Current understandings of the pathogenesis of type 1 diabetes:Genetics to environment

Type 1 diabetes(T1D)is an autoimmune disease that usually strikes early in life,but can affect individuals at almost any age.It is caused by autoreactive T cells that destroy insulin-producing beta cells in the pancreas.Epidemiological studies estimate a prevalence of 1 in 300 children in the United States with an increasing incidence of 2%-5%annually worldwide.The daily responsibility,clinical management,and vigilance required to maintain blood sugar levels within normal range and avoid acute complications(hypoglycemic episodes and diabetic ketoacidosis)and long term micro-and macro-vascular complications significantly affects quality of life and public health care costs.Given the expansive impact of T1D,research work has accelerated and T1D has been intensively investigated with the focus to better understand,manage and cure this condition.Many advances have been made in the past decades in this regard,but key questions remain as to why certain people develop T1D,but not others,with the glaring example of discordant disease incidence among monozygotic twins.In this review,we discuss the field’s current understanding of its pathophysiology and the role of genetics and environment on the development of T1D.We examine the potential implications of these findings with an emphasis on T1D inheritance patterns,twin studies,and disease prevention.Through a better understanding of this process,interventions can be developed to prevent or halt it at early stages.

Activin A receptor type 1C single nucleotide polymorphisms associated with esophageal squamous cell carcinoma risk in Chinese population

BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and metastasis.Activin A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis through binding to dif-ferent ligands.AIM To evaluate the correlation between single nucleotide polymorphisms(SNPs)of ACVR1C and susceptibility to esophageal squamous cell carcinoma(ESCC)in Chinese Han population.METHODS In this hospital-based cohort study,1043 ESCC patients and 1143 healthy controls were enrolled.Five SNPs(rs4664229,rs4556933,rs77886248,rs77263459,rs6734630)of ACVR1C were assessed by the ligation detection reaction method.Hardy-Weinberg equilibrium test,genetic model analysis,stratified analysis,linkage disequi-librium test,and haplotype analysis were conducted.RESULTS Participants carrying ACVR1C rs4556933 GA mutant had significantly decreased risk of ESCC,and those with rs77886248 TA mutant were related with higher risk,especially in older male smokers.In the haplotype analysis,ACVR1C Trs4664229Ars4556933Trs77886248Crs77263459Ars6734630 increased risk of ESCC,while Trs4664229Grs4556933Trs77886248Crs77263459Ars6734630 was associated with lower susceptibility to ESCC.CONCLUSION ACVR1C rs4556933 and rs77886248 SNPs were associated with the susceptibility to ESCC,which could provide a potential target for early diagnosis and treatment of ESCC in Chinese Han population.

Studies on Genetic Transformation of NPR1 Gene into Maize by Microprojectile Bombardment

[Objective] This study aimed to explore the conditions of transformation of maize by microprojectile bombardment. [Method] Immature embryo-derived callus of maize inbred line 7239 was used as explants to study the effects of shoot distance, helium pressure, vacuum and bombardment frequency on the transformation efficien- cy in the particle bombardment system of maize. [Result] Considering the transfor- mation efficiency, particle bombardment with 100 μg/P of golden particles, at a shoot distance of 9 cm from the target cells, under helium pressure of 1 350 psi and vac- uum 25 inHg, and bombarding twice could achieve relatively ideal results. After se- lection on media supplemented with different concentration of hygromycin, some re- generated plants were obtained. The results of PCR and Southern blotting analysis demonstrated that the NPR1 gene had been integrated into the genome of trans- genic maize plants, with an average transformation efficiency of 1.76%. [Conclusion] The study laid the foundation for the cultivation and breeding of excellent resistant varieties of maize.

Genetic Effects of ADAMTS-1 Gene on Reproductive Traits in Landrace Pig

The nucleotide sequences in exon 7 of a disintegrin and metalloproteinase with thrombospondin motifs-1(ADAMTS-1)gene in Landrace pig were obtained with cloning and sequencing by using PCR-RFLP technique in this experiment.Sequence alignment results showed that the C/G substitution in exon 7 induced amino acid change(Arg → Pro).AA,BB and AB genotypes were found in Landrace pig by PvuⅡ-RFLP.Correlation analysis between genotypes and reproductive traits indicated that ADAMTS-1 was significantly correlated with litter size(LS)and number born alive(NBA).

梨杂交F_(1)果实性状遗传倾向分析

以延边大香水为母本,红香酥、早酥、红茄、晋酥、晋密、鄂梨1号和云红1号为父本的7个梨杂交组合F_(1)为试材,对果实性状进行连续3年调查,总结分析果实性状遗传倾向,以期为梨遗传育种提供参考依据。结果表明:杂种F_(1)单果重、果实横径、果实纵径、果柄长度、果柄粗度、果形指数及可溶性固形物等7个性状都有趋中遗传倾向。其中,单果重产生退化,向小果遗传趋势强;可溶性固形物和果形指数变异系数较小,遗传传递力较高;果柄粗度呈趋中偏低遗传,果柄长度、果实横径、果实纵径呈趋中偏高遗传。对不同组合果实性状遗传倾向研究认为果实底色、萼片类型、萼洼深度、质地、汁液、风味等性状受母本影响较大,为母性遗传;萼洼广度有趋中遗传倾向;果实香气受父本影响较大;果实面色可隔代遗传。以上研究结果为梨果实性状遗传规律研究及杂交育种亲本的选择选配提供参考价值。

Construction and Genetic Transformation of Over-Expression Vector of nad1 Gene in Rice

[Objective] The aim was to clone the mitochondrial-related gene nad1 and produce transgenic rice plants with nad1.[Method] The total RNA was extracted from rice seedlings and reverse transcripted into cDNA.Then the target gene nad1 was amplified by using the cDNA as template.The nad1 and Rf1b,a sequence of signal peptide of mitochondria,were linked to binary expression vector pCAMBIA1305.1.The recombinant plasmid was transformed into the callus by Agrobacterium-mediated approach.[Result] The target gene nad1 was 978 bp.The binary expression vector carrying nad1 and signal peptide of mitochondria was constructed successfully.In addition,a lot of transgenic plants were obtained.[Conclusion] The study will provide basis to investigate the effect of over-expression of nad1 on rice plant growth.

X线修复交叉互补基因1多态性与进展期胃癌奥沙利铂联合卡培他滨方案化疗疗效的关系

目的:探讨X线修复交叉互补基因1(X-ray repair cross-complementing group 1,XRCC1) rs25487基因多态性与进展期胃癌奥沙利铂联合卡培他滨(XELOX方案)化疗的疗效及疾病进展时间的关系。方法:本研究为回顾性研究,入组110例进展期胃癌患者,均接受XELOX方案化疗,通过基质辅助激光解吸电离飞行时间质谱法的方法检测XRCC1 rs25487基因分型,分析患者临床病理特点及XRCC1 rs25487基因分型与患者化疗客观有效率(objective response rate, ORR)及疾病进展时间(progression-free survival, PFS)的关系。结果:110例进展期胃癌患者中,携带XRCC1 rs25487GG基因型、AG基因型、AA基因型分别为49例(44.5%)、52例(47.3%)、9例(8.2%),GG基因型患者ORR高于AG/AA基因型患者(53.1%vs 37.7%),但差异未达到统计学意义(χ^(2)=2.594,P=0.107)。GG基因型患者比AG/AA基因型患者PFS更长[6.3个月(95%CI:5.7~6.9)vs 5.0个月(95%CI:4.4~5.6),P=0.049]。患者临床病理特征均与化疗疗效无关,但肿瘤分化程度及TNM分期与PFS有关(P均<0.05)。Cox回归显示,肿瘤分化程度、TNM分期及XRCC1 rs25487是影响PFS的独立因素。结论:XRCC1 rs25487基因型与进展期胃癌患者XELOX方案化疗疗效密切相关,测定XRCC1 rs25487基因型可以为进展期胃癌的个体化治疗提供参考。

The relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans

AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret】0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls.

Genetic polymorphisms in glutathione S-transferase T1 affect the surgical outcome of varicocelectomies in infertile patients

Glutathione S-transferases （GSTs）, superoxide dismutase 2 （SOD2） and NAD（P）H：quinone oxidoreductase 1 （NQO1） are anti-oxidant enzyme genes. Polymorphisms of GSTs, SOD2 and NQO1 have been reported to influence individual susceptibility to various diseases. In an earlier study, we obtained preliminary findings that a subset of glutathione S-transferase 7：1 （GSTT1）-wt patients with varicocele may exhibit good response to varicocelectomy. In this study, we extended the earlier study to determine the distribution of genotype of each gene in the infertile population and to evaluate whether polymorphism of these genes affects the results of surgical treatment of varicocele. We analyzed 72 infertile varicocele patients, 202 infertile patients without varicocele and 101 male controls. Genotypes of GSTs were determined by polymerase chain reaction （PCR）. Genotyping of SOD2 and NQO1 was performed using the PCR-restriction fragment length polymorphism （PCR-RFLP） method. A significantly better response to varicocelectomy was found in patients with the GSTTI-wt genotype （63.2%） and NQO1-Ser/Ser genotype （80.0%） than in those with GSTTI-null genotype （35.3%） and NQO1-Pro/Pro or NQO1- Pro/Ser genotype （45.2%）, respectively. The frequencies of glutathione S-transferase M1/T1, SOD2 and NQO1 genotypes did not differ significantly among the varicocele patients, idiopathic infertile patients and male controls. GSTT1 genotype is associated with improvement of semen parameters after varicocelectomy. As the number of patients with NQO1-Ser/Ser genotype was not sufficient to reach definite conclusions, the association of NQO1 genotype with varicocelectomy requires further investigation.

Effects of dietary intake and genetic factors on hypermethyiation of the hMLH1 gene promoter in gastric cancer

AIM: Hypermethylation of the promoter of the hMLH1gene, which plays an important role in mismatch repair during DNA replication, occurs in more than 30% of human gastric cancer tissues. The purpose of this study was to investigate the effects of environmental factors, genetic polymorphisms of major metabolic enzymes, and microsatellite instability on hypermethylation of the promoter of the hMLH1 gene in gastric cancer.METHODS: Data were obtained from a hospital-based,case-control study of gastric cancer. One hundred and ten gastric cancer patients and 220 age- and sex-matched control patients completed a structured questionnaire regarding their exposure to environmental risk factors.Hypermethylation of the hMLH1 gene promoter,polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1,ALDH2 and L-myc genes, microsatellite instability and mutations of p53 and Ki-ras genes were investigated.RESULTS: Both smoking and alcohol consumption were associated with a higher risk of gastric cancer with hypermethylation of the hMLH1 gene promoter. High intake of vegetables and low intake of potato were associated with increased likelihood of gastric cancer with hypermethylation of the hMLH1 gene promoter. Genetic polymorphisms of the GSTM1, GSTT1, CYP1A1, CYP2E1,ALDH2, and L-mycgenes were not significantly associated with the risk of gastric cancer either with or without hypermethylation in the promoter of the hMLH1 gene.Hypermethylation of the hMLH1 promoter was significantly associated with microsatellite instability (MSI): 10 of the 14 (71.4%) MSI-positive tumors showed hypermethylation,whereas 28 of 94 (29.8%) the MSI-negative tumors were hypermethylated at the hMLH1 promoter region.Hypermethylation of the hMLH1 gene promoter was significantly inversely correlated with mutation of the p53gene.CONCLUSION: These results suggest that cigarette smoking and alcohol consumption may influence the development of hMLH1-positive gastric cancer. Most dietary factors and polymorphisms of GSTM1, GSTT1,CYP1A1, CYP2E1, ALDH2, and L-myc genes are not independent risk factors for gastric cancer with hypermethylation of the hMLH1 promoter. These data also suggest that there could be two or more different molecular pathways in the development of gastric cancer, perhaps involving tumor suppression mechanisms or DNA mismatch repair.

Pharmacogenetics of the systemic treatment in advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) accounts for the majority of primary liver cancers. To date, most patients with HCC are diagnosed at an advanced tumor stage, excluding them from potentially curative therapies (i.e., resection, liver transplantation, percutaneous ablation). Treatments with palliative intent include chemoembolization and systemic therapy. Among systemic treatments, the small-molecule multikinase inhibitor sorafenib has been the only systemic treatment available for advanced HCC over 10 years. More recently, other smallmolecule multikinase inhibitors (e.g., regorafenib, lenvatinib, cabozantinib) have been approved for HCC treatment. The promising immune checkpoint inhibitors (e.g., nivolumab, pembrolizumab) are still under investigation in Europe while in the US nivolumab has already been approved by FDA in sorafenib refractory or resistant patients. Other molecules, such as the selective CDK4/6inhibitors (e.g., palbociclib, ribociclib), are in earlier stages of clinical development, and the c- MET inhibitor tivantinib did not show positive results in a phase III study. However, even if the introduction of targeted agents has led to great advances in patient response and survival with an acceptable toxicity profile, a remarkable inter-individual heterogeneity in therapy outcome persists and constitutes a significant problem in disease management. Thus, the identification of biomarkers that predict which patients will benefit from a specific intervention could significantly affect decision-making and therapy planning. Germ-line variants have been suggested to play an important role in determining outcomes of HCC systemic therapy in terms of both toxicity and treatment efficacy. Particularly, a number of studies have focused on the role of genetic polymorphisms impacting the drug metabolic pathway and membrane translocation as well as the drug mechanism of action as predictive/prognostic markers of HCC treatment. The aim of this review is to summarize and critically discuss the pharmacogenetic literature evidences, with particular attention to sorafenib and regorafenib, which have been used longer than the others in HCC treatment.

Genetic polymorphisms in cytochrome P4502E1, alcohol and aldehyde dehydrogenases and the risk of esophageal squamous cell carcinoma in Gansu Chinese males

AIM:To evaluate the association between genetic polymorphisms in CYP2E1, ALDH2 and ADH1B and the risk of esophageal squamous cell carcinoma (ESCC) in a high risk area of Gansu Province, in Chinese males. METHODS: A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYP2E1 *c1/*c2, ALDH2 *1/*2 and ADH1B *1/*1 genotypes). A total of 80 esophageal cancer cases and 480 controls were recruited. RESULTS: Compared with controls, cases had a greater prevalence of heavier alcohol consumption (53.8% vs 16.2%) and a higher proportion of alcohol drinkers with > 30 drink-years (28.8% vs 13.5%). Heavier alcohol consumption and alcohol drinking with > 30 drink- years increased the risk of ESCC, with ORs (95% CI) of 3.20 (1.32-9.65) and 1.68 (0.96-3.21). CYP2E1 (*c1/*c1), ALDH2 (*1/*2) and ADH1B (*1/*1) genotype frequencies were higher among patients with squamous cell carcinomas, at a level close to statistical significance (P = 0.014; P = 0.094; P = 0.0001 respectively). There were synergistic interactions among alcohol drinking and ALDH2, ADH1B and CYP2E1 genotypes. The risk of the ESCC in moderate-to-heavy drinkers with an inactive ALDH2 encoded by ALDH2 *1/*2 as well as ADH1B encoded by ADH1B *1/*1 and CYP2E1 encoded by CYP2E1 *c1/*c1 was higher than that in the never/rare-to-light drinkers with an active ALDH2 (*1/*1 genotype) as well as ADH1B (*1/*2 + *2/*2) and CYP2E1 (*c1/*c2 + *c2/*c2) genotypes, with a statistically significant difference; ORs (95% CI) of 8.58 (3.28-22.68), 27.12 (8.52-70.19) and 7.64 (2.82-11.31) respectively. The risk of the ESCC in moderate-to-heavy drinkers with ALDH2 (*1/*2) combined the ADH1B (*1/*1) genotype or ALDH2 (*1/*2) combined the CYP2E1 (*c1/*c1) genotype leads to synergistic interactions, higher than drinkers with ALDH2 (*1/*1) + ADH1B (*1/*2 + *2/*2), ALDH2 (*1/*1) + CYP2E1 (*c1/*c2 + *c2/*c2) respectively , ORs (95% CI) of 7.46 (3.28-18.32) and 6.82 (1.44-9.76) respectively. Individuals with the ADH1B combined the CYP2E1 genotype showed no synergistic interaction. CONCLUSION: In our study, we found that alcohol consumption and polymorphisms in the CYP2E1, ADH1B and ALDH2 genes are important risk factors for ESCC, and that there was a synergistic interaction among polymorphisms in the CYP2E1, ALDH2 and ADH1B genes and heavy alcohol drinking, in Chinese males living in Gansu Province, China.

LZTR1基因Arg284His变异致Noonan综合征10型病例报道和遗传学分析

目的 对1例Noonan综合征10型(NS10)患儿进行临床特征和遗传学分析。方法 对患儿及其父母进行家系全外显子组(trio-WES)检测,采用生物信息学方法对基因变异进行危害性分析,预测变异蛋白结构功能,采用免疫印迹法检测变异蛋白的表达量。结果 患儿年龄为8岁9个月,临床表现为生长发育迟缓、先天性心脏病和特殊面容等。基因检测结果提示患儿亮氨酸拉链样转录调控因子1(LZTR1)基因发生杂合变异c.851G>A(p.Arg284His)(NM_6767.4),其父亲携带该变异,母亲为野生型。Pubmed数据库和HGMD数据库未检索到相应变异的报道,属LZTR1基因新变异。SIFT、Polyphen-2和MutationTaster在线软件分析结果显示到LZTR1 c.851G>A(p.Arg 284His)变异存在生物危害性。蛋白结构模型分析结果显示,LZTR1 c.851G>A(p.Arg 284His)变异可导致LZTR1蛋白局部结构改变。免疫印迹法结果显示,与野生型LZTR1蛋白比较,变异型LZTR1蛋白的表达量降低了81.20%。结论 LZTR1基因c.851G>A(p.Arg 284His)变异可能是NS10的致病原因。

Cytochrome P450 2E1 genetic polymorphism and gastric cancer in Changle,Fujian Province

AIM: Genetic polymorphism in enzymes of carcinogen metabolism has been found to have the influence on the susceptibility to cancer. Cytochrome P450 2E1 (CYP2E1) is considered to play an important role in the metabolic activation of procarcinogens such as N-nitrosoamines and low molecular weight organic compounds. The purpose of this study is to determine whether CYP450 2E1 polymorphisms are associated with risks of gastric cancer. METHODS: We conducted a population based case-control study in Changle county, Fujian Province, a high-risk region of gastric cancer in China. Ninety-one incident gastric cancer patients and ninety-four healthy controls were included in our study. Datas including demographic characteristics, diet intake, and alcohol and tobacco consumption of individuals in our study were completed by a standardized questionnaire.PCR-RFLP revealed three genotypes:heterozygote (C1/C2) and two homozygotes (C1/C1 and C2/C2) in CYP2E1. RESULTS: The frequency of variant genotypes (C1/C2 and C2/C2) in gastric cancer cases and controls was 36.3% and 24.5%, respectively. The rare homozygous C2/C2 genotype was found in 6 individuals in gastric cancer group(6.6%), whereas there was only one in the control group (1.1%). However, there was no statistically significant difference between the two groups (two-tailed Fisher's exact test P=0.066). Individuals in gastric cancer group were more likely to carry genotype C1/C2 (odds ratio, OR=1.50) and C2/C2 (OR=7.34) than individuals in control group (chi(2) =4.597, for trend P=0.032). The frequencies of genotypes with the C2 allele (C1/C2 and C2/C2 genotypes) were compared with those of genotypes without C2 allele (C1/C1 genotype) among individuals in gastric cancer group and control group according to the pattern of gastric cancer risk factors. The results show that individuals who exposed to these gastric cancer risk factors and carry the C2 allele seemed to have a higher risk of developing gastric cancer. CONCLUSION: Polymorphism of CYP2E1 gene may have some effect in the development of gastric cancer in Changle county, Fujian Province.

No association between cyclooxygenase-2 and uridine diphosphate glucuronosyltransferase 1A6 genetic polymorphisms and colon cancer risk

AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with risk of colon cancer.METHODS： NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly,enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGTIA6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms （SNPs） in the COX2 and UGTIA6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls.RESULTS： No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk （P 〉 0.05）,and we did not observe that these variants modify the protective effect of NSAIDs （P 〉 0.05）. We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas.CONCLUSION： Our study does not support a role of COX2 and UGTIA6 genetic variations in the development of colon cancer.

Genetic polymorphism of glutathione S-transferase T1 gene and susceptibility to idiopathic azoospermia or oligospermia in northwestern China

Aim： To investigate the association of glutathione S-transferase T1 （GSTT1） gene polymorphism in patients with idiopathic azoospermia or oligospermia in the northwestern China population. Methods： In the case-control study, GSTT1 genotypes were identified by multiplex polymerase chain reaction （PCR） with peripheral blood DNA samples from 78 patients with idiopathic azoospermia, 103 patients with idiopathic oligospermia and 156 age-matched controls with normal sperm concentration and motility, according to the criteria adapted from World Health Organization guidelines. All of the patients and controls were from northwestern China. Results： There is a significant association between GSTT1 null genotype with idiopathic azoospermia risk （odds ratio [OR]： 2.36, 95% confidence interval [CI]： 1.33-4.20, P = 0.003） or idiopathic oligospermia risk （OR： 2.00, 95% CI： 1.17-3.27, P = 0.010）. Conclusion： GSTT1 null genotype is a predisposing risk factor for sporadic idiopathic azoospermia or oligospermia in northwestern China. （Asian J Androl 2008 Mar; 10： 266-270）

HLA-DQB1~* alleles and genetic susceptibility to type 1 diabetes mellitus

AIM: To determine human leukocyte antigen (HLA)-DQB1 allele association with susceptibility to type 1 diabetes (T1D) and to clinical and laboratory findings. METHODS: This study was conducted on 85 unrelated Egyptian children with T1D recruited consecutively from the Pediatric Diabetes Endocrinology outpatients Clinic; Mansoura University Children’s Hospital, Egypt. Patient mean follow up period was 2.5 years. Patients were subdivided according to level of HbA1c (optimal/suboptimal control < 8.5% and poor control ≥ 8.5%). The control group consisted of 113 unrelated age- and sex-matched healthy subjects without T1D or other autoimmune diseases. Genomic DNA extraction was done for all subjects using a DNA isolation kit. HLA-Class II-DQB1 allele typing was carried out with a polymerase chain reaction-sequence-specific oligonucleotide probe using a INNO-LiPA HLA-DQB1 update kit. RESULTS: Significant differences were detected between Egyptian patients with T1D and control groups in the frequencies of DQB1*02 [44.4% vs 18.6%, corrected P value (Pc) < 0.001] and DQB1*03 (41.2% vs 24.4%, Pc < 0.001). Significant differences were also observed between control groups and T1D patients in the frequencies of DQB1*05 (14.6% vs 7.2%, P = 0.029) and DQB1*06 (34.1% vs 7.2%, P < 0.001). However, after correction for multiple comparisons, the significance was retained for HLA-DQB1*06 (Pc < 0.001) but lost for HLA-DQB1*05. HLA-DQB1*0201, *0202, *030201 were positively associated with T1D (Pc = 0.014, Pc < 0.001, and Pc < 0.001 respectively), while HLA-DQB1*060101 was negatively associated (Pc < 0.001) with the condition. Although the HLA-DQB1 alleles 030101 and 050101 were significantly higher in controls (P = 0.016, P = 0.025 respectively), both of them lost statistical significance after correction of P value. The frequency of the HLA-DQB1 genotypes 02/02, 02/03, and 03/03 was higher in T1D patients, and the frequency of the genotypes 03/06, 05/06, and 06/06 was higher in controls, these differences being statistically significant before correction. After correction, the genotypes 02/02, 02/03 in T1D, and the genotypes 03/06, 06/06 in controls were still significant (Pc = 0.01, Pc < 0.001, Pc < 0.001, and Pc = 0.04, respectively). Non-significant associations were found between the frequency HLA-DQB1 alleles and genotypes in T1D in relation to the grade of diabetic control, Microalbuminuria, age, gender, age of presentation, weight, height, frequency of diabetic ketoacidosis (P = 0.42), serum cholesterol, and fasting and post-prandial level of C-peptide (P = 0.83, P = 0.9, respectively). CONCLUSION: The Current work suggests that HLA-DQB1 alleles *030201, *0202, *0201, and genotypes 02/03, 02/02 may be susceptibility risk factors for development of T1D in Egyptian children, while the HLA-DQB1*060101 allele, and 03/06, 06/06 genotypes may be protective factors. HLA-DQB1 alleles and genotypes do not contribute to microalbuminuria or grade of diabetic control.

Recent advances in the molecular genetics of type 2 diabetes mellitus

Type 2 diabetes mellitus(T2DM) is a complex disease in which both genetic and environmental factors interact in determining impaired β-cell insulin secretion and peripheral insulin resistance. Insulin resistance in muscle, liver and fat is a prominent feature of most patients with T2DM and obesity, resulting in a reduced response of these tissues to insulin. Considerable evidence has been accumulated to indicate that heredity is a major determinant of insulin resistance and T2DM. It is believed that, among individuals destined to develop T2DM, hyperinsulinemia is the mechanism by which the pancreatic β-cell initially compensates for deteriorating peripheral insulin sensitivity, thus ensuring normal glucose tolerance. Most of these people will develop T2DM when β-cells fail to compensate. Despite the progress achieved in this field in recent years, the genetic causes of insulin resistance and T2DM remain elusive.Candidate gene association, linkage and genome-wide association studies have highlighted the role of genetic factors in the development of T2DM. Using these strategies, a large number of variants have been identified in many of these genes, most of which may influence both hepatic and peripheral insulin resistance, adipogenesis and β-cell mass and function. Recently, a new gene has been identified by our research group, the HMGA1 gene, whose loss of function can greatly raise the risk of developing T2DM in humans and mice. Functional genetic variants of the HMGA1 gene have been associated with insulin resistance syndromes among white Europeans, Chinese individuals and Americans of Hispanic ancestry. These findings may represent new ways to improve or even prevent T2DM.

Genetic test in multiple endocrine neoplasia type 1 syndrome: An evolving story

Multiple endocrine neoplasia type 1(MEN1) is an autosomal dominant inherited tumour syndrome expressing various endocrine and non-endocrine lesions and tumours. Since the identification of the causative gene, the oncosuppressor gene MEN1, in 1997, genetic testing has revealed an important approach for the early and differential diagnosis of the disease. The finding of a MEN1 mutation in a patient has important clinical implications for relatives since it allows very early disease diagnosis and identification of carriers, even before biochemical and/or clinical manifestation, permitting their inclusion in a specific program of surveillance and subsequent praecox therapy. Currently, genetic testing for MEN1 consists principally of the sequencing of coding regions and intron-exon junctions of the MEN1 gene. However, the recent acquisition of novel high throughput technologies will allow the design of innovative, accurate, complete and rapid genetic diagnosis. These new tools are able to increase the strength of the analysis and almost completely eliminate the possibility of false negative results. This review aims to give an overview on genetic testing of MEN1 syndrome, reporting the positive aspects of performing the analysis and the future perspectives for improving the performance of the test, as well as its application in clinical practice.

Genetic Analysis of the P1 Region of Human Enterovirus 71 Strains and Expression of the 55 F StrainVP1 Protein

Enterovirus 71 （EV71） is a member of the Entero-virus genus of the Picomaviridae family and is the major cause of Hand, foot, and mouth disease （HFMD） in children. Different strains from Gansu were cloned and the P1 protein was sequenced and analysed. Results indicate that there are three kinds of EV71 infections prevalent in Gansu. The VP 1 protein from one of these strains, 55F, was expressed. The recombinant protein was expressed with high level and reacted specifically with the EV71 patient antibody, the recombinant protein was also applied to raise antiserum in rabbits and after the fourth injection a high titer of antiserum was detected by ELISA assay. These data are useful for further clarification of prevalent EV71 strains in the north of China at the molecular level and provide a basis for EV71 diagnosis.