Genotype-Phenotype Correlations In Movement and Neuromuscular Disorders

运动和神经肌肉疾病的基因型-表型相关性

• 批准号: 7594678
• 负责人: Lev G Goldfarb
• 金额: $ 91.55万
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7594678
• 关键词: 11p15; 6p23; Amendment; American; Amino Acids; Atrophic; Axon; Biopsy; Blood specimen; Cardiac; Caucasians; Caucasoid Race; Cells; Chromosome Mapping; Chromosomes; Clinical; Clinical Protocols; Code; Collaborations; Complementary DNA; Cytoplasmic Granules; Defect; Desmin; Diagnostic; Diagnostic Procedure; Disease; Distal; Dorsal; Dystonia; Essential Tremor; Evaluation; Exons; Family; Filament; Genes; Genetic; Genetic Screening; Genetic screening method; Genotype; Greek; Haplotypes; Hereditary Disease; High Pressure Liquid Chromatography; Inclusion Bodies; Informed Consent; Inherited; Laboratories; Link; Location; Lod Score; Malignant hyperpyrexia due to anesthesia; Methodology; Methods; Molecular; Motor; Movement; Muscle; Mutation; Mutation Analysis; Mutation Detection; Myoclonus; Myopathy; N-acylmannosamine kinase; Neurites; Neurodegenerative Disorders; Neuromuscular Diseases; Neurons; Neurosciences; Pathogenesis; Pathogenicity; Patients; Peripheral; Peripheral Nervous System Diseases; Phenotype; Physical Chromosome Mapping; Play; Population; Proteins; RNA analysis; Rate; Research; Role; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sampling; Score; Sensory; Services; Skeletal Muscle; Skeletal system; Tail; Techniques; Tremor; UDP-N-acetylglucosamine 2-epimerase; Variant; alpha Dystroglycan; alpha helix; axonopathy; base; genetic linkage; glycine-tRNA; improved; member; mutant; myotilin; neurogenetics; novel; programs

The Clinical Neurogenetics research program is focused on identification and characterization of genes and genetic mechanisms involved in hereditary movement and neuromuscular disorders. MYOFIBRILLAR MYOPATHIES: We have previously identified desmin gene as the cause of cardiac and skeletal myopathies. To-date, 42 mutations in this gene have been proven pathogenic. The pathogenic potentials correlate with the type and location of desmin mutations: those within the highly conserved 2B helical domain are especially damaging since 2B controls the integrity of the alpha-helix and is responsible for desmin filament assembly and stability. Pathogenic mechanisms of mutations in non-helical carboxy-terminal tail domain that also cause cardiac and skeletal myopathy remain unknown. We have identified and characterized mutations in Myotilin and ZASP, two other genes causing myofibrillar myopathy that is phenotypically distinct from desminopathy. PHENOTYPIC AND FUNCTIONAL ANALYSIS OF GLYCYL-tRNA SYNTHETASE (GARS) MUTATIONS IN dSMA-V/CMT2D TYPE OF PERIPHERAL NEUROPATHY: We have previously identified a gene causing atrophy in thenar and first dorsal interosseus muscles and a clinical continuum of predominantly motor distal neuronopathy/axonopathy with mild to moderate sensory involvement. Functional analyses of disease-associated GARS mutations have shown that the mutant GARS protein mislocalizes in neuronal cells so that endogenous GARS-associated granules are present in the neurite projections. The results suggest that mutant GARS is expressed in peripheral axons and may play a key role in dSMA-V/CMT2D pathogenesis. CHROMOSOMAL MAPPING OF GENES CAUSING ESSENTIAL TREMOR: We have identified, obtained informed consent, clinically evaluated and collected blood samples from members of ten American families with a tremor or tremor/dystonia phenotype. Genetic linkage to a region on chromosome 6p23 was established in two families with a combined NPL-all score 3.125 (P=0.0008), multipoint LOD score 4.248, and maximal two-point LOD score 2.70. Haplotype analysis led to the identification of a 600-kB interval shared by both families. Mutation analysis of coding exons in 14 genes discovered numerous sequence variants, three of which predicted a change of the encoded amino acid. Functional studies with attempts to implicate these genes in ET pathogenesis are under way. A new promising locus on chromosome 11p15 linked to tremor in three other American families suffering of ET is under study. NOVEL HIGHLY EFFICIENT TECHNIQUE FOR MUTATION-DETECTION ANALYSIS OF LARGE GENES. ANALYSIS OF THE RYANODINE RECEPTOR TYPE 1 (RYR1) GENE ASSOCIATED WITH MALIGNANT HYPERTHERMIA: We developed a reliable genetic screening strategy based on Denaturing high-performance liquid chromatography (DHPLC) analysis of RNA samples extracted from the biopsied skeletal muscle followed by cDNA sequencing - as a method of choice for RYR1 mutation detection and identification in patients with Malignant hyperthermia (MH). This methodology significantly increased the mutation-detection rate from 25% to 70% and allowed to identify nine novel RYR1 mutations causing malignant hyperthermia in North-American populations. MUTATIONS IN UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE) GENE CAUSING HEREDITARY INCLUSION BODY MYOPATHY: Mutations in the GNE gene were identified in Caucasian, Indian and Greek families thus expanding the ethnic spectrum of the GNE mutation-associated myopathy. Molecular disease mechanisms involving hypoglycosylation of alpha-dystroglycan are under evaluation.

临床神经遗传学研究计划的重点是识别和表征参与遗传性运动和神经肌肉疾病的基因和遗传机制。 肌纤维性肌病：我们以前已经确定结蛋白基因是心脏和骨骼肌病变的原因。迄今为止，该基因中的42个突变已被证明是致病的。致病潜力与结蛋白突变的类型和位置相关：高度保守的2B螺旋结构域内的那些突变尤其具有破坏性，因为2B控制α-螺旋的完整性，并负责结蛋白丝组装和稳定性。非螺旋羧基末端尾部结构域突变也会导致心脏和骨骼肌病，其致病机制仍不清楚。我们已经确定并表征了肌动素和ZASP的突变，这两个基因引起肌原纤维肌病，其表型不同于结蛋白病。 dSMA-V/CMT 2D型周围神经病中甘氨酰-tRNA还原酶（加尔斯）突变的表型和功能分析：我们先前已经鉴定了一个基因，该基因导致鱼际和第一背侧骨间肌萎缩，临床上主要是运动远端神经元病/轴突病，伴有轻度至中度感觉受累。疾病相关的加尔斯突变的功能分析表明，突变的加尔斯蛋白在神经元细胞中错误定位，使得内源性加尔斯相关颗粒存在于神经突突起中。结果表明，突变的加尔斯在外周轴突中表达，并可能在dSMA-V/CMT 2D发病机制中发挥关键作用。 导致特发性震颤的基因的染色体定位：我们已经确定，获得知情同意，临床评估和收集血液样本，来自10个美国家庭的成员与震颤或震颤/肌张力障碍表型。在两个家庭中建立了与染色体6p 23上的区域的遗传连锁，其合并的NPL-全部得分为3.125（P=0.0008），多点LOD得分为4.248，最大两点LOD得分为2.70。单倍型分析导致两个家庭共享的600 kB的间隔的鉴定。对14个基因编码外显子的突变分析发现了许多序列变异，其中3个预测了编码氨基酸的变化。功能研究，试图牵连这些基因在ET发病机制正在进行中。染色体11 p15上的一个新的有希望的位点与其他三个患有ET的美国家庭的震颤有关，目前正在研究中。 一种新的高效大基因突变检测分析技术与恶性高热相关的兰尼碱受体1型（RYR 1）基因分析：我们开发了一种可靠的遗传筛查策略，该策略基于对从活检骨骼肌中提取的RNA样本进行变性高效液相色谱（DHPLC）分析，然后进行cDNA测序-作为恶性高热（MH）患者RYR 1突变检测和鉴定的首选方法。这种方法显着提高了突变检测率从25%到70%，并允许确定9个新的RYR 1突变导致恶性高热在北美人群。 UDP-N-乙酰葡糖胺-2-差向异构酶/N-乙酰甘露糖胺激酶（GNE）基因突变引起遗传性包涵体肌病：在高加索人、印度人和希腊人家族中鉴定了GNE基因突变，从而扩大了GNE突变相关肌病的种族谱。涉及α-肌营养不良蛋白聚糖低糖基化的分子疾病机制正在评估中。