患者存在脊髓小脑共济失调19型(SCA19型)致病基因KCND3基因杂合突变c.1057AG(p.Ser353Gly),其父母均未携带该突变基因;患者还存在帕金森病20型致病基因SYNJ1基因杂合突变c.4436CT(p.Thr1479Ile),其母携带该突变基因。表型相似度分析显示,患者表型与SCA19型一致,KCND3基因变异位点c.1057AG在不同物种同源基因中具有高度保守性。结论通过对患者临床表型和基因检测结果综合分析,KCND3基因杂合突变c.1057AG(p.Ser353Gly)为致病性突变。