Dravet综合征SCN1A基因突变的遗传特点及表型研究

目的 研究Dravet综合征(Dravet syndrome,DS)患儿SCN1A基因突变类型和遗传特点,分析家系受累成员临床表型及基因型与表型相关性.方法 收集181例DS患儿及其父母临床资料及外周血DNA,对父母是受累者的,临床表型进行分析,并采用PCR-DNA直接测序和多重连接依赖的探针扩增技术进行SCN1A基因突变筛查.结果 共发现128例患儿有SCN1A突变,突变率占70.7%(128/181).其中包括60例(46.9%)错义突变,55例(43.0%)截断突变,10例(7.8%)剪切位点突变,3例(2.3%)有SCN1A基因片段缺失或重复.证实5例患儿其突变(Y349C、T1658M、T841fsx842、W190R、C373fsx378)遗传自父母一方,遗传突变占3.9%(5/128),其中1例父亲为突变嵌合体(C373fsx378).5例携带突变的父母一方中,1例表型正常,其余4例表型包括热性惊厥1例,热性惊厥附加症2例,无热的全面强直阵挛发作1例.结论 DS患儿SCN1A基因突变率较高,突变类型以错义突变、截断突变为主,少数患儿为SCN1A基因片段缺失或重复.DS患儿SCNIA基因突变以新生突变为主,少数为来源于父母一方的遗传性突变,父母可为SCN1A突变嵌合体,携带突变的父母一方表型正常或较轻.     

1例AP2M1基因突变致智力发育障碍伴癫痫发作的遗传特征与临床表型分析

目的 分析1例智力发育障碍伴癫痫发作患者的临床表型与遗传学特征，明确患者的临床病因。方法 收集患者相关临床资料，采用全外显子组测序对患者及其家系成员进行基因变异筛查，结合既往研究的4例具有相同突变患者的文献报道，分析该基因突变所致的临床表型及遗传特征。结果 患儿，女性，4岁10月龄，运动发育迟缓，智力落后伴有癫痫发作情况。患儿脑电图显示弥漫性棘慢波，慢波显著增多。基因检测结果显示患儿AP2M1基因发生c.508C>T(p.Arg170Trp)新发杂合突变。患者父母、哥哥及舅舅基因型为野生型，舅舅有癫痫病史，其他人未见明显临床症状。对国内外相同突变患者的综合分析显示，该基因突变具有不同程度的智力发育障碍、癫痫发作及共济失调等共有表型。结论 AP2M1c.508C>T(p.Arg170Trp)基因突变为本例患儿的致病原因。本研究表明中国人中存在该基因突变，进一步丰富了智力发育障碍伴癫痫发作疾病的临床表型谱特征，为该病的临床诊治和遗传咨询提供了更多参考数据。     

结节性硬化症患儿2例的临床特征及遗传学分析

目的探讨2例结节性硬化症(TSC)患儿的临床表现及基因变异特点。方法选取2020年6月至2021年7月于郑州大学附属儿童医院就诊的2例TSC患儿为研究对象。收集2例患儿的临床资料, 采用全外显子组测序(WES)筛选患儿的致病基因, 针对可疑变异位点, 进行Sanger测序家系验证。结果患儿1为7月29日龄男性, 患儿2为2岁6月龄男性。2例患儿均表现为癫痫发作和多发性色素脱失斑。基因检测结果显示2例患儿分别携带TSC2基因c.3239₃240insA和c.3330delC新发变异, 既往均未见报道, 根据美国医学遗传学和基因组学学会相关指南, 均评级为致病性变异(PVS1+PS2+PM2_Supporting)。结论本研究明确2例TSC患儿的遗传学病因, 丰富了中国人群TSC的表型和基因变异谱。     

深圳地区苯丙酮尿症患儿苯丙氨酸羟化酶基因突变特征及分布情况研究

目的了解深圳地区苯丙酮尿症(phenylketonuria,PKU)患儿苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)基因突变特征及分布情况,为该地区PKU产前诊断、治疗及干预措施的制定提供科学依据。方法收集2013年2月~2017年9月在深圳市光明新区人民医院产科分娩的新生儿经深圳市新生儿遗传性疾病筛查中心确诊为PKU患儿27例,采用聚合酶链反应(PCR)直接测序法对PKU患者PAH基因突变型进行检测,并对检测结果进行统计分析。结果 27例PKU患儿中检出2个基因突变类型的16例,占59.26%(16/27),其中3例为纯合子突变,明显高于1个基因突变类型的37.04%(10/27)和1例未检出基因突变类型的3.70%(1/27),差异有统计学意义(χ2=3.105~9.683,P0.05);27例PKU患儿54个PAH等位基因中共检出44个基因突变位点,检出率为81.48%(44/54),且此44个突变基因中共检出14种基因突变类型,包括错义突变7个,无义突变3个,剪接突变1个,同义突变1个,缺失突变2个,其中以R243Q,Y356X和R241C突变检出率最高,分别为20.37%,14.81%和12.96%,明显高于其它基因突变类型,差异有统计学意义(χ2=3.921~11.518,P0.05)。结论深圳地区PKU患儿PAH基因突变检出率比较高,且基因突变类型呈现多样化和复杂化,但未检出新的PAH基因突变类型,以R243Q,Y356X和R241C突变类型检出率最高。     

15例甲基丙二酸血症患儿临床特征和基因突变分析

目的分析15例甲基丙二酸血症(MMA)患儿临床特征和基因突变,为家系遗传咨询、产前诊断和新生儿筛查提供依据。方法选择15例先证者MMA患儿,其中男性7例,女性8例;年龄63 h～11岁,中位年龄2岁;cblC型12例(1个月～11岁,中位年龄1岁6个月),mut型3例(年龄63 h、3 d和3岁)。分析其临床资料。应用液相色谱和串联质谱技术对患儿尿液和血液代谢物进行筛查,应用Sanger测序方法结合高通量测序对患儿家系进行相关基因检测和分析。结果 15例MMA患儿临床表现各异,累及全身多系统,常见临床表型主要为癫痫、水电解质紊乱、贫血、粒细胞缺乏和呼吸性/代谢性酸中毒等。在12例cblC型患儿钴胺素代谢相关C基因(MMACHC)中共检测出8种基因突变,包括7种错义突变和1种缺失突变,其中最常见的为c.658-660delAAG、c.609G A和c.80A G,分别占25%(6/24)、20.83%(5/24)和20.83%(5/24)。在3例mut型患儿甲基丙二酰辅酶A变位酶基因(MUT)中共检测出5种基因突变,包括3种错义突变、2种剪接位点突变。结论 MMA亚型cblC型与表型存在一定相关性,mut型临床表现比cblC型更为严重。该研究结果丰富了MMA相关基因突变谱,为遗传咨询、产前诊断和新生儿筛查提供了依据。     

16例PRRT2基因突变家系研究

目的研究富脯氨酸跨膜蛋白2(proline-richtransmenbraneprotein2,PRRT2)基因突变所知疾病谱系分析,来加深对该疾病的认识。方法收集自2017年1月至2018年3月于我院就诊的PRRT2阳性患者及其家系成员的临床资料,就其基因突变特点及其临床表型进行分析;结果共收集16个家系。16个家系中共有40例受累者,包括11个良性家族性婴儿癫痫(BFIE)家系,3个发作性运动诱发性运动障碍(PKD)家系,2个婴儿惊厥伴发作性手足舞蹈徐动征(ICCA)家系。婴儿期惊厥起病年龄为3～12个月,PKD起病年龄为12～16岁。其中外显子2突变占81.3%(13/16),片段缺失占18.8%(3/16)。以c.641_642位点突变最常见,占75%(12/16),该位点dupC占总突变56.3%(9/16),该位点delC占总突变12.5%(2/16)。给予奥卡西平治疗后,均再无抽搐发作及运动障碍。结论 PRRT2为良性家族性婴儿癫痫,发作性运动诱发性运动障碍及婴儿惊厥伴发作性手足舞蹈徐动征致病基因。PPRT2的性状在13个谱系中连续传播,表现出完全的外显率,但在其他3个谱系中,间歇性传播,表现为不完全外显。突变热点为c.641_642。通常奥卡西平治疗有效。     

中国X连锁无丙种球蛋白血症40例基因型表型相关性分析

目的通过中国X连锁无丙种球蛋白血症（XLA）患儿临床表现、免疫功能评价、Bruton＇s酪氨酸激酶（BTK）的表达及BTK基因突变分析,分析基因型和表型间可能存在的关系。方法选取拟诊为XLA患儿,使用抗BTK单克隆抗体通过流式细胞技术分析单核细胞BTK蛋白表达。采用RT-PCR获得患儿cDNA,使用8对不同引物分2步扩增BTKcDNA,PCR产物测序。突变结果通过对DNA外显子相应部位扩增、测序证实。并对确诊XLA患儿的母亲及家族中部分亲属进行BTK蛋白表达和BTK基因分析。结果①40/50例原发性低丙种球蛋白血症患儿经BTK基因突变分析确诊为XLA,以错义突变（16例,40.0%）和无义突变（13例,32.5%）为主。②突变类型为错义突变的患儿平均起病年龄为（1.4±1.1）岁,其他突变类型患儿为（1.4±0.7）岁,差异无统计学意义（P=0.45）。错义突变的发生率随年龄的增长呈上升趋势,无义突变的发生率呈下降趋势。③34/40例（85.0%）B细胞〈0.1%;4例（10.0%）B细胞在1%～2%,其中错义突变2例,无义突变1例,剪接突变1例;2例（5.0%）B细胞为2%,均为错义突变。④血清IgG〈3g·L-1患儿BTK基因突变类型以错义突变和无义突变为主。⑤错义突变患儿BTK蛋白表达水平与其他突变类型无显著差异。⑥6/21例（28.6%）2031C/T多态性患儿伴有严重的关节炎,3/19例（15.8%）无多态性患儿有关节炎表现。⑦28/32例（87.5%）XLA患儿母亲为BTK基因杂合型。结论错义突变可能与确诊年龄较大有关,且某些位点的错义突变可能与较高的外周血B细胞数量和血清IgG水平及正常的BTK蛋白表达水平有关。BTK基因多态性（2031C/T）可能增加关节炎的风险。     

甲基丙二酸血症患儿MUT基因突变分析

目的 检测甲基丙二酸血症(methylmalonic acidemia,MMA)患儿MUT基因突变类型及突变频率,探讨基因型与临床表型之间的关系.方法 依据串联质谱检测血酰基肉碱、气相色谱-质谱检测尿甲基丙二酸以及维生素B_(12)负荷试验等,诊断21例单纯MMA患儿;采用聚合酶链反应和直接测序法对这些患儿进行MUT基因突变检测分析.结果 在21例单纯MMA患儿中14例检测到17种MUT基因突变,其中8种为未报道突变.以c.323G>A(R108H)、c.729_730insTT(D244LfsX39)与c.1630_1631GG>TA(G544X)较为常见,突变频率分别为14.3%、10.7%及14.3%,以错义突变多见(64.7%).14例MUT突变患儿中10例为早发型,1例为迟发型,3例由新生儿出生筛查检出;11例为维生素B_(12)无效型,3例为有效型.结论 揭示了中国MMA患儿中MUT基因的部分突变谱,MUT基因突变患儿发病较早,多为维生素B_(12)无效型.     

SCN8A基因变异致癫痫5例患儿的临床特征及遗传学分析

目的探讨5例SCN8A基因变异所致癫痫患儿的临床及遗传学特点。方法收集2015年8月至2022年8月在临沂市人民医院拟诊为遗传性癫痫患儿的临床资料, 对其进行家系全外显子组测序, 对候选变异进行Sanger测序家系验证。结果共筛选出5例(4男1女)携带SCN8A变异的患儿。患儿1具有良性家族性婴儿癫痫, 携带遗传自父亲(具有相似表型)的c.4840A>G变异, 为已报道致病性变异。患儿2～4为中间型癫痫。患儿2携带c.3967G>A新发变异, 根据美国医学遗传学与基因组学学会(ACMG)相关指南评级为致病性变异(PS1+PS2+PM1+PM2_Supporting+PP3), 患儿3携带c.415A>T变异, 患儿4携带c.4697C>T新发变异, 均评级为可能致病性变异(PS2+PM1+PM2_Supporting+PP3)。患儿5具有早期婴儿癫痫性脑病, 之后转变为类Lennox-Gastaut综合征, 携带c.5615G>A新发变异, 为已报道致病性变异。5例患儿的首次发病年龄为2 ～ 14个月, 均存在局灶性...     

海南省澄迈县人群G6PD缺乏症基因突变分析

目的分析海南省澄迈县人群葡萄糖-6-磷酸脱氢酶缺乏症(G6PD)的发病率及基因突变类型。方法用Zinkham法对1 299例(男650例,女649例)标本进行G6PD缺乏筛查;用多色探针荧光PCR熔解曲线法对初筛的阳性标本进行中国人常见的16种G6PD基因突变类型检测,对未检出突变的标本进行外显子测序。结果澄迈县人群的G6PD缺乏症总发生率为5.54%(72/1 299),其中男性发生率为6.62%(43/650),女性发生率为4.47%(29/649)。72例阳性标本中有61例检测出有突变,共检出6种基因点突变,含24例1 376 GT(33.33%),19例1 388 GA(26.39%),4例95 AG(5.56%),6例1 024 CT(8.33%),4例392 GT(5.56%),3例871 GA(4.17%),1例1 376 GT复合1 388 GA突变(1.39%)。未检出突变的11例(15.28%)标本经外显子测序未发现新突变。结论澄迈县G6PD缺乏症发生率高,以1 376 GT和1 388 GA突变基因型为主。     

结节性硬化症家系的基因诊断及产前诊断

目的 对结节性硬化症(tuberous sclerosis complex,TSC)患者进行基因突变检测,并在基因诊断结果明确的基础上应用于产前诊断.方法 应用聚合酶链反应-变性高效液相色谱(polymerase chain reaction-denaturing high-performance liquid chromatography,PCR-DHPLC)、DNA测序技术,对19个家系的21例TSC患者进行TSC1和TSC2基因的突变检测.结果 在19个家系21例患者中发现17种不同的基因突变,其中13种突变未见报道,包括TSCj基因的c.2672delA、c.2672insA和TSC2基因的c.4918insCGCC、c.1143delG、Intron27+1 G＞A、c.1957-1958delAG、Intron5+1 G＞A、c.910insCT、c.2753C＞G、c.4078dupAGCAAGTCCAGCTCCTC、Intron 11-1 G＞A、Intron 14+1 G＞A、c.684 C＞A.对7个家系进行了产前诊断,其中6个家系的胎儿均未发现其家系先证者所具有的突变,胎儿出生后电话随访至1～4岁无TSC的症状出现.而另一家系的胎儿携带有和母亲一样的突变,经遗传咨询后,家属选择了引产.结论 本研究证实的TSC基因突变中,有76.5%(13/17)的突变均未在其他研究中被发现,说明中国人群TSC基因的突变谱可能与其他人群具有较明显的差异;本研究中TSC基因诊断率为89.5%(17/19),提示TSC的发生可能还有其它未知的遗传病因;在有家族史的病例中,TSC1与TSC2有相似的突变比例,而在散发病例中,TSC2的突变更加常见;13种新突变患者的父母均无类似突变,说明TSC致病基因具有较高的自发突变率.     

Protein truncation test for screening hamartin gene mutations and report of new disease-causing mutations.

Considering the prevalence of truncating mutations in the tuberous sclerosis (TSC) hamartin gene (TSC1), we devised a protein truncation test (PTT) to analyze the full length coding sequence of TSC1. Studying 12 sporadic cases and three familial forms by a combination of PTT and single-strand conformation polymorphism analysis (SSCA), we found 5/15 mutations while PTT alone detected 4/15 truncating mutations, two of which escaped SSCA analysis. SSCA alone picked up one missense mutation and two mutations also detected by PTT. Interestingly, a TSC1 mutation was identified in all three familial forms (3/3) while the rate of mutation detection was lower in sporadic cases (2/12). In conclusion, PTT proves to be a useful technique for the rapid detection of disease-causing mutations in the TSC1 gene.     

Mutational analysis of the TSC1 and TSC2 genes in a diagnostic setting: genotype--phenotype correlations and comparison of diagnostic DNA techniques in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by the development of hamartomas in multiple organs and tissues. TSC is caused by mutations in either the TSC1 or TSC2 gene. We searched for mutations in both genes in a cohort of 490 patients diagnosed with or suspected of having TSC using a combination of denaturing gradient gel electrophoresis, single-strand conformational polymorphism, direct sequencing, fluorescent in situ hybridisation and Southern blotting. We identified pathogenic mutations in 362 patients, a mutation detection rate of 74%. Of these 362 patients, 276 had a definite clinical diagnosis of TSC and in these patients 235 mutations were identified, a mutation detection rate of 85%. The ratio of TSC2:TSC1 mutations was 3.4:1. In our cohort, both TSC1 mutations and mutations in familial TSC2 cases were associated with phenotypes less severe than de novo TSC2 mutations. Interestingly, consistent with other studies, the phenotypes of the patients in which no mutation was identified were, overall, less severe than those of patients with either a known TSC1 or TSC2 mutation.     

Exon scanning of the entire TSC2 gene for germline mutations in 40 unrelated patients with tuberous sclerosis

Tuberous sclerosis complex (TSC) is a dominantly inherited multisystem disorder resulting in the development of hamartomatous growths in many organs. Genetic heterogeneity has been demonstrated linking the familial cases to either TSC1 at 9q34.3, or TSC2 at 16p13.3. About two-thirds of the TSC cases are sporadic and appear to represent new mutations. While both genes are thought to account for all familial cases, with each representing approximately 50% of the mutations, the proportion of sporadic cases with mutations in TSC1 and TSC2 is yet to be determined. We have examined the entire coding sequence of the TSC2 gene in 20 familial and 20 sporadic cases and identified a total of twenty-one mutations representing 50% and 55% of familial and sporadic cases respectively. Our rate of mutation detection is significantly higher than other published reports. Twenty out of 21 mutations are novel and include 6 missense, 6 nonsense, 5 frameshifts, 2 splice alterations, a 34 bp deletion resulting in abnormal splicing, and an 18 bp deletion which maintains the reading frame. The mutations are distributed throughout the coding sequence with no specific hot spots. There is no apparent correlation between mutation type and clinical severity of the disease. Our results document that at least 50% of sporadic cases arise from mutations in the TSC2 gene. The location of the mutations described here, particularly the missense events, should be valuable for further functional analysis of this tumor suppressor protein. Hum Mutat 12:408–416, 1998. © 1998 Wiley-Liss, Inc.     

Molecular genetic and phenotypic analysis reveals differences between TSC1 and TSC2 associated familial and sporadic tuberous sclerosis

Tuberous sclerosis (TSC) is an autosomal dominant disorder characterised by the development of hamartomatous growths in many organs. Sixty to seventy percent of cases are sporadic and appear to represent new mutations. TSC exhibits locus heterogeneity: the TSC2 gene is located at 16p13.3 whilst the TSC1 gene, predicted to encode a novel protein termed hamartin, has recently been cloned from 9q34. With the exception of a contiguous gene deletion syndrome involving TSC2 and PKD1 , TSC1 and TSC2 phenotypes have been considered identical. We have now comprehensively defined the TSC1 mutational spectrum in 171 sequentially ascertained, unrelated TSC patients by single strand conformation polymorphism and heteroduplex analysis of all 21 coding exons, and by assaying a restriction fragment spanning the whole locus. Mutations were identified in 9/24 familial cases, but in only 13/147 sporadic cases. In contrast, a limited screen revealed TSC2 mutations in two of the familial cases and in 45 of the sporadic cases. Thus TSC1 mutations were significantly under-represented among sporadic cases (Fisher's exact p -value = 3.12 x 10(-4)). Both large deletions and missense mutations were common at the TSC2 locus whereas most TSC1 mutations were small truncating lesions. Mental retardation was significantly less frequent among carriers of TSC1 than TSC2 mutations (odds ratio 5.54 for sporadic cases only, 6.78 +/- 1.54 when a single randomly selected patient per multigeneration family was also included). No correlation between mental retardation and the type of mutation was found. We conclude that there is a reduced risk of mental retardation in TSC1 as opposed to TSC2 disease and that consequent ascertainment bias, at least in part, explains the relative paucity of TSC1 mutations in sporadic TSC.      

Analysis of all exons of TSC1 and TSC2 genes for germline mutations in Japanese patients with tuberous sclerosis: report of 10 mutations

Twenty-seven Japanese patients with the tuberous sclerosis complex (TSC), consisting of 23 sporadic and 4 familial cases, were tested for mutations in the TSC1 and TSC2 genes, using single-strand conformational polymorphism analysis and direct sequencing. Four possible pathogenic mutations were found in the TSC1 gene, including three frame shifts and a nonsense mutation in a familial case. All mutations were expected to result in a truncated hamartin gene product. The TSC2 gene analysis identified six possible pathogenic mutations only in the sporadic cases, including two frame shifts, one in-frame deletion, and three missense mutations. Two of the TSC2 mutations were expected to result in a truncated tuberin gene product. These results of the Japanese TSC patients were compatible with the reports from Europe and the United States, i.e., (1) TSC1 mutations are rarer in sporadic cases than in familial cases, (2) substantial numbers of sporadic cases arise from mutations in the TSC2 gene, and (3) mutations of the TSC1 gene may cause premature truncation of hamartin.     

结直肠癌患者BRAF,KRAS,NRAS和PIK3CA基因突变与其病理正的关系

目的:探讨265例结直肠癌患者BRAF,KRAS,NRAS和PIK3 CA基因突变及其病理特征关系.方法:选取2014年12月至2016年12月的265例结直肠癌患者肿瘤组织标本进行回顾性分析,采用PCR扩增-直接测序法检测BRAF基因(1 5外显子600密码子),KRAS基因(12,13,61密码子突变),NRAS(2号与3号外显子的12密码子、13密码子与61密码子常见的12个突变位点)及PIK3 CA(第9,20外显子)基因的突变状态,分析其与结直肠癌临床病理特征的关系.结果:265例患者中存在BRAF基因突变率为6.8％(18/265),KRAS基因突变率为32.1％(85/265),NRAS基因突变率为5.7％(15/265),PIK3 CA基因突变率为11.3％(30/265).NRAS基因和KRAS基因突变与年龄有关(P＜0.05),与性别、原发部位、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关(P＞0.05);BRAF,PIK3 CA基因在原发部位为右半结肠患者中的突变率明显升高(P＜0.05),但与年龄、性别、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关(P＞0.05).结论:NRAS,PIK3 CA基因在中国结直肠癌患者中的突变率较低.KRAS,NRAS基因突变与年龄相关,BRAF,PIK3 CA基因与肿瘤原发部位相关,联合检测这些基因的突变情况可以判断疾病的发生发展.     

276例手术切除肺腺癌亚型与EGFR/ALK基因状态

目的:探讨手术切除肺腺癌各亚型EGFR和ALK基因状态分布.方法:应用ARMS方法检测手术切除肺腺癌石蜡组织中EGFR基因突变和ALK融合基因情况.结果:276例肺腺癌手术样本中,EGFR基因突变率为54.71％(151/276),其中19del为28.99％(80/276),L858R为23.19％(64/276),20-ins为0.72％(2/276),L861Q为0.72％(2/276),G719X为1.09％(3/276),S768I为0.36％(1/276)和T790M为0.72％(2/276),其中包含G719X+S768I,19del+T790M,L858R+T790M各1例,ALK基因融合阳性率为5.80％(12/207),在肺腺癌各亚型中EGFR基因突变附壁状腺癌,腺泡状腺癌,乳头状腺癌,实体状腺癌和浸润性黏液腺癌之间差异有统计学意义(P＜0.001,P=0.009,P=0.023,P＜0.001和P=0.030),与其他类型之间差异均无统计学意义(P＞0.05);在肺腺癌各亚型中ALK融合基因突变各亚型之间差异均无统计学意义(P＞0.05).结论:肺腺癌组织学亚型与EGFR基因突变有关,附壁状腺癌、腺泡状腺癌和乳头状腺癌出现EGFR基因突变比其他亚型更加明显.     

Identification of a nonsense mutation at the 5'' end of the TSC2 gene in a family with a presumptive diagnosis of tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited disease with a high mutation rate. It is clinically a very variable disorder and hamartomas can occur in many different organs. TSC shows genetic heterogeneity; one gene, TSC1, is on chromosome 9q34, and the second gene, TSC2, on chromosome 16p13.3. Clinical criteria for diagnosis have been established, but diagnosis of patients with minimal expression of the disease can be very difficult. In children the phenotype is often incomplete or not fully assessable. Hence mildly affected subjects, at risk for severely affected offspring, may remain undiagnosed. The detection of (small) mutations in the tuberous sclerosis gene located on chromosome 16 (TSC2) has recently become possible and may be helpful in the diagnosis of ambiguous cases. To our knowledge, this is the first report of a point mutation in the TSC2 gene in a familial case of tuberous sclerosis. A nonsense mutation was detected in a family in which the father had only minor signs hinting at tuberous sclerosis. The son had multiple cardiac tumours and white patches, but full clinical investigation was impossible in this child. This case illustrates that mutation analysis can contribute to a diagnosis of tuberous sclerosis in families with an incomplete phenotype.     

非小细胞肺癌中表皮生长因子受体基因突变直接测序分析及其与临床病理特征的相关性

目的回顾性分析非小细胞肺癌(NSCLC)中采用直接测序法检测的表皮生长因子受体(EGFR)基因突变率、突变分布特征及其与临床病理的相关性。方法收集NSCLC共443例,其中包括手术切除样本299例、粗针穿刺活检标本59例、细针穿刺和胸腔积液细胞学样本85例。所有样本均通过石蜡包埋、切片后确定肿瘤细胞含量,显微切割富集肿瘤细胞后采用聚合酶链反应-直接测序法检测EGFR基因酪氨酸激酶编码区第18至21号外显子的突变。结果(1)在443例NSCLC标本中共检出EGFR基因突变193个,发生在189例患者中(42.7％);EGFR基因第18至21号外显子的突变率分别为2.0％( 4/193)、48.7％ (94/193)、6.7％ (13/193)和42.5％ (82/193);(2)EGFR基因总突变率与年龄无显著相关性,但在年龄大于中位年龄（57岁）的患者中第21号外显子的突变率(50.9％,54/106)高于年龄小于或等于中位年龄者(32.2％,28/87;P＜0.01);(3)女性患者中EGFR基因突变率(53.5％,107/200)高于男性患者突变率(33.7％,82/243;P ＜0.01);(4)腺癌中的突变率(46.5％,161/346)高于鳞癌(13.3％,4/30;P＜0.01)和低分化癌者(24.1％,7/29;P＜0.05),而与腺鳞癌(7/13)差异无统计学意义(P＞0.05);(5)在手术切除、粗针穿刺活检以及细针穿刺和胸腔积液细胞学样本中EGFR突变检出率有逐渐下降的趋势,分别为49.5％( 148/299)、35.6％ (21/59)和23.5％ (20/85),其中细针穿刺和胸腔积液的细胞学样本中的检出率较手术标本中的检出率为低(P＜0.01)。结论直接测序法是检测NSCLC中EGFR基因突变的有效方法,特别对未知突变类型的检出具有优势;NSCLC中EGFR基因突变在女性和腺癌中多见,以第19号外显子的缺失突变和第21号外显子的点突变为主;EGFR基因突变分布特征可能与年龄有一定关系;EGFR基因突变检出率与样本类型密切相关,活检组织及细胞学样本是检测EGFR基因突变的有用材料,但可能会漏检部分患者中EGFR基因的突变。