成人经典型Bartter综合征家系CLCNKB基因突变的研究

目的 分析1个成人经典型Bartter综合征家系CLCNKB基因突变特点。 方法 用PCR方法对先证者CLCNKB基因19个外显子及侧翼序列进行扩增,PCR产物纯化后直接测序或构建T-A克隆测序检测其基因变异。 结果 先证者CLCNKB基因表现为G433E和cDNA 753delG复合杂合突变。家系分析表明,杂合错义突变G433E来自父亲,杂合缺失突变cDNA 753delG来自母亲。患者弟弟携G433E,其妹妹正常。正常对照100条染色体中未发现同样变异。 结论 在1个成人迟发经典型Bartter综合征家系中发现了CLCNKB基因2个突变位点,经检索文献及人类基因突变库（HGMD）,cDNA 753delG为新发现突变位点。     

一个Liddle综合征家系上皮钠通道基因突变的研究

目的：对1个Liddle综合征家系成员进行基因突变分析。方法：1个3代均有高血压患者的家系中，1例14岁的成员临床诊断为Liddle综合征。抽取所有存活家系成员的外周血基因组DNA，PCR扩增上皮钠通道β亚单位基因（βENaC)和γ亚单位基因（γENaC)第13外显子，产物直接DNA测序进行基因突变检测。结果：βENaC基因第13外显子的DNA经双向测序显示，先证者及另两例家系成员第616号密码子均存在CCC－TCC（Pro-Ser)杂合错义突变，并且第632号密码子存在GAC－CAC（Asp-His)的变异与之连锁。对150例无关个体进行直接测序未发现GAC－CAC变异，证明这是一新的突变。其他家系成员均未发现这一基因突变，另2例基因突变的成员的临床生化检验结果符合Liddle综合征；所有家系成员中未检测到γENaC基因第13外显子的突变。结论：对临床诊断的Liddle综合征患者及其家属，进行基因突变检测有助于早期筛选出家系中的其他患者。该家系中，第632号密码子检测到一新的突变GAC－CAC（Asp-His)，通过表型分析认为这一新突变有可能与Liddle综合征有关。     

VHL基因N131Y突变导致家族性胰腺多发囊肿

目的探讨1个单纯表现胰腺多发囊肿的Von Hippel-Lindau(VHL)综合征家系的VHL基因变异情况。方法调查1个VHL病家系临床资料,绘制树状图;抽取该家系3位成员外周血,提取基因组DNA,应用聚合酶链式反应(PCR)以及实时定量PCR对VHL基因进行点突变以及基因缺失进行筛查。结果该家系中仅先证者和其母亲表现为胰腺多发囊肿,且基因检测结果显示先证者和其母亲均存在VHL基因编码区第391位核苷酸A突变为T,导致第131号编码氨基酸由天冬酰胺变成了酪氨酸,为VHL基因未曾报道过的突变位点;而其父亲均无异常表现。结论 VHL综合征中,VHL基因2号外显子发生该位点突变,则仅表现为胰腺多发囊肿;对于单纯表现为胰腺多发囊肿的患者,尤其是青年或无胰腺疾病家族史者需考虑VHL综合征的可能。     

迟发性家族性局灶节段肾小球硬化的足细胞分子基因突变研究

目的 了解迟发性家族性局灶节段肾小球硬化（FSGS）的足细胞分子基因致病突变特点。 方法 研究对象为上海瑞金医院肾脏科1997年9月至2007年10月收集的31个迟发性家族性FSGS家系。诊断标准：（1）成员年龄大于12岁；（2）1个家系中有2例或2例以上患者经肾活检证实为FSGS，或家系成员中有1例肾活检证实为FSGS，另有1例成员有蛋白尿或肾功能不全。100例健康人为对照组。外周血基因组DNA 经PCR扩增后直接对NPHS2、ACTN4、TRPC6基因行测序分析。 结果 发现ACTN4基因新错义突变L316P，该家系患病成员起病年龄平均（38.7±7.4）岁，肾功能损害进展相对缓慢，家系3例患病成员均为突变杂合子。发现TRPC6基因新杂合错义突变Q889K，该家系患者起病年龄平均（38.0±4.2）岁，肾功能损害进展也较缓慢，家系中临床表现存在个体差异，家系中3例患病成员均为突变杂合子。发现TRPC6静止突变G467G。所有家系中未发现NPHS2致病突变。健康对照组200条染色体亦未发现以上突变。 结论 在31例迟发性FSGS家系中发现2个家系携带致病相关突变：ACTN4新突变L316P和TRPC6新突变Q889K。在中国人群家族性迟发性FSGS中，ACTN4及TRPC6基因突变是致病原因之一，尚未发现NPHS2相关致病突变。     

瘢痕疙瘩家系外周血Smad2基因的突变检测

目的 对一瘢痕疙瘩家系进行Smad2基因的突变检测,以明确Smad2基因突变是否与这一家系发病有关.方法 以瘢痕疙瘩家系中4个患者的瘢痕疙瘩组织及其周围正常皮肤、外周血为研究对象,以其配偶的外周血为正常对照,采用PCR及基因序列分析,对所有标本的Smad2基因的所有外显子进行突变检测.结果 基因测序在所有标本中Smad2基因的1～11外显子及其邻近内含子均未发现突变.结论 此瘢痕疙瘩家系的致病基因,可能不是Smad2基因.     

脆性X染色体综合征一家系分析

目的:探讨脆性X染色体综合征(FXS)家系患者包括生殖在内的若干临床表现及其遗传学特征。方法:通过问诊、睾丸超声检查、精液分析、生殖激素水平测定、外周血核型检查、Y染色体微缺失检查等手段收集1例FXS家系的临床资料,采用Southern印迹测定该家系多个成员X染色体长臂脆性X智力低下-1(FMR1)基因的CGG三联重复序列的大小,确定其FMR1基因的状态(正常、前突变、全突变)并绘制家系图谱。结果:1经FMR1基因突变检测,该家系4代共34例成员中有3男1女系FMR1全突变患者,占家系成员的11.76%;有9女系FMR1前突变患者,占家系成员的26.47%。2包括先证者在内的2例全突变FXS男性患者睾丸体积30 ml,精子浓度高(250×10~6/ml),平均精子活力为50.5%,正常形态精子百分率为17.5%,精子核DNA碎片率指数(DFI)为18.5%;生殖激素仅示睾酮低下;外周血染色体核型未见异常,Y染色体也未见缺失。3Ⅱ代4例前突变女性患者中有1例患有卵巢早衰(POF),3例患有子宫肌瘤。结论:该家系中部分FXS男性患者表现为巨睾症和多精子症,其余精子参数正常;在世代传递中前突变患者可扩展为全突变,且男性的全突变风险高于女性,对于80的CGG三联重复序列前突变患者,其突变遗传给后代及前突变扩展为全突变的风险会有所增加。建议有生育要求者接受基因检测、临床指导和遗传咨询,必要时行产前诊断与植入前胚胎学诊断。     

四例脂蛋白肾病患者载脂蛋白E基因突变筛查

目的 通过对4例脂蛋白肾病患者及家系成员载脂蛋白E(apoE)基因的分析， 研究脂蛋白肾病的发病机制。 方法 调查患者家系情况，对其中2例患者的家系成员进行尿常规筛查及血肌酐、血脂和血清脂蛋白的检测。PCR法扩增4例患者apoE基因的外显子， DNA测序， 发现突变后，寻找限制性内切酶酶切位点。使用聚合酶链反应-限制性酶切片段长度多态性(PCR-RFLP)的方法筛查正常对照及其家系成员。 结果 4例脂蛋白肾病患者中有2例携带杂合的apoE基因缺失突变 (142-144-0)，2例患者携带杂合的apoE点突变 (Arg25Cys)，2种突变均可见于尿液检查正常的亲属，并均表现为apoE升高。 结论 4例脂蛋白肾病的患者中发现两种apoE基因的突变，apoE Arg25Cys和apoE(142-144-0)。结合既往的研究结果，apoE(142-144-0)同时见于5例(本研究2例，前期研究3例)患者，为中国脂蛋白肾病患者常见的致病性基因突变。患者家系成员中的携带者可以不表现出肾脏病。     

先天性小睑裂综合征的病因及诊疗进展

先天性小睑裂综合征是一种少见的常染色体显性遗传疾病,典型的临床表现为睑裂狭窄、上睑下垂、倒向型内眦赘皮和内眦间距增宽四联症;除了眼睑畸形外,尚可并存其他系统疾病。其主要致病基因为FOXL2,定位于3号染色体长臂2区3带。由于多种畸形并存,手术修复治疗面临很大挑战。现就近年来该病在病因、临床表现和手术治疗等方面的研究进展作一综述。     

局灶节段性肾小球硬化患者致病基因突变检测

目的对散发性或家族性局灶节段性肾小球硬化（focal segmental glomerulosclerosis,FSGS）患者进行FSGS致病基因热点突变进行筛查,了解这些热点突变在我国FSGS患者的发生情况。方法研究对象为我院经肾脏活检确诊的40例FSGS散发病例及一个22人的FSGS家系LF-01。收集散发病例的外周血,采用盐析法提取基因组DNA;对LF-01家系进行调查,收集实验室检测数据,并留存外周血提取基因组DNA。对40例散发病例及所有家系成员进行ACTN4第8外显子,TRPC6第2、5、12、13外显子和INF2基因2、3、4外显子筛查,通过PCR扩增外显子后,直接测序进行基因突变检测。结果LF-01家系共9人为患病或可能患病状态,该家系表现为不完全外显遗传模型。40例散发FSGS患者,平均发病年龄37岁,男女比例为26：14,其中22例患者临床表现为肾病综合征。我们对所有样本进行了ACTN4第8外显子,TRPC6第2、5、12、13外显子和INF2基因2、3、4外显子筛查,均未发现有已知的基因突变。结论国外报道的FSGS致病基因的热点突变ACTN4、TRPC6和INF2可能不是中国汉族人群FSGS的致病基因。     

国人黑斑息肉病LKB1基因胚系突变的检测

目的　研究国人家族性黑斑息肉病患者LKB1基因胚系突变情况。　方法　对确诊的4个黑斑息肉病家系取血 ,提取基因组DNA ,用PCR方法扩增每个家系中 2例患者和 1名正常成人的LKB1的 9个外显子 ,以单链构象多态性方法检测 ,对可疑突变者测序。无异常的家系再对全部编码序列测序。　结果　 4个家系中 2个家系有第 84 2位胞苷酸 (C)缺失 ,引起LKB1基因移码突变 ,产生截短蛋白。另 2个家系未见LKB1外显子序列异常。　结论　LKB1基因胚系突变是本病重要的分子遗传学基础 ,第 84 2位C缺失可能是具有中华民族特点的突变热点和始祖突变。     

Phenotypic expression of a family with multiple endocrine neoplasia type 2A due to a RET mutation at codon 618

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN2A) is caused by missense mutations in the RET proto-oncogene on chromosome 10. This paper reports the phenotypic expression of a family with MEN2A, in which serine substitutes for cysteine at codon 618 in exon 10 of the RET gene. It was first claimed that medullary thyroid cancer (MTC) with this rare mutation led to mild disease; this has recently been updated to intermediate-high risk, based on stratified genetic information. METHODS: The family was mapped over six generations. In 1971 family members were invited to join a screening programme. Genetic testing was started in 1994. RESULTS: Twenty-two individuals with MTC were identified, 16 by the screening programme. One screened patient had a phaeochromocytoma and four had hyperparathyroidism. At surgery for MTC 12 patients had local tumour metastases and two young patients also had liver metastases. No screened patient died from MTC during a mean observation time of 19 years. Six other family members were diagnosed with MTC by signs and symptoms, five of whom died from MTC. CONCLUSION: Because of the great interindividual differences in tumour aggressiveness within the family it is impossible to predict whether an individual gene carrier will have an aggressive MTC or not. This unpredictability is an additional argument, besides those obtained in stratified genetic studies, for operating on gene carriers at young age.     

Clinical characterization of a family with a mutation in the uromodulin (Tamm-Horsfall glycoprotein) gene

BACKGROUND: We have recently identified a mutation in the uromodulin gene in a large family affected with hyperuricemia, gout, and renal failure. The purpose of this investigation is to provide a comprehensive characterization of the clinical findings of this syndrome in family members who had a mutation in the uromodulin gene. METHODS: An extended family suffering from hyperuricemia and gout was identified by a local practitioner. After consent was obtained, patients provided a directed clinical history and blood and urine specimens for chemical and genetic testing. All family members were tested for the presence of uromodulin gene mutations by direct DNA sequence analysis. The clinical and biochemical characteristics of family members carrying the affected mutation were then investigated. RESULTS: Thirty-nine family members were found to have an exon 5 uromodulin gene mutation (g.1966 1922 del), and 29 unaffected family members were identified. The cardinal clinical features in individuals with the uromodulin mutation included hyperuricemia, decreased fractional excretion of uric acid, and chronic interstitial renal disease leading to end-stage renal disease (ESRD) in the fifth through seventh decade. Women did not always develop hyperuricemia or gout, but still developed progressive chronic renal failure. CONCLUSION: Mutation of the uromodulin gene resulted in hyperuricemia, reduced fractional excretion of uric acid, and renal failure. Genetic testing will be required to definitively identify individuals suffering from this condition. We are interested in studying other families that may suffer from this condition and would appreciate any such referrals.     

Comprehensive genetic and endoscopic evaluation may be necessary to distinguish sporadic versus familial adenomatous polyposis-associated abdominal desmoid tumors

BACKGROUND: There are limited data regarding how many patients with desmoid tumors actually represent cases with underlying familial adenomatous polyposis. METHODS: A proband presenting with desmoid tumors and several of the family members underwent a detailed family history, genetic (adenomatous polyposis coli [APC] gene sequencing), and upper and lower endoscopic evaluation. RESULTS: The proband's initial diagnosis was of a sporadic desmoid tumor. Colonoscopy was entirely normal. However, on subsequent esophagogastroduodenoscopy, several gastric polyps were found. The proband's mother subsequently underwent colonoscopy and was found to have multiple colon adenomas. On genetic analysis, a deletion of "T" was identified at codon 2645 of the APC gene in the proband. The proband's mother had a normal APC protein truncation test result. However, on full gene sequencing, the mother was found to harbor the same APC gene mutation. CONCLUSION: A detailed family history and endoscopic and genetic evaluations for patients with desmoid tumors are vital because they may be the sentinel presentation of familial adenomatous polyposis. If confirmed in larger studies, APC full gene sequencing and upper and lower gastrointestinal tract evaluation may need to be part of standard evaluation of patients with abdominal desmoid tumors.     

Detection of renal dysfunctions in family members of patients with Balkan endemic nephropathy

BACKGROUND/AIM: Recent studies have questioned whether new cases of Balkan endemic nephropathy (BEN) are occurring. The aim of the present study was to find out whether new members with renal dysfunctions can be identified among family members of BEN patients from the Kolubara region. METHODS: The study included 47 family members of 5 BEN patients on hemodialysis (HD) and 17 members of 3 non-BEN patients on HD. Their medical and epidemiological histories were taken, an objective survey made, and all persons were examined for global and tubular kidney function. RESULTS: Seven BEN family members (2 with previously known BEN) had creatinine clearance (Ccr) below the 75th percentile rank according to sex and age. All non-BEN family members had normal Ccr and no evidence of previous renal disorders. Hypertension was found in 20 (43%) BEN and 6 (35%) non-BEN family members. No significant differences in the frequency of renal function disorders (proteinuria, alpha1-microglobulinuria, urine specific gravity, osmolality, functional excretion of sodium, tubular phosphate resorption) or anemia were found between the groups. Renal disorders were detected in 18 BEN family members without previously detected disease, 3 of whom fulfilled criteria for a diagnosis of BEN and another 2 for BEN-suspected persons. CONCLUSION: New cases of BEN are still arising among the affected families in the Kolubara region.     

Exclusion of mutations in FXYD2, CLDN16 and SLC12A3 in two families with primary renal Mg2+ loss.

BACKGROUND: Based on genetic studies in families with hereditary renal Mg(2+) reabsorption disorders, several genes were shown to be involved in renal Mg(2+) transport. Mutations in the CLDN16 gene were found to underlie autosomal recessive hypomagnesaemia associated with hypercalciuria and nephrocalcinosis. The FXYD2 gene was implicated in autosomal dominant renal Mg(2+) wasting associated with hypocalciuria. Mutations in the SLC12A3 gene, also known as NCC, cause Gitelman's syndrome. In addition to hypokalaemic metabolic alkalosis, hypomagnesaemia associated with hypocalciuria is considered to be a hallmark feature of this latter disorder. METHODS: We have characterized a new family with presumed dominant renal hypomagnesaemia by detailed clinical examination and mutation analysis of CLDN16, FXYD2 and SLC12A3. In addition, we have performed mutation analysis of these three genes in a previously described family with autosomal recessive renal Mg(2+) wasting. In this family, linkage analysis was performed with polymorphic markers in the vicinity of the FXYD2 gene. RESULTS: The phenotype of the new family closely resembles that of the known dominant families with a mutation in FXYD2, but mutations in this gene were not identified in the new family. No mutations were found in CLDN16 and SLC12A3 either. Sequencing of the three genes in the patients of the recessive family revealed no mutations. In addition, haplotype analysis excluded linkage to the FXYD2 region on chromosome 11q23. CONCLUSION: Our results indicate that, in addition to the currently known loci involved in renal Mg(2+) handling, at least one other gene must be involved.     

Familial relapsing haemolytic uraemic syndrome and complement factor H deficiency.

BACKGROUND: In a recent study of three families we have found that inherited haemolytic uraemic syndrome (HUS) maps to a region of chromosome 1q containing the gene for complement factor H. In one of these families and also in a case of sporadic D-HUS, we have identified mutations in the factor H gene. A further family with inherited HUS has therefore been investigated. METHODS: DNA extracted from the family members and DNA extracted from archival post-mortem material from a deceased family member, was studied. Review of renal biopsies and study of complement components was also undertaken. RESULTS: This family demonstrates an inherited deficiency of complement factor H. Non-diarrhoeal HUS has affected at least two family members with half normal levels of factor H. CONCLUSION: These findings represent further evidence of the association between factor H dysfunction and HUS.     

Non-urate transporter 1-related renal hypouricemia and acute renal failure in an Israeli–Arab family

Idiopathic renal hypouricemia (IRHU) is a rare hereditary disease, predisposing the individual to exercise-induced acute renal failure (EIARF) and nephrolithiasis, and it is characterized by increased clearance of renal uric acid. Most of the described patients are Japanese, who have loss-of-function mutations in the SLC22A12 gene coding for the human urate transporter 1 (URAT1) gene. An 18-year-old youth, who was admitted for EIARF due to IRHU, and six consanguineous Israeli–Arab family members were included in the study. The family members were tested for fractional excretion of uric acid and molecular analysis of the URAT1 gene. Four family members, including the proband, had very low levels of blood uric acid and high rate of fractional excretion (FE urate> 100%) of uric acid. Genetic analysis of the affected family members did not reveal a mutation in the coding regions and intron–exon boundaries of SCL22A12. Haplotype analysis excluded SCL22A12 involvement in the pathogenesis, suggesting a different gene as a cause of the disease. We herein describe the first Israeli–Arab family with IRHU. A non-URAT1 genetic defect that causes decreased reabsorption or, more probably, increased secretion of uric acid, induces IRHU. Further studies are required in order to elucidate the genetic defect. Hilla Bahat and Dganit Dinour contributed equally to the work.     

FOXL2 is a sensitive and specific marker for sex cord-stromal tumors of the ovary

Sex cord-stromal tumors (SCSTs) of the ovary are relatively uncommon tumors. Diagnosis of SCST rests primarily on the histomorphology of these tumors, and tumors with an atypical or unconventional appearance can pose diagnostic challenges. Previously, we had identified FOXL2 (402C→G) mutation as being characteristic of adult granulosa cell tumors (aGCTs). However, molecular screening for this mutation is not always possible and adds time and cost to the diagnostic process. In this study, we investigated the potential diagnostic use of immunostaining for FOXL2 on formalin-fixed paraffin-embedded tissue sections. Using a commercially available polyclonal antiserum against FOXL2 protein, immunoexpression of FOXL2 was tested in 501 ovarian tumor samples, including 119 SCSTs, using whole tissue sections and tissue microarrays. Staining was correlated with FOXL2 mutation status. In addition, we compared FOXL2 immunoexpression with that of α-inhibin and calretinin, the 2 traditional immunomarkers of SCST, in a subset of 89 SCSTs. FOXL2 immunostaining was present in 95 of 119 (80%) SCSTs, including >95% of aGCTs, juvenile granulosa cell tumors, fibromas, and sclerosing stromal tumors. Only 50% of Sertoli-Leydig cell tumors (N=40) expressed FOXL2. One of 11 steroid cell tumors and 3 of 3 female adnexal tumors of probable Wolffian origin showed FOXL2 immunoreactivity, whereas all other non-SCSTs tested (N=368) were negative for FOXL2 expression. Thus, the sensitivity and specificity of FOXL2 immunoreactivity for SCST are 80% and 99%, respectively. The FOXL2 (402C→G) mutation was confirmed to be both a sensitive and relatively specific indicator of aGCT. Forty-five of 119 SCSTs were mutation positive. These cases were 39 of 42 (93%) aGCTs, 3 of 40 Sertoli-Leydig cell tumors, 2 of 5 thecomas, and 1 of 4 (25%) SCSTs of unclassified type. SCSTs harboring a FOXL2 mutation consistently immunoexpressed FOXL2 (44 of 45, 98%), but FOXL2 immunostaining was also seen in many SCSTs that lacked a mutation (49 of 73, 67%). FOXL2 immunostaining showed higher sensitivity for the diagnosis of SCST, compared with α-inhibin and calretinin, and FOXL2 staining was typically more intense in positive cases compared with either α-inhibin or calretinin. In the SCSTs that were negative for FOXL2 expression, α-inhibin and/or calretinin immunostaining yielded positive results. In conclusion, FOXL2 is a relatively sensitive and highly specific marker for SCST. FOXL2 staining is present in almost all SCSTs with a FOXL2 mutation, and also in a majority of SCSTs without a mutation. FOXL2, together with α-inhibin and calretinin, forms an immunomarker panel that will result in positive staining with 1 or more markers in essentially all cases of SCST.