两个MODY2中国家系葡萄糖激酶基因杂合突变的研究

目的 寻找两个典型的MODY2家系的责任基因. 方法 抽提两个MODY2家系成员基因组DNA,PCR扩增、直接测序候选基因葡萄糖激酶(GCK)基因5′端、3′端非翻译区及1～10号外显子,确认突变. 结果 家系1中4人携带GCK基因杂合突变c.661G>A(E221K),先证者为MODY2,另2名突变携带者表现为糖调节受损(IGR),1名突变携带者血糖正常.家系2中2人携带GCK基因杂合突变c.771G>A(W257ter),先证者为MODY2,另1名突变携带者表现为IGR.在这些患者中,饮食控制和增强运动能收到良好效果. 结论 GCK基因突变c.661G>A(E221K)和c.771G>A(W257ter)可能是两个MODY2家系的主要致病基因,其中c.771G>A(W257ter)是一个新发现的突变位点.     

一个葡萄糖激酶基因Gly162Asp错义突变致青少年发病的成年型糖尿病2型家系报告

目的对一个高度怀疑青少年发病的成年型糖尿病2型(MODY2),即葡萄糖激酶(GCK)基因突变所致MODY家系寻找基因突变位点,并探讨其临床特点。方法对1例意外发现血糖升高、无酮症倾向、有糖尿病家族史的10岁女孩采用芯片捕获高通量测序方法进行致病基因检测,发现其携带GCK基因突变,对其家系进行调查,收集家系成员相关临床资料并取得家系成员的外周血基因组DNA,使用Sanger测序技术对家系成员进行筛查。结果该家系的5名成员检测到GCK基因(NM_000162)第5号外显子c.485GA(p.Gly162Asp)杂合错义突变,其中有4例为糖尿病患者,1例为IGR,该突变与糖尿病和IGR共分离,在白种人群中已有报道,在中国人群中为首次发现。结论 GCK基因突变c.485GA是该MODY2家系的主要致病基因。     

青少年的成人起病型糖尿病2型和3型混合家系一例临床分析并文献复习

目的探究葡萄糖激酶基因(GCK)及肝细胞核因子1α基因(HNF-1α)同时突变致青少年的成人起病型糖尿病(MODY)的临床和遗传学特点。方法对北京协和医院2017年9月诊断的一例MODY患者及其家系的临床特征、实验室资料进行分析;对家系成员进行MODY相关致病基因检测。结果该家系的5名成员检测到GCK基因(NM_000162)c.686C>T(p.Thr229Met)杂合突变。其中3名成员同时检测到HNF-1α基因(NM_001306179)c.1531C>G(p.Gln511Glu)杂合突变。结论MODY混合家系GCK及HNF-1α基因突变导致同一家系出现不同的MODY类型。诊断时需考虑混合家系的可能性,以准确诊断。     

一个新的肝细胞核因子1α仪基因突变致青少年的成人起病型糖尿病3型家系报道

目的探讨一个青少年的成人起病型糖尿病（MODY）家系的致病基因。方法对一例发病9年的32岁女性糖尿病患者家系成员进行调查,该家系中有两代糖尿病患者,采用目标区域捕获高深度测序技术在先证者中找到突变基因,使用Sanger测序技术验证突变位点并筛查其他家系成员。结果基因检测发现家系中3个个体携带肝细胞核因子1仅（HNF·1α）基因V380Cfs。39移码突变,该突变在家系中表现为与糖尿病共分离。结论该家系为一个新的HNF-1α仅基因突变所致MODY3家系。     

中国人MODY/NIDDM家系葡萄糖激酶和肝细胞核因子1α基因缺陷的分子筛查

目的 探索包含青少年起病的成人型糖尿病(maturity-onset diabetes of the young,MODY)患者的2型糖尿病家族中可能存在的MODY基因的致病突变。方法 选择MODY基因中突变率最高的葡萄糖激酶(GCK，MODY2)和肝细胞核因子1α(HNF—1α，MODY3)基因的微卫星多态遗传标志在2个包含临床MODY患者的中国人2型糖尿病家系中进行连锁分析，对HNF—1α基因进行全基因外显子的突变筛查--DNA序列直接测定以明确具体的核苷酸突变和所编码的氨基酸的改变。结果 HNF—1α基因标志物在家系50001中MODY3的最大LOD值达到2．38(θ＝0．00)，家系50002中，MODY3最大LOD值达到3．59(θ＝0．00)；两家系均末发现与MODY2连锁的依据。DNA直接测序发现在家系50001中所有家族成员外显子7中存在一个杂合多态SeR487 Asn(AGC／AAC)，该多态在正常人中也可见到；家系50002中NIDDM／MODY个体MODY3基因外显子5编码区存在一个杂合错义突变Tyr322 Asn(TAT→AAT)。结论 GCK基因内或附近的基因变异不是本家系糖尿病的主要致病原因；家系50001中，HNF—1α基因的启动子和所有外显子内没有发现明确的致病突变，但不能否定内含子或其他调节区域的变异可能的致病倾向；由于本家系遗传标志D12S86与糖尿病的连锁LoD最大值达到2．38(9＝0．00)，所以也不能排除HNF—1α基因附近其他未知疾病基因的致病可能。家系50002中HNF—1α基因外显子5中发现的杂合错义突变Tyr(TAT／AAT)Asn有可能是一个疾病关联突变，具体致病的机理有待蛋白质功能研究证实。     

青少年发病的成人糖尿病7型新突变的可能位点

目的通过对一个高度怀疑为青少年发病的成人糖尿病7型(MODY7)家系进行信息收集及基因检测,寻找其基因突变位点,并探讨其临床特点。方法对1例病程20年、长期胰岛素治疗但血糖控制不佳、无酮症倾向、有3代糖尿病家族史的28岁女性患者进行基因检测,发现其携带KLF11基因变异,遂对其家系进行调查,收集家庭成员相关临床资料,并进行致病基因检测。基因检测方法为:首先对先证者采用芯片捕获高通量测序方法寻找致病基因,然后使用Sanger测序技术验证基因突变位点,并对其他家系成员使用Sanger测序技术筛查有无相同基因突变位点。结果该家系共检出2例成员存在KLF11基因杂合突变c.920C>T(编码区第920号核苷酸由胞嘧啶变异为胸腺嘧啶),导致氨基酸改变p.P307L(第307号氨基酸由脯氨酸变异为亮氨酸),为错义突变。这与其临床被诊断为糖尿病相符合。结论本研究的家系为KLF11基因c.920C>T(p.P307L)错义突变导致糖尿病家系,该突变位点可能是MODY7新突变位点。     

四例中国青少年的成人起病型糖尿病2型家系的临床与分子遗传学研究

目的探讨中国青少年的成人起病型糖尿病2型（MODY2）患者的临床特点和分子遗传学特征。方法对2013年2月至8月北京协和医院诊断的4例MODY2家系患者的临床特点及实验室检查资料进行系统性分析并抽提相关家系成员的基因组DNA,聚合酶链式反应（PCR）扩增后进行葡萄糖激酶（GCK）基因直接测序。结果在4例家系中共诊断10例GCK基因突变引起的糖尿病和糖调节受损患者。在8例有临床资料的患者中,高血糖的诊断年龄为5．3～44．0岁,查体是主要发现形式,所有患者血甘油三酯水平均正常或低于正常下限。4个家系的GCK基因检测发现2个新突变c．749G〉A（R250H）和C．781G〉C（G261R）和2个已报突变e．127C〉T（R43C）和c．571C〉T（R191W）。结论中国MODY2患者临床表现多样,GCK基因C．749G〉A突变可能是MODY2的致病原因。     

糖尿病患者的羧基酯脂肪酶基因变异2例结果解读：慎重诊断青少年起病的成人型糖尿病8型

该文报道了2例需要与单基因糖尿病进行鉴别的糖尿病患者。患者起病年龄较早, 有明确三代遗传家族史, 起病初期不使用胰岛素控制血糖, 胰岛功能提示基础和刺激后C肽水平尚可, 胰岛素自身抗体阴性。高通量测序发现位于羧基酯脂肪酶(CEL)基因的造成蛋白质截短型的移码突变, 按照美国医学遗传学与基因组学学会指南属于疑似致病性突变, 拟诊断青少年起病的成人型糖尿病8型(MODY8)。笔者对CEL基因的特点和MODY8的临床特征进行了详细分析, 发现目前证据表明只有位于CEL基因可变数量串联重复序列近端的碱基缺失型突变可以导致MODY, 而报道的2例患者为可变数量串联重复序列远端的碱基缺失型和近端的碱基插入型突变, 不是明确导致MODY8糖尿病的基因突变类型, 更为重要的是, 2例患者的临床表现也不符合MODY8糖尿病的临床特点, 从而最终排除了MODY8的诊断。该文提示临床医师既需要在糖尿病人群中对MODY等单基因糖尿病进行鉴别, 又不能盲目依靠基因检测结果来进行诊断, 要通过对基因型和临床表现的仔细分析进行糖尿病的分型甄别。     

胰岛素基因R46Q突变导致青少年的成人起病型糖尿病一个家系分析

本文报道1个经基因检测确诊为青少年起病的成人型糖尿病（MODY）10型家系。提取先证者外周血DNA,进行特殊类型糖尿病检测包的二代测序。将基因检测结果与遗传学数据库比对,从而发现可疑致病突变,并对先证者亲属相应位点进行Sanger测序验证,结果发现先证者及其两名家系成员于胰岛素基因第2外显子区域发生错义突变c.137G...     

葡萄糖激酶基因突变导致的单基因糖尿病诊治专家共识

葡萄糖激酶基因( GCK)失活突变所致的葡萄糖激酶功能障碍导致的糖尿病是单基因糖尿病(MDM)的常见类型,即 GCK-MDM,以往常称为青少年起病的成人型糖尿病(MODY)2型,简称MODY2或 GCK-MODY。 GCK-MDM的血糖谱、血脂谱、糖尿病相关慢性并发症风险与其他类...     

Ochronosis: a report of a case and a review of literature

A patient with alkaptonuria and ochronotic pigment deposited in articular cartilage and sclerae clinically manifested a serious osteoarthritis of the peripheral and axial joints and synchondrosis, typically involved in long lasting cases of this hereditary defect of homogentisic acid oxidase. This is the first patient with this disorder reported, where a non-cemented total knee prosthesis (PCAR) was applied on both knees. This was possible due to the good quality of the bone stock, which did not seem to be impaired by ochronosis. Our patient had no cardiac symptoms or murmurs, but had a slight calcification in the annulus of aorta observed with echocardiography, a useful new method for screening this disease manifestation. A third new aspect reported is the immunopathology of the synovial tissue. Small pieces of torn-off cartilage were seen embedded in the synovial stroma. This was associated with a slight hyperplasia of the C3bi-receptor positive and proline hydroxylase positive type A and B synovial lining cells. Perivenular infiltrates contained CD2 positive T lymphocytes, mostly belonging to the CD4 subset, and some C3bi-receptor positive monocytes. Activated CD25 positive and immunoglobulin light chain positive T and B lymphocytes were absent or few. Because modern medicine has much to offer to those suffering from this ancient inborn error of metabolism in the form of new specific diagnostic methods and new surgical modes of treatment, such as endoprosthesis surgery and cardiac valve replacement, we also present a literature overview of this interesting condition.     

Report of a case of a giant phytobezoar in a patient with a duodenal bulb ulcer.

A case of a large phytobezoar (750 g weight and with the length of 29 cm) due to Khormalou (Persimmon) is being reported in a young patient with chief complaint of abdominal pains and concomitant duodenal ulcer. Review of the literature in this subject shows that bezoars of this size and weight are relatively rare in healthy individuals.     

Charge of a quasiparticle in a superconductor

Nonlinear charge transport in superconductor–insulator–superconductor (SIS) Josephson junctions has a unique signature in the shuttled charge quantum between the two superconductors. In the zero-bias limit Cooper pairs, each with twice the electron charge, carry the Josephson current. An applied bias V_SD leads to multiple Andreev reflections (MAR), which in the limit of weak tunneling probability should lead to integer multiples of the electron charge ne traversing the junction, with n integer larger than 2Δ/eV_SD and Δ the superconducting order parameter. Exceptionally, just above the gap eV_SD ≥ 2Δ, with Andreev reflections suppressed, one would expect the current to be carried by partitioned quasiparticles, each with energy-dependent charge, being a superposition of an electron and a hole. Using shot-noise measurements in an SIS junction induced in an InAs nanowire (with noise proportional to the partitioned charge), we first observed quantization of the partitioned charge q = e*/e = n, with n = 1–4, thus reaffirming the validity of our charge interpretation. Concentrating next on the bias region eV_SD ～ 2Δ, we found a reproducible and clear dip in the extracted charge to q? ～ 0.6, which, after excluding other possibilities, we attribute to the partitioned quasiparticle charge. Such dip is supported by numerical simulations of our SIS structure.Excitations in superconductors (Bogoliubov quasiparticles) can be described according to the Bardeen–Cooper–Schrieffer (BCS) theory (1) as an energy-dependent superposition of an electron with amplitude u(ε), and a hole with amplitude v(ε), where the energy ε is measured relative to the Fermi energy (2). Evidently, the expectation value of the charge operator (applied to the quasiparticle wave function), which we address as the quasiparticle charge e* = q(ε)e, is smaller than the charge of an electron, q(ε) = |u(ε)|² ? |ν(ε)|² (3). Solving the Bogoliubov–de Gennes equations, one finds that |u(ε)|2=1/2[1+(ε2−Δ2/ε)] and |v(ε)|2=1/2[1−(ε2−Δ2/ε)], with the expected charge evolving with energy according to q(ε)=ε2−Δ2/ε––vanishing altogether at the superconductor gap edges (3). Note, however, that the quasiparticle wave function is not an eigenfunction of the charge operator (3, 4). Properties of quasiparticles, such as the excitation spectra (5), lifetime (6–10), trapping (11), and capturing by Andreev bound states (12, 13), had already been studied extensively; however, studies of their charge are lagging. In the following we present sensitive shot-noise measurements in a Josephson junction, resulting in a clear observation of the quasiparticle charge being smaller than e, q(eV_SD∼2Δ) < 1, and evolving with energy, as expected from the BCS theory.To observe the BCS quasiparticles in transport we study a superconductor–insulator–superconductor (SIS) Josephson junction in the nonlinear regime. The overlap between the wave functions of the quasiparticles in the source and in the drain is expected to result in a tunneling current of their effective charge. This is in contrast with systems which are incoherent (14, 15) or with an isolated superconducting island, where charge conservation leads to traversal of multiples of e – Coulomb charge (16). As current transport in the nonlinear regime results from “multiple Andreev reflections” (MAR), it is prudent to make our measurements credible by first measuring the charge in this familiar regime.In short, the MAR process, described schematically in Fig. 1, carries a signature of the shuttled charge between the two superconductors (SCs), being a consequence of n traversals through the junction (as electron-like and hole-like quasiparticles), with n an integer larger than 2Δ/eV_SD. A low transmission probability t (via tunneling through a barrier) in the bias range 2Δ/n < eV_SD < 2Δ/(n ? 1) assures dominance of the lowest order MAR process (higher orders are suppressed as tⁿ), with the charge evolving in nearly integer multiples of the electron charge. Although there is already a substantial body of theoretical (3, 17–23) and experimental (24–29) studies of the MAR process, charge determination without adjustable parameters is still missing. An important work by Cron et al. (27) indeed showed a staircase-like behavior of the charge using “metallic break junctions;” however, limited sensitivity and the presence of numerous conductance channels some of which with relatively high transmission probabilities did not allow exact charge quantization. Our shot-noise measurements, performed on a quasi-1D Josephson junction (single-mode nanowire) allowed clear observation of charge quantization without adjustable parameters. To count a few advantages: (i) the transmission of the SIS junction could be accurately controlled using a back-gate; (ii) this, along with our high sensitivity in noise measurements, enabled us to pinch the junction strongly (thus suppressing higher MAR orders); and (iii) with the Fermi level located near the 1D channel van Hove singularity, a rather monoenergetic distribution could be injected (SI Appendix, section S7).Open in a separate windowFig. 1.MAR. Illustrations of the leading processes contributing to the current as function of bias. In general, for 2Δ/(n ? 1) > eV_SD > 2Δ/n the leading charge contribution to the current is ne. An electron-like quasiparticle is denoted by a full circle, whereas a hole-like quasiparticle is denoted by an empty circle. (A) When the bias is larger than the energy gap, eV_SD > 2Δ, the leading process is a single-path tunneling of single quasiparticles from the full states (Left) to the empty states (Right). This current is proportional to the transmission coefficient t. Higher-order MAR process (dashed box), being responsible for tunneling of Cooper pairs, is suppressed as t². (B) For 2Δ > eV_SD > Δ, the main charge contributing to the current is 2e with probability t². (C) For Δ > eV_SD > 2Δ/3, the main charge contributing to the current is 3e with probability t³.     

Dissection of a viral autoprotease elucidates a function of a cellular chaperone in proteolysis

Replication of positive-strand RNA viruses involves translation of polyproteins which are proteolytically processed into functional peptides. These maturation steps often involve virus-encoded autoproteases specialized in generating their own N or C termini. Nonstructural protein 2 (NS2) of the pestivirus bovine viral diarrhea virus represents such an enzyme. Bovine viral diarrhea virus NS2 creates in cis its own C terminus and thereby releases an essential viral replication factor. As a unique feature, this enzyme requires for proteolytic activity stoichiometric amounts of a cellular chaperone termed Jiv (J-domain protein interacting with viral protein) or its fragment Jiv90. To obtain insight into the structural organization of the NS2 autoprotease, the basis for its restriction to cis cleavage, as well as its activation by Jiv, we dissected NS2 into functional domains. Interestingly, an N-terminal NS2 fragment covering the active center of the protease, cleaved in trans an artificial substrate composed of a C-terminal NS2 fragment and two downstream amino acids. In the authentic NS2, the 4 C-terminal amino acids interfered with binding and cleavage of substrates offered in trans. These findings strongly suggest an intramolecular product inhibition for the NS2 autoprotease. Remarkably, the chaperone fragment Jiv90 independently interacted with protease and substrate domain and turned out to be essential for the formation of a protease/substrate complex that is required for cleavage. Thus, the function of the cell-derived protease cofactor Jiv in proteolysis is regulation of protease/substrate interaction, which ultimately results in positioning of active site and substrate peptide into a cleavage-competent conformation.     

Hemoptysis in a patient with a previous surgical correction of a tetralogy of Fallot

Aorto-bronchial fistula is a rare but associated with a height rare of mortality. Although most reported cases are secondary to infectious aneurysms, cases arising after surgery to correct congenital cardiovascular abnormalities have recently been described. We report the case of a 41-year-old patient with recurrent hemoptysis and a history of Fallot's tetralogy corrected in childhood. Given such a case of hemoptysis in a patient with a history of cardiovascular surgery, the correct diagnostic approach includes fiberoptic bronchoscopy, helicoidal CAT and/or NMR, and aortography. Diagnostic confirmation should be followed soon by corrective surgery.