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。     

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.     

突变位点c.868C>T年轻的成年发病型糖尿病1型家系一例报道

报道1例突变位点为c. 868C>T,p. Arg290Cys的MODY1家系，分析其临床特点及分子遗传学特征。先证者使用目标序列捕获高通量测序技术检测致病基因，发现其携带肝细胞核因子4α基因突变，收集家系成员外周血基因组DNA，使用Sanger测序技术均检测到同一突变位点c. 868C>T的杂合变异。根据检测结果调整治疗方案，从而提高患者血糖达标率。     

5个青少年起病的成人型糖尿病2型家系的临床及遗传学分析

目的探讨青少年起病的成人型糖尿病2型(MODY2)患者的临床及分子遗传学特征。方法收集西安市儿童医院内分泌遗传代谢科近2年诊断的5例MODY2患者及其家系成员的临床资料和实验室检查结果。对所有先证者行全外显子组基因检测, 筛选出的变异位点在各家系中行Sanger测序验证。结果 5个先证者中除先证者4有多饮多尿表现外, 其余患儿的高血糖均为意外发现。所有先证者尿常规、尿蛋白五项及血脂均无异常, HbA1C 5.96%～8.15%。不同于以往MODY2患者, 本研究发现先证者5同时存在胰岛素抵抗。基因检测证实5个家系均存在葡萄糖激酶(GCK)基因突变, 共包含4种突变类型:c.146C>T(p.T49I)、c.1237T>G(p.Y413D)、c.683C>T(p.T228M)及c.952G>T(p.G318W)。c.1237T>G(p.Y413D)及c.952G>T(p.G318W)为尚未报道的新突变。给予所有先证者生活方式干预, 血糖控制相对平稳。结论 MODY2可能合并胰岛素抵抗;该病治疗可仅给予生活方式干预, 效果良好;本研究发现的GCK基因2个...     

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。     

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。     

一个新的葡萄糖激酶基因-E339K突变导致的中国人青少年发病的成年型糖尿病2型家系

目的 寻找一个典型的青少年发病的成年型糖尿病2型(MODY2)家系的责任基因.方法 抽提MODY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 在MODY2家系中确认了一个新型的GCK-E339K突变,该突变与糖尿病或糖耐量异常共分离.结论 GCK-E339K突变可能与该MODY2家系相关,是该MODY2家系的责任基因.     

葡萄糖激酶基因杂合突变致新生儿糖尿病一例报告并文献复习

回顾分析一例由葡萄糖激酶(GCK)基因杂合突变所致新生儿糖尿病(NDM)的临床资料和分子遗传学特征。仅予饮食干预后随访末稍血糖:FBG 6.5~8.6 mmol/L、餐后血糖(PBG)7.1~11.3mmol/L,FIns 2.12~10.74 mIU/ml,FC-P 1.2~1.5 ng/ml,HbA_1c 6.8%。调查患儿家系14名,发现4例糖尿病患者(患儿的姨母和母亲:GDM和糖尿病;外祖父和祖父:糖尿病),患儿及其母亲存在GCK基因c.1190GT(p.Arg397Leu)杂合突变,其父亲和双胎妹妹未见基因突变。GCK基因杂合突变引起NDM还是MODY2还需进一步结合临床和基因检查鉴别,对于NDM患儿,尤其是有糖尿病家族史者,基因检测对病因诊断尤为重要。     

对一例Gitelman综合征伴反复自然流产患者的基因分析

采用Sanger测序技术对1例伴有反复自然流产的Gitelman综合征可疑患者及其父母进行SLC12A3基因遗传学分析。结果显示,先证者存在SLC12A3基因复合杂合突变(c.1077C>G,c.2890C>T),引起氨基酸序列改变(p.N359K,p.R964W)。家系成员中母亲携带c.1077C>G(p.N359K)杂合变异,父亲携带c.2890C>T(p.R964W)杂合变异。提示Gitelman综合征患者因内环境失衡、复杂激素改变和电解质紊乱等可能造成不良妊娠结局,应加强妊娠期管理。     

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。     

Mutations in GCK and HNF-1alpha explain the majority of cases with clinical diagnosis of MODY in Spain

OBJECTIVE: The aim of this study was to group patients with MODY (maturity-onset diabetes of the young) according to the genetic alterations underlying the disease and to investigate their clinical characteristics. PATIENTS AND METHODS: Molecular analysis of GCK (MODY2), HNF-1alpha (MODY3), HNF-4alpha (MODY1) and HNF-1beta (MODY5) genes was performed by DNA sequencing in 95 unrelated index probands (47M/48F; mean age 9.9 +/- 5.2 years) with clinical diagnosis of MODY. After classification into MODY subtypes according to the genetic alterations, clinical characteristics were compared between the groups. RESULTS: Seventy-six families were shown to carry mutations in GCK (34 of them previously unreported), eight families presented HNF-1alpha mutations, and a large genomic rearrangement in HNF-1beta was found in a family. No alteration was found in HNF-4alpha. Thus, relative frequencies in the group studied were 80% MODY2, 8.5% MODY3 and 1% MODY5. Comparison of clinical parameters according to genetic status showed significant differences between MODY2 and MODY3 patients in age at diagnosis (9.4 +/- 5.4 years vs. 12.7 +/- 4.6 years), diagnosis (impaired glucose tolerance vs. diabetes), diagnostic test used (OGTT vs. fasting glucose), treatment (diet and exercise vs. insulin/oral antidiabetic agents) and birth weight (2.96 +/- 0.44 kg vs. 3.40 +/- 0.67 kg). CONCLUSION: Almost 90% of the MODY cases in the group studied are explained by mutations in the major genes GCK (MODY2) and HNF-1alpha(MODY3), although differences in the relative prevalence of each form could be partly due to patient referral bias (paediatric vs. adult). In general, patients with MODY2 were diagnosed at an earlier age in life than MODY3 patients and had a milder form of diabetes. Moreover, the majority of patients with MODY2 mutations were treated with diet whereas half of MODY3 patients received pharmacological treatment.     

Nine novel mutations in maturity-onset diabetes of the young (MODY) candidate genes in 22 Spanish families

The aims of this study were to estimate the prevalence of major maturity-onset diabetes of the young (MODY) subtypes in Spanish MODY families and to analyze genotype-phenotype correlations. Twenty-two unrelated pediatric MODY patients and 97 relatives were screened for mutations in the coding region of the glucokinase (GCK), hepatic nuclear factor- HNF-1alpha and HNF4alpha genes using PCR-single strand conformation polymorphism and/or direct sequencing. In families carrying GCK mutations, the influence of genetic defects on fetal growth was investigated by comparing the birth weights of 32 offspring discordant for the mutations. Mutations in MODY genes were identified in 64% of the families. GCK/MODY2 mutations were the most frequently found, in 41%: seven novel (R369P, S411F, M298K, C252Y, Y108C, A188E, and S383L) and 2 already described mutations. Four pedigrees (18%) harbored mutations in the HNF-1alpha/MODY3 gene, including a previously unreported change (R271G). One family (4%) carried a novel mutation in the HNF-4alpha gene (IVS5-2delA), representing the first report of a MODY1 pedigree in the Spanish population. The age at diagnosis was prepubertal in MODY2 index patients and pubertal in MODY3 patients. Overt diabetes was rare in MODY2 and was invariably present in MODY3 index patients. Chronic complications of diabetes were absent in the MODY2 population and were present in more than 40% of all relatives of MODY3. Birth weight was lower in the presence of a GCK fetal mutation when the mutation was of paternal origin. The MODY1 patient was diagnosed at 15 yr of age. She developed intermittent microalbuminuria despite good metabolic control, and severe late-onset complications were common within her family. Mutations in the GCK/MODY2 gene are the most common cause of MODY in our population as recruited from pediatric and adolescent index patients. The inheritance of GCK defects by the fetus results in a reduction of birth weight. Clinical expression of MODY3 and MODY1 mutations, the second and third groups of defects found, was more severe, including the frequent development of chronic complications.     

Genetic epidemiology of MODY in the Czech republic: new mutations in the MODY genes <Emphasis Type="Italic">HNF-4α</Emphasis>, <Emphasis Type="Italic">GCK</Emphasis> and <Emphasis Type="Italic">HNF-1α</Emphasis>

AIMS/HYPOTHESIS: The aim of this study was to examine the prevalence and nature of mutations in HNF4alpha/MODY1, GCK/MODY2 and HNF-1alpha/MODY3 genes in Czech subjects with clinical diagnosis of MODY. METHODS: We studied 61 unrelated index probands of Czech origin (28 males, 33 females) with a clinical diagnosis of MODY and 202 family members. The mean age of probands was 22.7+/-12.0 years (range, 6-62) and the mean age at the first recognition of hyperglycaemia was 14.7+/-6.0 years (range, 1-25). The promotor and coding regions inclusive intron exon boundaries of the HNF-4alpha, GCK and HNF-1alpha genes were examined by PCR-dHPLC (HNF-1alpha and GCK) and direct sequencing. RESULTS: We identified 20 different mutations in the HNF-4alpha, GCK and HNF-1alpha in 29 families (48% of all families studied), giving a relative prevalence of 5% of MODY1, 31% of MODY2 and 11.5% of MODY3 among the Czech kindred with MODY. Three of 3, 10 of 11 and 1 of 6 of the mutations identified in HNF-4alpha, GCK and HNF-1alpha respectively, were new. CONCLUSION/INTERPRETATION: Of the families 48% carried mutations in the MODY1-3 genes and of the identified mutations 70% were new. In 52% of Czech families with clinical characteristics of MODY, no mutations were found in the analysed genes. This finding shows that the majority of MODY mutations in a central European population are local and that other MODY genes could be responsible for autosomal dominant transmission of diabetes mellitus.     

Mutations of maturity-onset diabetes of the young (MODY) genes in Thais with early-onset type 2 diabetes mellitus

Objective  Six known genes responsible for maturity-onset diabetes of the young (MODY) were analysed to evaluate the prevalence of their mutations in Thai patients with MODY and early-onset type 2 diabetes.
Patients and methods  Fifty-one unrelated probands with early-onset type 2 diabetes, 21 of them fitted into classic MODY criteria, were analysed for nucleotide variations in promoters, exons, and exon–intron boundaries of six known MODY genes, including HNF-4α , GCK , HNF-1α , IPF-1 , HNF-1β , and NeuroD1/β2 , by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method followed by direct DNA sequencing. Missense mutations or mutations located in regulatory region, which were absent in 130 chromosomes of non-diabetic controls, were classified as potentially pathogenic mutations.
Results  We found that mutations of the six known MODY genes account for a small proportion of classic MODY (19%) and early-onset type 2 diabetes (10%) in Thais. Five of these mutations are novel including GCK R327H, HNF-1α P475L, HNF-1α G554fsX556, NeuroD1 –1972 G > A and NeuroD1 A322N. Mutations of IPF-1 and HNF-1β were not identified in the studied probands.
Conclusions  Mutations of the six known MODY genes may not be a major cause of MODY and early-onset type 2 diabetes in Thais. Therefore, unidentified genes await discovery in a majority of Thai patients with MODY and early-onset type 2 diabetes.     

Genetic and clinical characterisation of maturity-onset diabetes of the young in Spanish families

OBJECTIVE: To investigate the frequencies of the major maturity-onset diabetes of the young (MODY) subtypes in a panel of Spanish families and to assess phenotypic differences in patients with the different subtypes of MODY. METHODS: Forty-eight subjects from twenty families with clinical diagnosis of MODY were studied. They underwent a standardised clinical examination and a 75-g oral glucose tolerance test (OGTT) was performed. Estimations of insulin sensitivity (%S) and insulin secretion capacity (%B) were calculated by the computer-solved homeostasis model assessment (HOMA). Mutations in the coding regions of hepatocyte nuclear factor (HNF)-4alpha/MODY1, glucokinase (GCK/MODY2) and HNF-1alpha/MODY3 genes were investigated by single strand comformation polymorphism and sequencing analysis. RESULTS: Mutations in the GCK and HNF-1alpha genes were observed in 5 (25%) and 7 (35%) families respectively. Novel mutations included R385X, M238fsdelT, V226fsdelTinsAA and S418-7del11 in the GCK gene, and S121fsdelC, V133M, R159Q and V259D in the HNF-1alpha gene. No MODY1 families were found. Subjects which were neither MODY2 nor MODY3 (MODY-X) had a higher fasting glucose than subjects in the other groups. Insulin secretion capacity was similar in the three groups and the insulin sensitivity was decreased in MODY-X subjects. Glucose levels were significantly higher and insulin levels significantly lower, throughout the OGTT, in MODY3 compared with MODY2 subjects. CONCLUSIONS: Mutations in the GCK/MODY2 and HNF-1alpha/MODY3 genes account for the majority of cases in a panel of Spanish MODY families, with MODY3 being the most frequent subtype. The relative frequencies and the clinical characteristics of these MODY subtypes are in agreement with data previously reported in other European populations. MODY-X patients seem to present a heterogeneous clinical profile.     

A novel nonsense mutation in GCK exon 9 co-segregates with diabetes phenotype.

Maturity-onset diabetes of the young is an autosomal dominant form of non-insulin dependent diabetes mellitus and is caused by mutations in at least six different genes. In the most common forms, i.e. MODY2 and MODY3, the glucokinase (GCK) and the hepatocyte nuclear factor (HNF)-1alpha gene is affected, respectively. We have screened the GCK gene and HNF-1alpha gene by direct sequencing in three German families with early onset type-2-diabetes, possibly MODY. Next to known polymorphisms we have identified two novel intronic insertions in GCK and a novel non-sense mutation in exon 9 (C364 X). The latter mutation has an autosomal dominant inheritance pattern. Accordingly, this novel mutation segregates with diabetes phenotype in this family.