Association between polymorphism of NUDT15 gene and hepatotoxicity induced by 6-MP in children with acute lymphoblastic leukemia / 中华医学遗传学杂志

OBJECTIVE@#To investigate the association between single nucleotide polymorphism of NUDT15 gene (SNP rs116855232) and hepatotoxicity in children with acute lymphocytic leukemia (ALL).@*METHODS@#A total of 135 children with ALL in Shandong Province were recruited in this study, and patients were divided into two groups based on the presence of liver injury. Genotypes of each patient were detected using PCR and Sanger sequencing. Clinical data and the average dose of 6-mercaptopurine (6-MP) were collected and analyzed by SPSS 19.0 software.@*RESULTS@#Respectively, 99 patients were found with CC genotype, 32 patients with CT genotype and 4 patients with TT genotype. Compared with ALL patients without hepatotoxicity, there was a difference in genotypes between the two groups in the initial stage of chemotherapy for leukemia (Chi@*CONCLUSION@#The polymorphism of rs116855232 in NUDT15 gene was associated with hepatotoxicity induced by 6-mercaptopurine in children with ALL, and ALL patients with TT genotype should take a lower dose of 6-MP to avoided hepatotoxicity.

The heterologous expression of Escherichia coli MutT enzyme is involved in the protection against oxidative stress in Leishmania braziliensis

BACKGROUND Oxidative stress is responsible for generating DNA lesions and the 8-oxoguanine (8-oxoG) is the most commonly lesion found in DNA damage. When this base is incorporated during DNA replication, it could generate double-strand DNA breaks and cellular death. MutT enzyme hydrolyzes the 8-oxoG from the nucleotide pool, preventing its incorporation during DNA replication. OBJECTIVES To investigate the importance of 8-oxoG in Leishmania infantum and L. braziliensis, in this study we analysed the impact of heterologous expression of Escherichia coli MutT (EcMutT) enzyme in drug-resistance phenotype and defense against oxidative stress. METHODS Comparative analysis of L. braziliensis and L. infantum H2O2 tolerance and cell cycle profile were performed. Lines of L. braziliensis and L. infantum expressing EcMutT were generated and evaluated using susceptibility tests to H2O2 and SbIII, cell cycle analysis, γH2A western blotting, and BrdU native detection assay. FINDINGS Comparative analysis of tolerance to oxidative stress generated by H2O2 showed that L. infantum is more tolerant to exogenous H2O2 than L. braziliensis. In addition, cell cycle analysis showed that L. infantum, after treatment with H2O2, remains in G1 phase, returning to its normal growth rate after 72 h. In contrast, after treatment with H2O2, L. braziliensis parasites continue to move to the next stages of the cell cycle. Expression of the E. coli MutT gene in L. braziliensis and L. infantum does not interfere in parasite growth or in susceptibility to SbIII. Interestingly, we observed that L. braziliensis EcMutT-expressing clones were more tolerant to H2O2 treatment, presented lower activation of γH2A, a biomarker of genotoxic stress, and lower replication stress than its parental non-transfected parasites. In contrast, the EcMutT is not involved in protection against oxidative stress generated by H2O2 in L. infantum. MAIN CONCLUSIONS Our results showed that 8-oxoG clearance in L. braziliensis is important to avoid misincorporation during DNA replication after oxidative stress generated by H2O2.

The hepatic ectonucleotide pyrophosphatase/phosphodiesterase 1 gene mRNA abundance is reduced by insulin and induced by dexamethasone

Hormones regulate hepatic gene expressions to maintain metabolic homeostasis. Ectonucleotide pyrophosphatase/phosphodiesterase 1 has been thought to interfere with insulin signaling. To determine its potential role in the regulation of metabolism, we analyzed its gene (Enpp1) expression in the liver of rats experiencing fasting and refeeding cycles, and in primary rat hepatocytes and human hepatoma HepG2 cells treated with insulin and dexamethasone using northern blot and real-time PCR techniques. Hepatic Enpp1 expression was induced by fasting and reduced by refeeding in the rat liver. In primary rat hepatocytes and HepG2 hepatoma cells, insulin reduced Enpp1 mRNA abundance, whereas dexamethasone induced it. Dexamethasone disrupted the insulin-reduced Enpp1 expression in primary hepatocytes. This is in contrast to the responses of the expression of the cytosolic form of phosphoenolpyruvate carboxykinase gene to the same hormones, where insulin reduced it significantly in the process. In addition, the dexamethasone-induced Enpp1 gene expression was attenuated in the presence of 8-Br-cAMP. In conclusion, we demonstrated for the first time that hepatic Enpp1 is regulated in the cycle of fasting and refeeding, a process that might be attributed to insulin-reduced Enpp1 expression. This insulin-reduced Enpp1 expression might play a role in the development of complications in diabetic patients.

High Prevalence of ITPA Alleles Associated with Ribavirin-Induced Hemolytic Anemia Among Mexican Population

ABSTRACT Background. The prevalence of two functional polymorphisms (rs1127354 and rs7270101) of the inosine triphosphatase (ITPA) gene associated with ribavirin-induced hemolytic anemia (RIHA) during antiviral therapy for hepatitis C virus (HCV) infection varies by ethnicity. In Mexico, the distribution of these polymorphisms among Native Amerindians (NA) and admixed population (Mestizos) is unknown. This study aimed to determine the prevalence of the ITPA polymorphisms among healthy NA and Mestizos, as well as in HCV patients from West Mexico. Material and methods. In a cross-sectional study, 600 unrelated subjects (322 Mestizos, 100 NA, and 178 treatment-naïve, HCV-infected Mestizos patients) were enrolled. A medical history was registered. ITPA genotype was determined by Real-Time PCR. Fst-values and genetic relatedness between study and reference populations were assessed. Results. The frequency of the risk genotypes rs1127354CC and rs7270101AA was higher among NA (98-100%) than in Mestizos (87-92.9%), (p < 0.05). The NA presented the highest prevalence of the rs1127354CC genotype reported worldwide. The Fst-values revealed a genetic relatedness among Mexican NA, South Americans and African populations (p > 0.05). The frequency of the predicted risk for RIHA was higher among NA (98%) than in Mestizos (80.5%) and HCV-infected patients (81.5%) (p < 0 .01). The CC/AA alleles were associated with lower values of total bilirubin, aspartate/alanine aminotransferases, and aspartate-to-platelet-ratio-index score among HCV-patients. Conclusion. A high prevalence of the ITPA polymorphisms associated with RIHA was found in Mexican NA. These polymorphisms could be a useful tool for evaluating potential adverse effects and the risk or benefit of antiviral therapy in Mexicans and other admixed populations.

Inosine triphosphatase allele frequency and association with ribavirin-induced anaemia in Brazilian patients receiving antiviral therapy for chronic hepatitis C

Inosine triphosphatase (ITPA) single nucleotide polymorphisms (SNPs) are strongly associated with protection against ribavirin (RBV)-induced anaemia in European, American and Asian patients; however, there is a paucity of data for Brazilian patients. The aim of this study was to evaluate the ITPA SNP (rs7270101/rs1127354) frequency in healthy and hepatitis C virus (HCV)-infected patients from Brazil and the association with the development of severe anaemia during antiviral therapy. ITPA SNPs were determined in 200 HCV infected patients and 100 healthy individuals by sequencing. Biochemical parameters and haemoglobin (Hb) levels were analysed in 97 patients who underwent antiviral therapy. A combination of AArs7270101+CCrs1127354 (100% ITPase activity) was observed in 236/300 individuals. Anaemia was observed in 87.5% and 86.2% of treated patients with AA (rs7270101) and CC genotypes (rs1127354), respectively. Men with AA (rs7270101) showed a considerable reduction in Hb at week 12 compared to those with AC/CC (p = 0.1475). In women, there was no influence of genotype (p = 0.5295). For rs1127354, men with the CC genotype also showed a sudden reduction in Hb compared to those with AC. Allelic distribution of rs7270101 and rs1127354 shows high rates of the genotypes AA and CC, respectively, suggesting that the study population had a great propensity for developing RBV-induced anaemia. A progressive Hb reduction during treatment was observed; however, this reduction was greater in men at week 12 than in women.

Association between IPTA Gene Polymorphisms and Hematological Abnormalities in Hepatitis C Virus-Infected Patients Receiving Combination Therapy

BACKGROUND/AIMS: Hematological abnormalities during hepatitis C virus (HCV) combination therapy with pegylated interferon alpha and ribavirin often necessitate dose reduction. Variants of the ITPA gene have been reported to protect against anemia during the early stages of HCV combination treatments but have also been associated with larger decreases in platelet counts. We aimed to identify the association between specific ITPA gene polymorphisms and hematological abnormalities in patients undergoing HCV combination therapy. METHODS: In this retrospective study, 175 patients treated with HCV combination therapy were enrolled at St. Martin De Porres Hospital in Taiwan between 2006 and 2012. Two single nucleotide polymorphisms (SNP) within or adjacent to the ITPA gene (rs1127354, rs6051702) were genotyped. We investigated the effect of ITPA gene variants on hematological abnormalities during the therapy. RESULTS: The ITPA rs1127354 minor variants were significantly associated with protection against anemia at week 4 (p=1.86 x 10(-6)) and with more severe decreases in platelet counts during HCV combination therapy. SNP rs6051702 was not associated with the hemoglobin decline to >3 g/dL at week 4 in our study (p=0.055). CONCLUSIONS: The ITPA SNP rs1127354 is a useful predictor of ribavirin-induced anemia in Taiwanese patients and may be related to more severe decreases in platelet counts during the early stage of HCV combination therapy.

Association between IPTA Gene Polymorphisms and Hematological Abnormalities in Hepatitis C Virus-Infected Patients Receiving Combination Therapy

BACKGROUND/AIMS: Hematological abnormalities during hepatitis C virus (HCV) combination therapy with pegylated interferon alpha and ribavirin often necessitate dose reduction. Variants of the ITPA gene have been reported to protect against anemia during the early stages of HCV combination treatments but have also been associated with larger decreases in platelet counts. We aimed to identify the association between specific ITPA gene polymorphisms and hematological abnormalities in patients undergoing HCV combination therapy. METHODS: In this retrospective study, 175 patients treated with HCV combination therapy were enrolled at St. Martin De Porres Hospital in Taiwan between 2006 and 2012. Two single nucleotide polymorphisms (SNP) within or adjacent to the ITPA gene (rs1127354, rs6051702) were genotyped. We investigated the effect of ITPA gene variants on hematological abnormalities during the therapy. RESULTS: The ITPA rs1127354 minor variants were significantly associated with protection against anemia at week 4 (p=1.86 x 10(-6)) and with more severe decreases in platelet counts during HCV combination therapy. SNP rs6051702 was not associated with the hemoglobin decline to >3 g/dL at week 4 in our study (p=0.055). CONCLUSIONS: The ITPA SNP rs1127354 is a useful predictor of ribavirin-induced anemia in Taiwanese patients and may be related to more severe decreases in platelet counts during the early stage of HCV combination therapy.

Impact of ENPP1 K121Q on Change of Insulin Resistance after Web-Based Intervention in Korean Men with Diabetes and Impaired Fasting Glucose

Ectoenzyme nucleotide pyrophosphate phosphodiesterase 1 (ENPP1) gene has been studied in relation to type 2 diabetes mellitus (T2DM) and insulin resistance (IR). We hypothesized that the difference in genotype may be one of the factors that affect the outcome of intervention. We genotyped 448 men with fasting glucose> or =5.6 mM/L, including 371 in subjects with K allele (KK) (69 control group [CG]; and 302 intervention group [IG]) and 77 in subjects with Q allele (KQ+QQ) (13 CG and 64 IG). The web-based intervention based on a lifestyle modification was delivered by e-mail once a month for 10 months. In the KK, IG demonstrated significantly decreased levels of fasting serum insulin (FSI) as compared to CG and homeostasis model of assessment of insulin resistance (HOMA-IR). In the KQ+QQ IG group, hemoglobin A1c (HbA1c), FSI and HOMA-IR were significantly decreased, and showed further reduction in the HOMA-IR than KQ+QQ CG. After analysis of covariance, K121Q did significantly influence the change of HbA1c in CG after appropriate adjustment. In a multivariate model, BMI change predicted HOMA-IR change (adjusted beta=0.801; P=0.022) in KK IG subjects with T2DM. ENPP1 K121Q did not influence the change in IR. However, individuals with T2DM carrying the K121 variant are very responsive to the effect of BMI reduction on HOMA-IR.

The Impact of Inosine Triphosphatase Variants on Hemoglobin Level and Sustained Virologic Response of Chronic Hepatitis C in Korean

Two variants of the inosine triphosphatase (ITPA: rs1127354, rs7270101) gene cause ITPA deficiency and protect against the hemolytic toxicity of ribavirin. We investigated the clinical significance of ITPA variants in Korean patients treated with pegylated interferon (PEG-IFN) plus ribavirin. Of the 133 patients, 108 were CC and 25 were non-CC at rs1127354 (groups A and B, respectively). On the other hand, at rs7270101 all 133 were AA. The mean values of Hemoglobin (Hgb) after 4, 8, and 12 weeks of treatment in groups A and B were 12.2 and 14.0, 11.8 and 13.2, and 11.5 and 12.9, respectively (P=0.001, 0.036, 0.036). Sustained virologic response (SVR) was achieved in 67.8% (40/59) of genotype 1 patients and in 75% (27/36) of non-genotype 1 patients. Regarding ITPA variants, SVR was achieved by 66% and 80% of genotype 1 (P=0.282), and by 78% and 71% (P=0.726) of non-genotype 1. SVR was not significantly different in groups A and B. In conclusion, non-CC at rs1127354 without involvement of rs7270101 is strongly associated with protection from ribavirin-induced anemia, however, ITPA genotype is not associated with SVR.

The role of ecto-nucleotide pyrophosphatase/phosphodiesterase 1 in diabetic nephropathy / Papel da ectonucleotídeo pirofosfatase/fosfodiesterase 1 (ENPP1) na nefropatia diabética

The increased prevalence of diabetes mellitus has caused a rise in the occurrence of its chronic complications, such as diabetic nephropathy (DN), which is associated with elevated morbidity and mortality. Familial aggregation studies have demonstrated that besides the known environmental risk factors, DN has a major genetic component. Therefore, it is necessary to identify genes associated with risk for or protection against DN. Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is expressed in several tissues, including the kidneys. Increased levels of ENPP1 expression inhibit tyrosine-kinase activity of the insulin receptor in several cell types, leading to insulin resistance. K121Q polymorphism of the ENPP1 gene seems to be associated with insulin resistance and DN development. The elucidation of genetic factors and their associations will provide better understanding of the pathogenesis of DN and, may consequently, lead to a more effective approach to prevention and treatment.

A crescente prevalência do diabetes melito tem causado aumento na ocorrência das suas complicações crônicas, como a nefropatia diabética (ND), a qual está associada com elevada morbidade e mortalidade. Estudos de agregação familiar demonstram que a ND tem um importante componente genético, além dos conhecidos fatores de risco ambientais. Portanto, existe a necessidade de se identificarem genes associados ao risco ou proteção à ND. A ectonucleotide pyrophosphatase/phosphodiesterase 1(ENPP1) é expressa em vários tecidos, incluindo nos rins. Foi encontrado que níveis aumentados de expressão da ENPP1 inibem a atividade tirosino-quinase do receptor da insulina em vários tipos celulares, causando resistência à insulina. O polimorfismo K121Q do gene ENNP1parece estar associado com resistência à insulina e com o desenvolvimento da ND. A elucidação dos fatores genéticos e de suas associações permitirá um melhor entendimento da patogênese da ND e, consequentemente, poderemos ter uma abordagem mais efetiva em sua prevenção e tratamento.

Polimorfismo K121Q do gene ENPP1 e cardiopatia isquêmica em pacientes com diabete melito / Polimorfismo K121Q del gen ENPP1 y cardiopatía isquémica en pacientes con diabetes melitus / ENPP1 K121Q polymorphism and ischemic heart disease in diabetic patients

FUNDAMENTO: O gene ecto-nucleotídeo pirofosfatase/fosfodiesterase 1 (ENPP1) é um gene candidato à resistência insulínica. A resistência à insulina é um componente importante da síndrome metabólica e tem sido implicada no desenvolvimento de doença cardíaca isquêmica (DCI). OBJETIVO: Avaliar a associação entre o polimorfismo K121Q do gene ENPP1 e a presença da DCI em pacientes caucasianos com diabete melito (DM) tipo 2. MÉTODOS: Estudo transversal foi realizado em pacientes com DM tipo 2 (n=573; 50,6 por cento homens; idade 59,5±10,4 anos). DCI foi definida pela presença de angina ou infarto agudo do miocárdio pelo questionário cardiovascular da Organização Mundial da Saúde e/ou alterações compatíveis no ECG (código Minnesota) ou cintilografia miocárdica. O polimorfismo K121Q foi genotipado através da técnica de PCR e digestão enzimática. RESULTADOS: DCI esteve presente em 209 (36,5 por cento) pacientes. A frequência dos genótipos KK, KQ e QQ entre os pacientes com DCI foi 60,8 por cento, 34,4 por cento e 4,8 por cento, semelhante à distribuição dos genótipos entre os pacientes sem DCI (64,0 por cento, 32,7 por cento e 3,3 por cento, P = 0,574). Não se observou diferença nas características clínicas ou laboratoriais entre os três genótipos, nem em relação à presença de síndrome metabólica. CONCLUSÃO: Nenhuma associação foi encontrada entre o polimorfismo K121A do gene ENPP1 e a presença de DCI ou características fenotípicas de resistência insulínica.

BACKGROUND: The ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene is a candidate gene for insulin resistance. Insulin resistance is a major component of metabolic syndrome (MetS) and has been implicated in ischemic heart disease (IHD). OBJECTIVE: To evaluate the association between the K121Q polymorphism of the ENPP1 gene and IHD in white patients with type 2 diabetes mellitus (DM). METHODS: A cross-sectional study was performed in type 2 DM patients (n = 573, 50.6 percent males, age 59.5±10.4 years). IHD was defined by the presence of angina or myocardial infarction according to the Worth Health Organization cardiovascular questionnaire and/or compatible electrocardiographic (Minnesota Code), or perfusional abnormalities in myocardial scintigraphy. The K121Q polymorphism of ENPP1 gene was genotyped using PCR-based methods and restriction enzyme digestion. RESULTS: IHD was present in 209 (36.5 percent) patients. The distribution of KK, KQ and QQ genotypes among patients with IHD was 60.8 percent, 34.4 percent and 4.8 percent, not different from the genotype distribution in the group without IHD (64 percent, 32.7 percent and 3.3 percent, P=0.574). No difference was found in the clinical and laboratory characteristics between the three genotypes, neither regarding the prevalence of Metabolic Syndrome. CONCLUSION: No association was found between polymorphism K121A of ENPP1 gene and the presence of IHD.

FUNDAMENTO: El gen ecto-nucleótido pirofosfatasa/fosfodiesterasa 1 (ENPP1) es un gen candidato a la resistencia insulínica. La resistencia a la insulina es un componente importante del síndrome metabólico y ha sido involucrada en el desarrollo de enfermedad cardiaca isquémica (ECI). OBJETIVO: Evaluar la asociación entre el polimorfismo K121Q del gen ENPP1 y la presencia de ECI en pacientes caucásicos con diabetes melitus (DM) tipo 2. MÉTODOS: SE Realizó un estudio transversal en pacientes con DM tipo 2 (n=573; 50,6 por ciento hombres; edad 59,5±10,4 años). Se definió la ECI por la presencia de angina o infarto agudo de miocardio mediante el cuestionario cardiovascular de la Organización Mundial de la Salud y/o alteraciones compatibles en el ECG (código Minnesota) o centellograma miocárdico. El polimorfismo K121Q fue genotipificado mediante la técnica de PCR y digestión enzimática. RESULTADOS: La ECI estuvo presente en 209 (36,5 por ciento) pacientes. La frecuencia de los genotipos KK, KQ y QQ entrel os pacientes con ECI fue del 60,8 por ciento, 34,4 por ciento y 4,8 por ciento, semejante a la distribución de los genotipos entre los pacientes sin ECI (64,0 por ciento, 32,7 por ciento y 3,3 por ciento, P = 0,574). No se observó diferencia en las características clínicas o de laboratorio entre los tres genotipos, ni en relación con la presencia de síndrome metabólico. CONCLUSIÓN: No se encontró ninguna asociación entre el polimorfismo K121A del gen ENPP1 y la presencia de ECI o características fenotípicas de resistencia insulínica.

The role of K121Q ENPP1 polymorphism in diabetes mellitus and its complications

The aim of the present study was to analyze the frequency of K121Q polymorphism in the ENPP1 gene of Brazilian subjects according to ethnic origin and to determine its possible association with diabetes mellitus (DM) and/or diabetic complications. A cross-sectional study was conducted on 1027 type 2 DM patients and 240 anonymous blood donors (BD). Ethnicity was classified based on self-report of European and African descent. The Q allele frequency was increased in African descendant type 2 DM patients (KK = 25.9 percent, KQ = 48.2 percent, and QQ = 25.9 percent) and BD (KK = 22.0 percent, KQ = 53.8 percent, and QQ = 24.2 percent) compared to European descendant type 2 DM patients (KK = 62.7 percent, KQ = 33.3 percent, and QQ = 4.1 percent) and BD (KK = 61.0 percent, KQ = 35.6 percent, and QQ = 3.4 percent). However, there was no difference in genotype distribution or Q allele frequency between diabetic and non-diabetic subjects (European descendants: DM = 0.21 vs BD = 0.21, P = 0.966, and African descendants: DM = 0.50 vs BD = 0.51, P = 0.899). In addition, there were no differences in clinical, laboratory or insulin resistance indices among the three genotypes. The prevalence of DM complications was also similar. In conclusion, K121Q polymorphism is more common among Afro-Brazilian descendants regardless of glycemic status or insulin sensitivity indices. Likewise, insulin sensitivity and DM chronic complications appear not to be related to the polymorphism in this sample.

Comparison of inosine triphate pyrophosphatase gene expression in chronic myelogenous leukemia patients and controls

One of the most significant damages to the genetic material is oxidative deamination of DNA and free nucleotides in the cell pool. Incorporation of deaminated purine nucleotides such as inosine triphosphate [ITP, dITP] into the DNA can increase the frequency of base substitution mutation. It has been suggested that presence and accumulation of these rough nucleotides can lead to genetic instability which is the perquisite of different types of diseases or cancers. Inosine triphosphaate pyrophosphates [ITPase/] encoded by ITPA gene, is responsible for protecting the cells by omitting deaminated purines from the free nucleotide pool. The objective of this study was to examine the possible dysfunction of ITPA gene activity as an important factor in genetic background predisposing to chromosomal disorders and malignancies such as CML. ITPA gene expression study performed on 23 CML patients and 21 controls using semi-quantitative RT-PCR technique and the expression level of GAPDH gene was used as an internal control. Unusual variants obtained from cDNA amplification of ITPA gene were clones. Our results showed a significant reduction of ITPA gene expression in CML patients in comparison to the controls. Two types of transcripts were produced in addition of expected transcript in some samples. One of them had a 123 nucleotide and the other had 77 nucleotide deletions in their open reading frame. Due to decreased expression of ITPA gene; it seems that the function of ITPase is not normal in CML patients. Therefore the altered expression of this gene can be considered as an additive factor for genetic instability in these patients

Association of the polymorphism of codon 121 in the ecto-nucleotide pyrophosphatase/phosphodiesterase 1 gene with polycystic ovary syndrome in Chinese women

To determine the association of polymorphism of codon 121 in the ecto-nucleotide pyrophophastase/phosphodiesterase 1 [E-NPP1/PC-1] gene in Chinese women with polycystic ovary syndrome [PCOS]. A total of 51 PCOS patients and 61 healthy women from the Chinese Han population from the Center Reproductive Medicine of Provincial Hospital affiliated to Shandong University from June 2005 to July 2006 were recruited for the determination of the polymorphism of the E-NPP1/PC-1 gene. Genomic DNA was extracted from peripheral blood monocytes of patients and controls, and genotyping of the gene was performed by using polymerase chain reaction, which was followed by sequencing. The frequency of the 121Q allele was 13 and 18%, respectively, in PCOS patients and healthy women, while the frequency of the 121K allele was 87 and 82% in the 2 groups. There is no significant difference in the E-NPP1/PC-1 polymorphism between PCOS patients and healthy controls among Chinese Han women. Ecto-nucleotide pyrophophastase/phosphodiesterase 1 polymorphism has no association with PCOS. Further studies are still needed to elucidate whether or not the E-NPP1/PC-1 gene has a functional role in PCOS

The K121Q Polymorphism in ENPP1 (PC-1) Is Not Associated with Type 2 Diabetes or Obesity in Korean Male Workers

Type 2 diabetes is characterized by insulin resistance, and ENPP1 plays an important role in insulin resistance. We investigated the association of the ENPP1 K121Q polymorphism with both diabetes and obesity (body mass index [BMI]) in Korean male workers. The study design was case-control. Subjects were 1,945 male workers (type 2 diabetes, 195; non-diabetes, 1,750) of nuclear power plants who received examinations from March to October in 2004. We collected venous blood samples under fasting (> or =8 hr) conditions, calculated BMI by height and weight, and assessed relevant biochemical factors. The results of this study demonstrated that the ENPP1 121Q genotype (KQ+QQ types) was not associated with type 2 diabetes (odds ratios [OR], 0.854; 95% confidence interval [CI], 0.571-1.278) or obesity (OR, 0.933; 95% CI, 0.731-1.190). In addition, the frequency of the Q allele was not related to type 2 diabetes (OR, 0.911; 95% CI, 0.630-1.319) or obesity (OR, 0.962; 95% CI, 0.767-1.205). We concluded that the ENPP1 121Q allele is not a critical determinant for either diabetes or obesity in Korean males. The discordance between the results of this study and those derived from studies of Dominican, South Asian, Caucasian, Finnish, and French populations might be due to differences in genetic backgrounds between these populations.

Genetic predisposition to type 2 diabetes among Asian Indians.

Genes play an important role in the development of diabetes mellitus. Type 2 diabetes is a polygenic disorder with multiple genes located on different chromosomes contributing to its susceptibility. Analysis of the genetic factors is further complicated by the fact that numerous environmental factors interact with genes to produce the disorder. Only a minority of cases of type 2 diabetes are caused by single gene defects and one example is maturity onset diabetes of the young (MODY). Till date knowledge of the genetics of type 2 diabetes is limited. Consistent with the complex web of physiologic defects in type 2 diabetes, the genetics of the disorder involves a large number of susceptibility genes, each with a relatively small effect. In this article, the studies on genetics of diabetes in Asian Indians are reviewed. As Asian Indians have an increased susceptibility to diabetes and have increased insulin resistance, they are a unique population for carrying out genetic studies. There appears to be certain genes which predispose Indians to diabetes while other genes (for example Pro 12 Ala polymorphism of PPAR gamma gene) which afford protection against diabetes and insulin resistance to Caucasians, do not appear to protect Indians. Further studies are needed to unravel the genetics of diabetes in South Asians .