2例多发性内分泌腺瘤病2A型家系临床分析及RET基因突变研究

  目的  对两例多发性内分泌腺瘤病2A型(MEN-2A)患者的家系进行临床筛查和RET基因突变研究,寻找两个家系中新诊患者及可能存在的RET基因突变,并探寻MEN-2A的分子遗传学发病机制。  方法  对患者进行RET基因外显子测序,对两个家系的未患病成员进行MEN-2A临床筛查,并留取外周血基因组DNA进行突变位点验证。  结果  两个家系均发现RET原癌基因11号外显子第634位密码子的Cys634Arg突变。两个家系共检出4例新诊MEN-2A患者,均携带该突变。此外,家系2中检出1例携带该突变,但尚未发病的患者。  结论  RET原癌基因第11号外显子Cys643Arg突变是两个家系患病的遗传学机制。两个家系均筛查出新诊患者。临床上应对疑诊为MEN-2A患者的家系成员进行筛查。     

RET基因Cys 634 Trp突变致多发性内分泌腺瘤2A型

目的 明确一个多发性内分泌腺瘤2A型（MEN2A）家系致病基因PET的基因型。方法 应用PCR技术对RET基因的第10、11、13、14、15和16外显子进行扩增,将扩增产物纯化后双向测序。结果 先证者及其弟弟RET基因第10、13、14、15和16外显子均无异常,第11外显子的第14996位核苷酸存在C-G替代,其反义链测序为14996 G-C替代,这种替代（TGC-TGG）使编码的氨基酸由半胱氨酸突变为色氨酸（Cys 634 Trp,C 634 W）。正常对照RET基因的第10、11、13、14、15和16外显子区域均未见异常。结论 该MEN2A家系的遗传基础是RET基因Cys 634 Trp突变。     

DelD631:多发性内分泌腺瘤病2A型RET原癌基因的一个新突变

目的 检测一个多发性内分泌腺瘤病2A型（MEN2A）家系中RET原癌基因突变情况,以探寻该家系发病的分子机制。方法一个MEN2A家系,包括先证者两代人共22位成员的大家系。提取该家系22位成员外周血基因组DNA,扩增先证者RET原癌基因的外显子10、11,进而对纯化后的PCR产物直接测序,并进一步进行克隆测序,判定变异的位点及编码氨基酸序列的变化,测得突变所在的外显子后,将其余几例患者及其亲属相应外显子的扩增产物进行测序。结果 4例MEN2A患者均存在13631密码子（GAC）的杂合缺失,碱基序列由TGC^∧GACGAGCTG变为TGCGAGCTG,导致代表天冬氨酸的13631的缺失,即delD631;4例患者中Ⅱ6的一级亲属（Ⅲ10）为该基因突变携带者。克隆测序发现的突变点与Cariff医学遗传学院人类基因突变数据库收录的MEN2A相关的RET原癌基因突变比较,确定为新突变点。结论 本研究MEN2A家系存在外显子11的13631杂合缺失突变,是国内外报道的首个RET原癌基因13631缺失突变。临床表现特点：相对于半胱氨酸位点突变,其发病年龄迟,肾上腺嗜铬细胞瘤可早于甲状腺髓样癌发生。     

一个多发性内分泌腺瘤病2型家系的RET 基因检测

目的：对一个多发性内分泌腺瘤病2型（ multiple endocrine neoplasia 2,MEN2）家系进行RET基因检测,明确诊断和分型,指导治疗、预防及改善预后。方法采用聚合酶链反应和直接基因测序的方法,对一个临床诊断MEN2的家系（共3名家系成员）和3例正常对照的RET原癌基因21个外显子进行测序。结果该家系中的2例患者和1例无症状一级亲属均为RET原癌基因外显子11第634号密码子位点的杂合错义突变TGC→CGC,半胱氨酸→精氨酸（ C634R）。结论通过RET基因检测明确该家系为多发性内分泌腺瘤病2A型,对家系中患者的治疗和随访起到了指导作用,并筛查出家系中无症状的基因突变携带者。     

多发性内分泌腺瘤病2A家系的RET原癌基因突变研究

目的检测一个多发性内分泌腺瘤病2A(MEN 2A)型家系的RET原癌基因突变情况.方法提取16名家系成员外周血基因组DNA,对RET原癌基因第11外显子进行聚合酶链反应(PCR),PCR产物进行直接基因测序.结果家系中1例病理确诊嗜铬细胞瘤的患者存在RET原癌基因第11外显子634密码子错义突变;另外筛查出2名家系成员为该突变基因携带者,其中1例经B超发现甲状腺结节性病灶伴血清降钙素升高.结论 MEN 2A的诊断达到了基因水平,对家系基因筛查可以早期诊断该疾病.     

多发性内分泌腺瘤病2A家系的RET原癌基因突变研究

目的 检测一个多发性内分泌腺瘤病2A(MEN 2A)型家系的RET原癌基因突变情况。方法 提取16名家系成员外周血基因组DNA，对RET原癌基因第ll外显子进行聚合酶链反应(PCR)，PCR产物进行直接基因测序。结果 家系中l例病理确诊嗜铬细胞瘤的患者存在RET原癌基因第ll外显子634密码子错义突变；另外筛查出2名家系成员为该突变基因携带者，其中l例经B超发现甲状腺结节性病灶伴血清降钙素升高。结论 MEN2A的诊断达到了基因水平，对家系基因筛查可以早期诊断该疾病。     

多发性内分泌肿瘤1型6例及其家系研究

目的:分析6例多发性内分泌肿瘤1型(MEN1)患者及其家系成员的临床特点,研究MEN1基因突变特征?方法:收集患者及家系成员的临床资料,提取6例患者及其各自家系成员(共13例)外周血DNA,对MEN1基因编码区9个外显子进行PCR扩增,产物直接测序?结果:家系1中2例患者和2例家系成员MEN1基因第10外显子存在杂合突变c.1378C>T,家系2中1例患者MEN1基因第2外显子存在杂合突变c.80C>G,家系3中先证者及其母亲MEN1基因第9外显子存在杂合突变c.1225T>C,其余人员均未发现突变?其中MEN1基因突变c.80C>G和c.1225T>C为新发现的突变类型,c.1378C>T为已知突变类型?结论:MEN1基因突变分析有助于MEN 1患者早期诊断及其亲属的筛查?本研究发现2种新的MEN1突变类型能增加研究者对于MEN1遗传学特征的认识?     

一个RET原癌基因Met918Thr突变的多发性内分泌腺瘤病Ⅱb家系报道

目的 检测一个多发性内分泌腺瘤病(MEN)Ⅱb家系的RET原癌基因突变。方法 提取患者及其父母的外周血基因组DNA，对RET原癌基因第16外显子进行聚合酶链反应(PCR)，将PCR扩增产物进行直接基因测序和限制性内切酶分析。结果 检测到患者RET原癌基因第16外显子918密码子存在ATG(Met)／ACG(Thr)点突变，而在患者父母中未检测到该突变。结论 通过对MENⅡb患者及其父母的基因筛查发现，该患者点突变是杂合子错义突变。该疾病的诊断达到了基因水平。     

新的 MEN1基因剪切突变导致多发性内分泌腺瘤病I型的家系研究

目的对1例多发性内分泌腺瘤病I型（MEN1）患者进行基因诊断和家系成员的随访。方法收集MEN1患者的临床及家系资料,抽取先证者及5位家系成员外周血提取DNA,对MEN1基因的10个外显子进行PCR扩增,用全自动测序仪进行测序分析。结果（1）经MEN1基因突变检测证实,先证者存在内含子5剪切位点的突变（IVS7+2 T→G）。（2）先证者无临床表现的儿子也携带此突变,在基因诊断7个月后出现了明显的临床表现,术后病理证实为胰岛β细胞瘤和左肾上腺腺瘤。结论临床医师应常规对所有MEN1患者及其家系高危成员尽早进行基因突变分析和筛查,并严格随访,从而改善疾病的预后。     

同一等位基因复合杂合突变导致Ⅰ型遗传性抗凝血酶缺陷症

目的对1例遗传性抗凝血酶（AT）缺陷症先证者及其家系进行表型诊断和基因诊断。方法采用免疫比浊法和发色底物法分别检测先证者及其家系成员的AT抗原（AT：Ag）和AT活性（AT：A）,抽提外周血基因组DNA,PCR扩增AT基因（SERPINC1）7个外显子及其侧翼序列,应用直接测序法对先证者进行AT基因序列分析。针对先证者中发现的突变位点,对其家系成员进行相应基因突变检测,同时在100例正常人中筛查以排除多态性。结果先证者AT：Ag和AT：A分别为114 mg/L和54.8%。其AT基因外显子2区发现了2个杂合点突变,分别为c.134G〉A和c.342T〉G。其家系部分成员检测到相应的杂合突变。家系遗传分析表明,2个杂合突变位于同一等位基因。结论同一等位基因复合杂合突变是导致该家系Ⅰ型遗传性AT缺陷症的分子原因。     

Germline RET mutations in exons 10 and 11: an Iranian survey of 57 medullary thyroid carcinoma cases

The susceptibility gene for hereditary Medullary Thyroid Carcinoma (MTC) is the RET proto-oncogene. The aim of this study was to evaluate the prevalence of common germline RET mutations in exons 10 and 11 among Iranian MTC patients. Fifty-seven non-related MTC patients were examined in this study (Females: Males =1.2:1.0, Mean age = 40.0 +/- 11.5 years) and the existence of mutations was assessed through the PCR-RFLP technique. The only Multiple Endocrine Neoplasia type 2A (MEN2A) patient displayed a C634W mutation in exon 11. Among 53 apparently sporadic MTC patients, one patient showed a C620R mutation in exon 10 and two other patients displayed C624Y mutations in exon 11 of RET proto-oncogene. Neither the only Multiple Endocrine Neoplasia type 2B (MEN2B) patient nor two Familial MTC patients was found to carry germline mutations in exons 10 and 11. This study reports, for the first time, the prevalence of common RET mutations among Iranian, apparently sporadic MTC patients, underlining the critical importance of screening for RET mutations in such patients.     

RET基因C634Y突变致多发性内分泌腺瘤病2A型一例报道并文献复习

多发性内分泌腺瘤病2A型（MEN2A）是多发性内分泌腺瘤病2型（MEN2）的一种,临床通常表现为甲状腺髓样癌（MTC）、嗜铬细胞瘤（PHEO）及甲状旁腺功能亢进。研究表明MEN2A由10号染色体RET基因突变导致。本文报道了一例由RET基因C634Y突变导致的MEN2A患者,并对其家族成员进行了基因检测,绘制系谱图。基因检测结果显示患者同胞及同胞的子女存在C634Y突变。通过本病例诊疗结合文献复习,提示临床当患者出现内分泌腺体肿瘤时,需引起警惕,应对患者其他内分泌腺体进行进一步检查,并进行RET基因检测,以防出现误诊、漏诊,实现早期治疗,提高治疗效果,改善患者预后。MEN2A患者亲属也应进行RET基因检测。     

多发性内分泌腺瘤2A型家系筛查和RET基因突变研究

目的 探讨多发性内分泌腺瘤2A型（MEN2A）的临床诊治特点及RET基因检测的意义.方法 对1976年6月至2013年2月间诊治的1个MEN2A家系共21例家庭成员进行系统家系调查,提取外周血进行RET基因和血清基础降钙素（Ct）水平检测.结果 基因检测家系内共10例家庭成员存在RET基因第11外显子p.C634Y 突变（10/21）,与临床完全符合.10例MEN2A患者中,男8例,女2例.7例甲状腺髓样癌（MTC）首次平均诊断年龄34.3（21-55）岁;肿瘤平均最大直径2.8（0.8-3.7）cm,5例接受了不规范的甲状腺切术,2例接受双侧甲状腺切除＋改良的双侧颈部淋巴结清扫,其中1例同期伴发甲状腺乳头状癌.平均随访172.4（10-440）个月,术后4例血清Ct水平升高,3例正常.7例中3例伴发双侧肾上腺嗜铬细胞瘤（PHEO;2例同时,1例异时）,平均首次诊断年龄48.3（42-58）岁,肿瘤平均最大直径7.0（4.4-8.5）cm;均接受了保留肾上腺皮质功能的PHEO切除术.分别随访15、17、120个月,未发生肾上腺皮质功能低下和复发、转移.通过家系调查发现的其中3例无症状RET基因突变携带者,平均年龄11.7（8-15）岁,均已随访17个月,Ct水平仍均轻度升高,均拒绝手术.结论 提高对MEN2A的认识和认知水平,整合临床筛查和RET基因检测,有利于MEN2A的及早诊断和规范化治疗,可减少手术并发症和提高远期治愈率.     

RET oncogene mutations in medullary thyroid carcinoma in Mexican families

BACKGROUND: Different RET oncogene mutations have been found to be associated with inherited medullary thyroid carcinoma (MTC) in the context of three different syndromes including multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC). These mutations have been recorded in different populations, but to date there is no corresponding study in Mexican families. Our purpose was identification of RET mutations in Mexican families with inherited or sporadic MTC (SMTC) and search for RET protein expression as prognostic marker in MTC tumors. METHODS: Nine unrelated families with MTC corresponding either to two MEN 2A, three MEN 2B, or four SMTC were studied. Screening of exons 10, 11, and 13-16 of RET oncogene in DNA from circulating lymphocytes and tumor samples were analyzed. Immuno- staining for RET was performed in the corresponding tumor. RESULTS: Germline 918 ATG-->ACG RET mutation was present in three unrelated MEN 2B individuals and corresponding somatic mutation in one individual with SMTC; 634 TGC-->TTC RET mutation was detected in two related patients in an MEN 2A family and the 634 TGC-->TAC RET mutation was detected in 12 related individuals from a second MEN 2A family. RET protein expression was detected in all MTC tumors showing different staining intensity. CONCLUSIONS: RET mutations found in Mexican patients with MTC are similar to those previously reported in several MTC families worldwide. This indicates that RET mutations are highly conserved and that MTC etiology does not depend to a great extent on environmental factors or ethnic differences. Detection of RET protein in MTC tissue sections is not useful as prognostic marker.     

Ret-proto-oncogene analysis in medullary thyroid carcinoma

Introduction: Medullary carcinoma of the thyroid (MTC) is a rare tumour which occurs in both sporadic and hereditary forms. Mutations of the RET proto-oncogene have been identified in hereditary forms. The aim of our study was to confirm or exclude familial disease by examining for germline mutations in the RET proto-oncogene in patients with medullary thyroid carcinoma. Methods: Nine patients with medullary thyroid carcinoma and 4 of their children were studied. Peripheral blood was used to examine for mutations in the RET proto-oncogene. When this was not available, archival thyroid tissue was used. Results: Seven patients had clinically sporadic tumours, confirmed by mutational analysis of RET. Four children were at risk of being carriers of a mutated gene, as their fathers had histologically proven MTC and had tested positive for the mutation at codon 618 on exon 10 of the RET proto-oncogene. Three of these children carried the 618 mutation. To date, 2 have had a prophylactic thyroidectomy, the pathology of which revealed C-cell hyperplasia. One child had familial disease excluded by mutational analysis. One patient had a clinical diagnosis of MEN2B confirmed by detection of the 918 mutation on exon 16 of the RET proto-oncogene. Conclusions: RET proto-oncogene analysis is a reliable method of differentiating familial from sporadic MTC. Mutational information determines which family members of affected kindreds are at risk of developing the disease and can be used to affect clinical management.     

多发性内分泌腺瘤2A 型家系的临床筛查及预防性甲状腺全切除术

目的：探讨多发性内分泌腺瘤2A型（multiple endocrine neoplasia type 2A,MEN 2A）家系筛查的临床意义和进行预防性甲状腺全切除的可行性和有效性。方法对一个MEN 2A家系行家系调查,提取外周血行RET原癌基因和降钙素检测,并对无症状的基因突变携带者行预防性甲状腺全切除术。结果基因检测该家系为RET原癌基因第11外显子第634位点TGC→CGC杂合错义突变,即p．C634R突变,与MEN 2A患者临床表型-甲状腺髓样癌（ medullary thyroid carcinoma ,MTC）或MTC伴肾上腺嗜铬细胞瘤（ pheochromocytom ,PHEO）完全共分离。6例MEN 2A中,男4例,女2例;首次诊断平均年龄33.5（19～65）岁;MTC平均直径2.3（0.7～5.2）cm。其中3例以颈部占位或伴腹泻就诊,接受了不规范的甲状腺切除术或＋双侧Ⅵ区淋巴结清扫或＋侧颈部淋巴结清扫;T2N1bM02例,T3N1bM01例。3例无症状者中2例行预防性甲状腺切除＋双侧Ⅵ区淋巴结清扫,另1例行双侧甲状腺全切除＋双侧Ⅵ区淋巴结清扫＋右侧颈淋巴结清扫术;T1N0M02例,T1N1bM01例。仅见1例无症状者伴发左侧PHEO（1/6）并优先于MTC接受了左侧PHEO切除。6例术后4例降钙素仍升高,其中有症状中的1例（ T3N1bM0）先后接受了4次颈部手术,仍于首次术后130个月出现多处骨转移伴骨痛（T3N1bM1）,服用范得他尼2个月后骨痛消失,至今带瘤生存32个月;另外有症状和无症状者各1例（T2N1bM0和T1N1bM0）,分别在首次术后6、7个月接受了再次手术,包括另1例未再次手术的有症状者（T2N1bM0）,3例至今分别已22、22和20个月,降钙素仍升高。其余2例无症状患者（T1N0M0）术后已随访20个月,降钙素均＜2.0 ng/L。结论对MEN 2A家系进行临床筛查,有利于早期诊断和治疗,改善预后;术前整合RET基因和降钙素检测,对无症状基因突变携带者进行预防性全甲状腺切除是可行、有效的。