GUCY2D基因复合杂合致Leber氏先天性黑蒙合并妊娠1例

目的 对一例GUCY2D基因复合杂合变异导致的罕见遗传病,Leber氏先天性黑蒙1型合并妊娠患者的突变基因进行分子检测及分析,并为该家系提供适当的遗传学咨询。方法 收集先证者及其配偶临床资料,应用全外显子组测序技术(WES)对两人外周血来源DNA进行分子遗传学检测,并用Sanger DNA测序技术对双方亲属进行验证分析,检测结果由专业的遗传学医师进行解读并为患者提供遗传学咨询。结果 患者本人及其丈夫患有严重视力障碍,患者表现为严重的视力障碍,色盲,夜间视力优于白天视力,但无眼球震颤,无儿童期刺激性“戳眼”,无中心视野缺损,无夜盲主诉,对患者查体未见皮肤及毛发色素沉着有特殊改变,神经查体未见异常,双眼视力无法测得。患者未接受任何相关干预性治疗。其丈夫患有白化病,对患者及其家系进行分子检测发现患者GUCY2D基因存在NM＿000180.3:c.721G>C(p.Ala241Pro)和NM＿000180.3:c.542G>A(p.Trp181^*)两种变异的复合杂合状态,两种不同的变异分别来自患者父亲和母亲,两变异目前均为疑似致病变异,此复合杂合致病目前国内尚...     

一例复合杂合突变导致遗传性凝血因子Ⅺ缺陷症患者的表型与遗传学分析

目的 对1例遗传性凝血因子Ⅺ(FⅪ)缺陷症患者进行凝血指标与基因水平的分析,初步探讨其分子发病机制.方法 用ELISA方法检测FⅪ 抗原(FⅪ :Ag),用一期凝固法检测活化部分凝血活酶时间(APTT)、FⅪ 活性(FⅪ :C)等相关凝血指标,并进行表型诊断.用Sanger测序法分析先证者F11基因所有外显子、侧翼序列...     

IDUA基因复合杂合突变致黏多糖贮积症Ⅰ型1例报告

目的 探讨黏多糖贮积症Ⅰ型的临床表型及基因型。方法 回顾分析l例黏多糖贮积症Ⅰ型患儿的临床资料。结果 患儿,男,9月13天。5个月时出现双眼无神,眼科检查发现双眼角膜混浊。临床表型及外周血α-L-艾杜糖苷酶（IDUA）活性检测符合黏多糖贮积症Ⅰ型（MPSⅠ）。全外显子测序发现：在4p16.3区域存在大片段杂合缺失,缺失段为（980784-985463）×1;在c.911delT和c.76G>A存在1个杂合突变和一个半合子突变,均来源于母亲。结论 本例患儿为IDUA基因复合杂合突变致黏多糖贮积症I型发病,临床罕见。     

罕见 PROC基因复合杂合变异所致蛋白C缺乏症胎儿1例的临床及遗传学分析

目的探讨1例脑积水和脑室出血胎儿的遗传学病因, 为其产前诊断提供依据。方法应用全外显子组测序(WES)技术筛选与胎儿表型相符的基因变异, 对候选变异进行Sanger测序验证。结果胎儿存在PROC基因c.818G>A(p.W273X)和c.833T>C(p.L278P)复合杂合变异, 分别遗传自其母亲和父亲。按照美国医学遗传学与基因组学学会(ACMG)相关指南, 二者均被判定为可能致病变异(PVS1_Strong+PM2_Supporting+PP4;(PM2_Supporting+PM3+PP1+PP3+PP4)。结论本研究胎儿被诊断为由PROC基因c.818G>A(p.W273X)和c.833T>C(p.L278P)复合杂合变异所致的蛋白C缺乏症。上述发现丰富了PROC基因的变异谱, 为其家系的遗传咨询和产前诊断提供了依据。     

基因复合杂合变异导致卵母细胞透明带缺失而不孕

目的探讨1例原发不孕伴卵母细胞透明带缺失患者的遗传学病因。方法应用全外显子组测序技术对患者及其父母ZP1基因进行变异检测、Sanger测序及生物信息学分析。结果检出患者ZP1基因第5外显子c.874C>T(Gln292*)及第7外显子c.1127₁128delCT(ALa376GlyTer386)的复合杂合变异,母亲携带c.874C>T(p.Gln292*)杂合变异,父亲携带c.1127₁128delCT(p.Ala376GlyTer386)的杂合变异。结论患者者ZP1基因复合杂合变异是导致其卵母细胞透明带缺失的可能遗传学病因。     

一例先天性白内障患儿的 GJA8基因新复合杂合变异分析

目的明确1例先天性白内障患儿的遗传学病因, 为该家系的临床诊断及遗传咨询提供依据。方法应用高通量测序技术对先证者进行遗传性眼病相关基因检测, 筛选相关变异, 采用Sanger测序法对先证者及家庭成员进行变异位点的验证。结果基因检测结果显示先证者发生源自父母的GJA8基因c.855del和c.872dup的复合杂合变异, 这两个变异均未见报道。根据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics, ACMG)遗传变异分类标准与指南, 对这两个变异进行分析, GJA8基因c.855del判读为可能致病性(likely pathogenic)变异(PVS1_S+PM2+PP4), c.877dup为致病性(pathogenic)变异(PVS1_S+PM2+PM3+PP4)。结论 GJA8基因c.855del和c.872dup的复合杂合变异可能为这例先天性白内障患儿的致病原因。     

两个 FGB基因c.1115 T>A杂合变异导致的遗传性异常纤维蛋白原血症家系的表型及遗传学分析

目的对2个遗传性异常纤维蛋白原血症家系进行临床表型和基因型分析, 初步探讨其发病机制。方法采集先证者及其家系成员的外周血并进行常规出凝血、血浆纤维蛋白原活性(fibrinogen activity, Fg∶A)和纤维蛋白原抗原(fibrinogen antigen, Fg∶Ag)检测。用PCR方法扩增纤维蛋白原FGA、FGB和FGG基因的所有外显子及其侧翼序列, 扩增产物纯化后直接测序分析, 寻找基因变异位点;用4个生物信息学预测软件对变异进行功能预测;采用PyMol软件对变异蛋白进行结构分析;用Clustal X软件分析变异氨基酸的保守性。结果 2例先证者凝血酶时间(thrombin time, TT)延长且不能被硫酸鱼精蛋白校正, Fg∶A明显降低, 分别为(1.25 g/L和1.17 g/L), 但Fg∶Ag含量正常, 分别为(3.50 g/L和3.81 g/L)。基因分析显示2例先证者均为FGB第7外显子c.1115 T>A(p.Val372Glu)杂合错义变异, 变异均来源于父亲。4个生物信息学软件预测结果均表示此变异为有害变异。根据美国医学遗传学与基因组学学会遗传变异...     

KRAS G12C突变的非小细胞肺癌患者的基因突变谱及临床病理学特征的单中心回顾性研究

目的为了精准地筛选出携带KRAS G12C突变的非小细胞肺癌(NSCLC)患者, 并评估其临床病理学特征、预后影响因素及目前的治疗现状。方法回顾性筛查上海市胸科医院病理科2018年1月至2021年9月的19 410例NSCLC标本, 筛选经二代测序检测为KRAS基因突变的病例, 收集并分析这些病例的临床病理学特征和基因突变数据。结果共1 633例(8.4%)NSCLC病例携带KRAS基因突变, 其中G12C(468例, 28.7%)是最主要的突变亚型;该突变更常见于男性(414/468, 88.5%)、有吸烟史(308/468, 65.8%)、病理类型为肺浸润性腺癌(231/468, 49.4%)的患者。KRAS G12C突变型NSCLC最常见的共突变基因包括:TP53(52.4%, 245/468)、STK11(18.6%, 87/468)和ATM(13.2%, 62/468)。KRAS G12C突变型NSCLC相较于非G12C突变患者, PD-L1表达(≥1%)的比例显著升高[64.3%(90/140)比56.1%(193/344), P=0.014], 且接受免疫检查点抑制剂(I...     

A Novel KCNJ13 Nonsense Mutation and Loss of Kir7.1 Channel Function Causes Leber Congenital Amaurosis (LCA16)

Mutations in the KCNJ13 gene that encodes the inwardly rectifying potassium channel Kir7.1 cause snowflake vitreoretinal degeneration (SVD) and leber congenital amaurosis (LCA). Kir7.1 controls the microenvironment between the photoreceptors and the retinal pigment epithelium (RPE) and also contributes to the function of other organs such as uterus and brain. Heterologous expressions of the mutant channel have suggested a dominant‐negative loss of Kir7.1 function in SVD, but parallel studies in LCA16 have been lacking. Herein, we report the identification of a novel nonsense mutation in the second exon of the KCNJ13 gene that leads to a premature stop codon in association with LCA16. We have determined that the mutation results in a severe truncation of the Kir7.1 C‐terminus, alters protein localization, and disrupts potassium currents. Coexpression of the mutant and wild‐type channel has no negative influence on the wild‐type channel function, consistent with the normal clinical phenotype of carrier individuals. By suppressing Kir7.1 function in mice, we were able to reproduce the severe LCA electroretinogram phenotype. Thus, we have extended the observation that Kir7.1 mutations are associated with vision disorders to include novel insights into the molecular mechanism of disease pathobiology in LCA16.     

Two Mutations of the C7 Gene, c.1424G > A and c.281-1G > T, in Two Korean Families

Complement C7 deficiency is associated with increased susceptibility to meningococcal infection. The genetic alterations of C7 deficiency are known to be sporadic and heterogeneous worldwide. We investigated molecular basis of C7 deficiency in two unrelated Korean families, in which the index cases suffered from meningococcal meningitis. Exon-specific PCR and direct sequencing of the C7 gene revealed two different mutations: c.1424G > A and c.281-1G > T. In family 1, index case and her brother revealed a homozygous mis-sense mutation (c.1424G > A), a novel mutation, which results in the change of cysteine to tyrosine (C475Y) in exon 10. Index case in family 2 was found to be a homozygote carrying point mutation at the 3′ splice acceptor site of intron 3 (c.281-1G > T), which was previously reported in a Korean C7-deficient subject.     

Heterologous expression and characterization of a rare Gaucher disease mutation (c.481C > T) from a Canadian aboriginal population using archival tissue samples.

Gaucher disease is an inherited sphingolipidosis resulting from deleterious mutations in the glucocerebrosidase gene. Through direct sequence analysis of genomic DNA from whole blood, fibroblast cultures, and formalin-fixed archival tissue samples, we have identified a rare homozygous C > T transition at cDNA nucleotide 481 of the glucocerebrosidase gene that results in a proline to serine amino acid substitution (p.P122S) in an aboriginal family of Cree descent in northern Alberta, Canada. A 13-month-old boy (JB) presented with severe visceral Gaucher disease and was treated with enzyme replacement. Currently, at 11 years he is developmentally delayed, with oculomotor apraxia. A cousin (MS) had previously died at age 7 from complications of severe Gaucher disease, before enzyme replacement therapy was available. She was also developmentally delayed. Heterologous expression of this allele using a baculovirus expression system revealed 19.2% of normal enzyme activity on the artificial substrate 4-methylumbelliferyl beta-d-glucopyranoside (4MUGP). Genotype/phenotype correlation is complicated by incomplete clinical details, enzyme replacement therapy, and the difficulty in excluding other genetic and environmental causes of developmental delay. However the development of oculomotor apraxia in JB suggests a Type 3 Gaucher phenotype. The only previous report of this mutation was also from a member of the Cree Nation, who has had a rather similar clinical course. A protocol is described for the isolation of genomic DNA from formalin-fixed bone marrow aspirate archival specimens obtained from the deceased for subsequent PCR-based sequence analysis and mutation detection. This technique will be applicable to the screening of this and other populations for the frequency of known Gaucher mutations where traditional DNA sources are unavailable.     

A promoter polymorphism (-839 C > T) at the dopamine transporter gene is associated with attention deficit/hyperactivity disorder in Brazilian children.

The dopamine transporter (DAT) plays a key role in the regulation of dopaminergic neurotransmission and is also the major site of action for methylphenidate which is one of the main drugs used to treat attention deficit hyperactivity disorder (ADHD). Most association studies with ADHD have concentrated on the 3'-untranslated region of the gene (3'-UTR) mainly in a variable number of tandem repeat (VNTR) polymorphism, but these investigations have reported discordant results. In this study, we tested this VNTR polymorphism and an additional promoter polymorphism -839 C>T (Rs: 2652511) using family-based association analyses in a sample of 243 Brazilian ADHD children and adolescents and their parents. No significant linkage disequilibrium between the two polymorphisms was detected in this sample (D' = 0.56; P = 0.22). No evidence of association with the VNTR polymorphism was found. A significant association (P = 0.03) for biased transmission of the C allele at the -839 C>T polymorphism to ADHD children in the total sample was observed, which was strengthened when the analyses were restricted to the ADHD combined type (P = 0.004). Our results suggest a role for the promoter region of DAT1 gene in ADHD susceptibility in this Brazilian sample.     

A prevalent pathogenic GAMT mutation (c.59G>C) in Portugal

Guanidinoacetate methyltransferase (GAMT) deficiency (MIM 601240), an autosomal recessive disorder of creatine biosynthesis, presents with mental retardation, extrapyramidal symptoms, autistic-like behavior and epilepsy. Other hallmarks are cerebral creatine deficiency, increased levels of guanidinoacetate in body fluids and mutations in the GAMT gene. Creatine supplementation partially restores cerebral creatine content. Worldwide, 29 patients have been identified and 15 different mutations have been reported in the GAMT gene. Ten out of these 29 patients are of Portuguese origin. Likely, a founder effect and a high carrier rate in Portugal exist, since in 17 out of the 20 Portuguese alleles the c.59G>C; p.Trp20Ser mutation was found. We investigated the carrier rate of the c.59G>C; p.Trp20Ser mutation in different regions of Portugal and confirmed the pathogenic nature of this missense mutation by transient transfections. Anonymous bloodspots (1002) were screened for the presence of the c.59G>C; p.Trp20Ser mutation by SNaPshot (Single Nucleotide Polymorphism Multiplex Kit). Eight carriers of c.59G>C; p.Trp20Ser were detected of which four are derived from the Archipelagos. This suggests that the carrier rate of the c.59G>C; p.Trp20Ser mutation is relatively high in these islands, as well as in other parts of Portugal. It also implies that newborn screening in these regions is warranted for this treatable disorder.     

Bacteriencolonien mit Pseudomelanose in der Leber. (Acute Atrophie)

Ohne ZusammenfassungHierzu Taf. XVI. Fig. 4.