心律失常的基因诊断

遗传性心律失常综合征往往南基因突变引起,而这些异常基因主要为编码心脏离子通道蛋白的基因，因而这类疾病也被称为离子通道病;其他还包括编码细胞骨架蛋白、细胞间连接蛋白等的基因。基因诊断即利用现代分子生物学和分子遗传学的技术方法，     

WAS综合征患者硬膜下腔血肿清除术后行单倍体异基因骨髓移植1例护理

正Wiskott-Aldrich综合征(Wiskott-Aldrich Syndrome,WAS)又称湿疹、血小板减少伴免疫缺陷综合征,属于X连锁隐性遗传性疾病,发病率为百万分之一至百万分之十,以湿疹、血小板减少伴血小板体积减小、反复感染、易患自身免疫性疾病及淋巴系统恶性肿瘤为特征[1]。WAS基因突变所致的WAS蛋白缺失或结构异常可导致多样化的临床表现及免疫学改变[2]。WAS患者预后往往较差,激素及免疫抑制剂对WAS合并自身免     

MYH9异常的实验室和临床诊断策略

肌球蛋白重链9 (MYH9)异常是一组由MYH9基因突变引起的遗传性血小板减少症,包括May-Hegglin异常、Epstein综合征、Fechtner综合征和Sebastian综合征.MYH9异常常被误诊为原发性血小板减少性紫癜.本文对其发病机制、临床体征、实验室检查和鉴别诊断进行阐述,以进一步加深临床和实验室对MYH9的认识,同时引起临床的足够重视.     

遗传性疾病的基因诊断

分子生物学理论和技术的飞速发展、人类基因组计划的突破性成就,为人们认识和诊断遗传性疾病提供了有效的手段[1].通过研究遗传性疾病的致病基因DNA结构以及转录或翻译水平的异常,已初步揭示了其中部分疾病的分子遗传学基础,成为临床疾病诊断和分类的重要依据.分子生物学中具有独创性和革命性的新方法、新技术的问世及其向医学领域的渗透,使遗传性疾病的基因诊断逐渐走出研究部门的实验室,转化为常规的临床检查项目,成为临床医学的一个重要组成部分.     

遗传性疾病的基因诊断

分子生物学理论和技术的飞速发展、人类基因组计划的突破性成就 ,为人们认识和诊断遗传性疾病提供了有效的手段 [1]。通过研究遗传性疾病的致病基因 DNA结构以及转录或翻译水平的异常 ,已初步揭示了其中部分疾病的分子遗传学基础 ,成为临床疾病诊断和分类的重要依据。分子生物学中具有独创性和革命性的新方法、新技术的问世及其向医学领域的渗透 ,使遗传性疾病的基因诊断逐渐走出研究部门的实验室 ,转化为常规的临床检查项目 ,成为临床医学的一个重要组成部分。一、遗传性疾病的各种基因异常遗传性疾病的产生是由于一个 (或数个 )基因发生…     

遗传性疾病基因诊断的基本原理

用分子生物学技术通过检测基因而达到诊断疾病的目的是生物学者在分子生物学技术发展的最初阶段就有的设想。１９７６年人们开始在实验室进行研究，１９８４年以来，基因检测在许多国家已成为常规诊断项目，主要用于遗传性疾病的诊断。１基因突变的种类遗传性疾病的产生是由于１个基因或数个基因发生异常导致这些基因所载有的遗传信息改变，继而使蛋白质合成受影响；或是合成有缺陷的蛋白质（功能和结构的改变），或是无蛋白质合成。基因异常有多种多样，它们都被称为突变。突变范围大小不一，最小仅涉及１个碱基，称为点突变。而大范围的突…     

福建省非综合征型耳聋患者常见致病基因的突变分析

我国听力残疾人群有2780万,居各类人群之首(33％)[1].耳聋可以由单一基因突变或不同基因的复合突变引起,也可由环境因素或基因与环境两者共同作用而致.50％的儿童发病原因不明,其余50％为遗传性耳聋.在遗传性耳聋中,30％为综合性耳聋,70％为不伴有其他症状和体征的非综合征型耳聋(non-syndromic hearing loss,NSHL)[2].迄今为止,与NSHL相关的致病基因至少有68个已经被克隆和定位[3-4],每个基因中有1个或多个突变位点,具有较高的基因和位点遗传异质性.尽管已经明确,我国相当一部分NSHL仅由为数不多的几个基因突变引起[5-8],包括GJB2、GJB3、SLC26 A4及mtDNA 12S rRNA等,但在不同地区,由于环境、种族、婚配、遗传方式等差异,聋哑人群耳聋基因突变谱将有所差异.本研究采用基因芯片技术调查福建省某聋哑学校NSHL学生致病原因,并与传统基因诊断方法包括酶切、直接测序方法进行比较,以评价不同的实验方法在耳聋基因诊断中的价值和应用.     

新一代测序技术在遗传性血小板病基因诊断中的应用

遗传性血小板病是一组表现为血小板数量和功能异常,并可累及血液以外系统的异质性遗传病。遗传性血小板病的临床异质性以及广泛分布的致病基因对其诊断与治疗造成巨大挑战。目前临床上获得明确分子诊断的遗传性血小板病患者只占小部分,并且在已知致病基因以外仍然存在有大量未知遗传变异。新一代测序技术的普及推动了个体化基因检测的发展。很多研究者已经运用全基因组测序、全外显子组测序和靶向基因测序等手段在血栓与止血领域取得了不少新进展。临床上新一代测序的开展不仅促进了遗传性血小板病的个体化基因诊断,而且为未来的精准化基因治疗奠定了基础。本文就用新一代测序技术诊断血小板相关疾病取得的新进展作一综述。     

基因源性心脏病——Brugada综合征的研究现状

基因源性心脏病,又称遗传性心律失常综合征[1],包括Brugada综合征(Brugada syndrome,BS)、遗传性长QT综合征(LQTS)、家族性预激综合征(WPW)、致心律失常性右室心肌病(ARVC)、儿茶酚胺敏感性多形性室性心动过速(CPVT)、Lene-gre-Lev病等,大多是由于编码心肌离子通道基因突变引起离子通道功能异常而导致的一组常染色体显性遗传病。其中,BS是由Brugada兄弟于1992年首次报道的原发性心电疾病,临床上以V1～V3ST段抬高及多变、反复发作多形性室速或室颤和晕厥,以及心脏性猝死为特征。     

分子生物技术在神经系统疾病中的应用

本介绍了PCR技术、RFLP技术及基因诊断和基因治疗技术在神经系统疾病，尤其是神经系统遗传性疾病方面应用进展。     

Inherited thrombocytopenias frequently diagnosed in adults

The diagnosis of inherited thrombocytopenias is difficult, for many reasons. First, as they are all rare diseases, they are little known by clinicians, who therefore tend to suspect the most common forms. Second, making a definite diagnosis often requires complex laboratory techniques that are available in only a few centers. Finally, half of the patients have forms that have not yet been described. As a consequence, many patients with inherited thrombocytopenias are misdiagnosed with immune thrombocytopenia, and are at risk of receiving futile treatments. Misdiagnosis is particularly frequent in patients whose low platelet count is discovered in adult life, because, in these cases, even the inherited origin of thrombocytopenia may be missed. Making the correct diagnosis promptly is important, as we recently learned that some forms of inherited thrombocytopenia predispose to other illnesses, such as leukemia or kidney failure, and affected subjects therefore require close surveillance and, if necessary, prompt treatments. Moreover, medical treatment can increase platelet counts in specific disorders, and affected subjects can therefore receive drugs instead of platelet transfusions when selective surgery is required. In this review, we will discuss how to suspect, diagnose and manage inherited thrombocytopenias, with particular attention to the forms that frequently present in adults. Moreover, we describe four recently identified disorders that belong to this group of disorders that are often diagnosed in adults: MYH9‐related disease, monoallelic Bernard–Soulier syndrome, ANKRD26‐related thrombocytopenia, and familial platelet disorder with predisposition to acute leukemia.     

Qualitative disorders of platelets and megakaryocytes

Qualitative disorders of platelet function and production form a large group of rare diseases which cover a multitude of genetic defects that by and large have as a common symptom, excessive mucocutaneous bleeding. Glanzmann thrombasthenia, is enabling us to learn much about the pathophysiology of integrins and of how alphaIIb beta3 functions. Bernard-Soulier syndrome, an example of macrothrombocytopenia, combines the production of large platelets with a deficit or non-functioning of the major adhesion receptor of platelets, the GPIb-IX-V complex. Amino acid substitutions in GPIb alpha, may lead to up-regulation and spontaneous binding of von Willebrand factor as in Platelet-type von Willebrand disease. In disorders with defects in the MYH9 gene, macrothrombocytopenias are linked to modifications in kidney, eye or ear, whereas other inherited thrombocytopenias variously link a low platelet count with a propensity to leukemia, skeletal defects, learning impairment, and abnormal red cells. Defects of secretion from platelets include an abnormal alpha-granule formation as in the gray platelet syndrome (with marrow myelofibrosis), and of organelle biogenesis in the Hermansky-Pudlak and Chediak-Higashi syndromes where platelet dense body defects are linked to abnormalities of other lysosomal-like organelles including melanosomes. Finally, defects involving surface receptors (P2Y(12), TPalpha) for activating stimuli, of proteins essential for signaling pathways (including Wiskott-Aldrich syndrome), and of platelet-derived procoagulant activity (Scott syndrome) show how studies on platelet disorders are helping unravel the pathways of primary hemostasis.     

Inherited platelet disorders

Inherited platelet disorders are a rare, but probably underdiagnosed, cause of symptomatic bleeding. They are characterized by abnormalities of platelet number (inherited thrombocytopenias), function (inherited disorders of platelet function) or both. This review briefly discusses the inherited platelet disorders with respect to molecular defects, diagnostic evaluation and treatment strategies.     

Inherited amino acid transport disorders]

Disorders due to inherited amino acids transport defect are reviewed. The disorders were categorized into three types of transport defects, namely, brush-border membrane of epithelial cells of small intestine and kidney tubules (Hartnup disease, blue diaper syndrome, cystinuria, iminoglycinuria and lysine malabsorption syndrome), basolateral membrane (lysinuric protein intolerance) and membrane of intracellular organelles (cystinosis and hyperornitinemia-hyperammonemia-homocitrullinuria syndrome). Pathogenesis, clinical feature, laboratory findings, diagnosis, genetics and treatment of these disorders are described, briefly. There is not much data for the transport systems themselves, so that further investigation in molecular and gene levels for transport systems is necessary to clarify the characteristics of the transport and heterogeneity of phenotypes in inherited amino acids transport disorders.     

遗传性血小板减少症的诊断

遗传性血小板减少症是一类以血小板减少为特征的罕见疾病。近几十年来,尽管该疾病的分子发病基础研究取得了显著进展,如发现大部分患者存在异常表达的基因,然而,其病理生理机制目前仍不十分清楚,诊断也较为困难。本文结合文献和我们的实践经验,对遗传性血小板减少症的分类、临床表现以及实验室血小板计数和形态学的特点作一综述,以助于提高临床医师和检验医师对该类疾病的诊断。     

MYH-9 Related Platelet Disorders: Strategies for Management and Diagnosis

MYH-9 related platelet disorders belong to the group of inherited giant platelet disorders. The MYH-9 gene encodes the non-muscular myosin heavy chain IIA (NMMHCIIA), a cytoskeletal contractile protein. Several mutations in the MYH-9 gene lead to macrothrombocytopenia, and cytoplasmic inclusion bodies within leukocytes, while the number of megakaryocytes in the bone marrow is normal. Four overlapping syndromes, known as May-Hegglin anomaly, Epstein syndrome, Fechtner syndrome and Sebastian platelet syndrome, describe different clinical manifestations of MYH9 gene mutations. Macrothrombocytopenia is present in all affected individuals, whereas only some develop additional clinical manifestations such as renal failure, hearing loss and presenile cataracts. The bleeding tendency is usually moderate, with menorrhagia and easy bruising being most frequent. The biggest risk for the individual is inappropriate treatment due to misdiagnosis of chronic autoimmune thrombocytopenia. More than 30 mutations within the 40 exons of the MYH-9 gene leading to macrothrombocytopenia have been identified, of which the upstream mutations up to amino acid ~1400 are more likely associated with syndromic manifestations than the downstream mutations. Diagnosis is based on identification of the granulocyte inclusion bodies using blood smears and immunofluorescence and is finally confirmed by identifying the mutation. Treatment is supportive and should be aimed to prevent iron deficiency anemia. Beside renal failure, the biggest risk for patients affected by a MYH-9 disorder are the adverse effects resulting form treatment based on the misdiagnosis of immune thrombocytopenia.     

Congenital and acquired platelet function disorders

A survey is given on congenital and acquired platelet functional disorders. Congenital platelet functional disorders are extremely rare. Acquired platelet functional disorders are probably the most frequent disturbances of haemostasis. The knowledge of the defects leading to inherited platelet function disorders much improved our understanding of platelet function in general. Acquired platelet functional disorders are due to various diseases and drugs.     

Gene therapy for platelet disorders: studies with Glanzmann's thrombasthenia

Summary. Current research aimed at correcting platelet defects are designed to further our knowledge in the use of hematopoietic stem cells for gene therapies of hemorrhagic disorders. Information gained from these studies may be directly applicable to treatment of disorders affecting platelets (e.g. Glanzmann's thrombasthenia, Bernard Soulier syndrome, gray platelet syndrome, and von Willebrand disease) as well as other disorders affecting distinct hematopoietic cell lineages. This work specifically addresses three questions: (i) can bone marrow stem cells be given sufficient genetic information to induce abnormal megakaryocytes to synthesize transgene products that help newly formed platelets to participate in normal hemostasis? (ii) can the newly synthesized receptor be maintained as a platelet‐specific protein at therapeutic levels for a reasonable period of time? and (iii) will newly expressed proteins be tolerated by the immune system or become a target for B‐ and T‐cell mediated immunity resulting in the premature destruction and clearing of the genetically altered megakaryocytes and platelets? Answers to these questions should indicate the feasibility of targeting platelets with genetic therapies that will in turn enable better management of patients with inherited bleeding disorders. The long‐range benefit of this research will be an improved understanding of the regulation of protein expression during normal megakaryocytopoiesis, and the accumulation of additional scientific knowledge about normal platelet function and the way in which platelets and other cells recognize and interact with each other.     

Clinical and biochemical landmarks in systemic autoinflammatory diseases

Abstract

Systemic autoinflammatory diseases are a group of inherited disorders of the innate immune system characterized by seemingly unprovoked inflammation recurring at variable intervals and involving skin, serosal membranes, joints, and gastrointestinal apparatus, with reactive amyloidosis as a possible severe long-term complication. Recent advances in genetics and molecular biology have improved our understanding of the pathogenesis of these diseases, including familial Mediterranean fever, mevalonate kinase deficiency syndrome, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndromes, and hereditary pyogenic and granulomatous disorders: the vast majority of these conditions are related to the activation of the interleukin-1 pathway, which results in (or from?) a common unifying pathogenetic mechanism. Their diagnostic identification derives from the combination of clinical data, evaluation of acute phase reactants, clinical efficacy in response to specific drugs, and recognition of specific mutations in the relevant genes, although genetic tests may be unconstructive in some cases. This review will discuss clinical and laboratory clues useful for a diagnostic approach to systemic autoinflammatory diseases.     

Genetic analysis and immunophenotyping in the diagnosis of hematological disease

The developments in the fields of genetics and immunology and the application of these informations have significant consequences for the diagnosis of hematological diseases. The present article gives an introduction into the principles of several modern diagnostic techniques, which are applied in the diagnosis of hematological diseases. In addition, it summarizes the application of these techniques in the diagnosis of several acquired and inherited diseases. The most important method of immunophenotyping is FACS (fluorescence activated cell sorting) analysis, which is based on the automated recognition of fluorescently labelled monoclonal antibodies bound to specific antigens on the surface or in the cytoplasm of different cell populations of the immune system. Techniques from molecular biology and from cytogenetics are also relevant for the diagnosis of hematological diseases: they allow the identification of changes of the genetic material on the level of DNA (molecular biology) and chromosomes (cytogenetics). Molecular biological and cytogenetic methods coalesce in the field of molecular cytogenetics, which renders possible the identification of chromosome mutations, which are invisible by the classical cytogenetical approach, and difficult to detect by routine molecular biological analysis. Most hematological malignancies are associated with genomic changes, which can be identified by cytogenetic and/or molecular biological methods. These genetic changes usually correspond with a specific pattern of surface antigens of the tumour cells, which can be identified by FACS. The different mutations in different genes causing a large number of inherited hematological diseases can often be found by molecular analysis, too. For hematological neoplasias, the exact definition of the causative mutations is increasingly important for therapeutic decisions and follow-up analysis of minimal residual disease. For inherited diseases, the identification of mutations is often the basis for a correct genetic counselling of the family.