DNA polymorphisms of the insulin receptor gene in Japanese subjects with non-insulin-dependent diabetes mellitus

Genotypes identified by two restriction fragment length polymorphisms (RFLPs) of the insulin receptor gene (IRG) with the restriction endonuclease Sst-1 were determined in a Japanese group comprising 51 patients with non-insulin-dependent diabetes mellitus (NIDDM) and 50 control subjects. Southern hybridization using a probe for the beta subunit of the human IRG identifies 4 alleles, termed S1(+) (5.3 kb), S1(-) (5.8 kb), S2(+) (7.0 and 2.4 kb) and S2(-) (9.4 kb). The frequencies of genotypes possessing the S1(-) allele in Japanese controls and Japanese NIDDM patients were 0.11 and 0.16, respectively. Unlike the previously reported association of the S1(-) allele with NIDDM found in Caucasians there was no significant difference in the frequency of the S1(-) allele between non-diabetic and NIDDM Japanese patients. There was a significant difference in the frequency of the S2(+) allele between Caucasian control subjects (0.14) and Japanese controls (0.0) and NIDDM patients (0.02).     

haplotypes identified by DNA polymorphisms at the apolipoprotein A-1 and C-III loci and hypertriglyceridaemia

Summary A Japanese group comprising 40 hypertriglyceridaemic and 35 normolipidaemic subjects were genotyped for two intragenic DNA restriction fragment length polymorphisms (RFLPs) at the A-1 and C-III gene loci. An Sst-1 polymorphism is located at the 3 end of the C-III gene and a Msp-1 polymorphism in the third intron of the A-1 gene. The polymorphic restriction sites are 3.8kb apart. The polymorphism with Sst-1 was present at allelic frequencies of 0.67 (S1 allele) and 0.33 (S2 allele), and the polymorphism with Msp-1 was present at allelic frequencies of 0.55 (M1 allele) and 0.45 (M2 allele). The alleles S1, S2, M1, and M2 are in linkage disequilibrium and three haplotypes were identified S1-M1, S1-M2, and S2-M2. Unlike the previously reported association of the S2 allele with hypertriglyceridaemia found in Caucasians there was no difference in the frequency of S2 allele between normolipidaemic and hyperlipidaemic Japanese. However one of the haplotypes S1-M2 was significantly increased in the hypertriglyceridaemic subjects (32% versus 11% P>0.025). Thus in Japanese there is an association with genotypes at this locus and hypertriglyceridaemia but with a different haplotype than in Caucasians.     

APOC3基因SstⅠ单核苷酸多态性与冠心病、Ⅱ型糖尿病合并高甘油三酯血症的关联性研究

对许多人群研究表明 ,位于APOA1/C3/A4 /A5基因簇上的载脂蛋白C3基因 (APOC3)SstⅠ多态性与高甘油三酯血症 (Hypertriglyceridaemia ,HTG)密切相关 ,高甘油三酯是冠心病和糖尿病的独立危险因素。为探讨中国人群APOC3基因SstⅠ单核苷酸多态性与冠状动脉粥样硬化性心脏病 (coronaryatheroscleroticheartdisease,CHD)合并高甘油三酯血症 (HTG)、Ⅱ型糖尿病 (non insulin dependentdiabetesmellitus,NIDDM)合并高甘油三酯血症 (HTG)患者的相关性 ,应用聚合酶链反应 限制性片段长度多态性 (PCR RFLP)的方法 ,分析了 2 6 7例CHD患者、2 4 6例NIDDM患者及 4 91例健康对照APOC3基因SstⅠ位点 (S1/S2 )多态性。CHD组、NIDDM组和对照组的APOC3基因SstⅠ多态位点S2等位基因频率分别为 0 30 1、0 30 7和 0 2 86 ,其基因型频率和等位基因频率分布与对照组比较均无显著性差异 (P >0 0 5 )。以TG >1 90mmol/L为标准将CHD组、NIDDM组分为正常甘油三酯组 (NTG)和高甘油三酯组(HTG)发现 ,在CHD患者 ,HTG亚组S1S2基因型频率显著高于NTG亚组 (0 5 4 2 >0 35 7,χ2 =8 77,P =0 0 12 4 ) ;在NIDDM患者 ,HTG亚组S2S2基因型频率显著高于NTG亚组 (0 2 0 0 >0 0 5 5 ,χ2 =2 0 2 1,P =0 0 0 0 0 ) ,两亚组间等位基因频     

The interleukin-6 (-174) G/C promoter polymorphism is associated with type-2 diabetes mellitus in Native Americans and Caucasians

Chronic low-grade activation of the immune system may play a role in the pathogenesis of type-2 diabetes mellitus (T2DM). Interleukin-6 (IL6), a powerful inducer of hepatic acute phase response, has been implicated in the etiology of insulin resistance and T2DM. Recently, an IL6 promoter polymorphism (G/C) at position -174 was found to be associated with measures of insulin sensitivity. Because we have previously found an association between high IL6 levels and insulin resistance in both Pima Indians - a population with high rates of insulin resistance and T2DM - and Caucasians, we aimed to assess whether the IL6 promoter polymorphism is associated with T2DM in these populations. We genotyped the IL6 (-174) G/C polymorphism using pyrosequencing in 463 Native Americans and by PCR-RFLP in 329 Spanish Caucasians. Among the Spanish Caucasian subjects, there was a significant difference in genotypic distribution between diabetic and non-diabetic subjects (P=0.028); the GG genotype was more common in diabetic (0.40) than in non-diabetic (0.29) subjects. The G allele was much more frequent in the Native American sample, and among a sample of 143 cases and 145 controls, the GG genotype was significantly more common in diabetic subjects (P=0.019). When this sample population was stratified according to ethnic heritage, all 211 subjects who were of full Pima Indian heritage had the GG genotype, whereas in the 77 American Indian subjects with non-Pima admixture, T2DM was associated with IL6 genotype (P=0.001). These findings are consistent with a role for genetic determinants of inflammation in the development of T2DM in both Native Americans and Caucasians.     

广东少数民族Morquio综合征StuI位点的RFLP分析

研究广东少数民族群体GALNS基因StuI位点的遗传多态性以及该位点等位基因片段传递的规律,为今后的连锁分析打下基础。采用PCR-RFLP方法,对72例无血缘关系的健康广东少数民族个体的144条染色体和3个家系9位成员的18条染色体进行检测,然后用χ2检验进行统计学处理。等位基因片段D1的频率为0.70, D2为0.30,杂合率为29%,D1、D2的传递规律与理论上预计的完全符合。广东少数民族群体中StuI位点具有多态性,其基因频率（D1和D2）与国外高加索群体的有显著差别,与日本群体及中国南方汉族群体的则无显著差别;而杂合率与高加索群体及日本群体的均有显著差异,但与中国南方汉族群体的则无显著差异。 Abstract:To investigate the genetic polymorphism of the StuI site in the GALNS gene from a national minority population in Guangdong and to study the mode of transmission of alleles,PCR-RFLP was used to analyze 144 chromosomes from 72 Guangdong unrelated healthy national minority individuals,and the genotypes of members in three families.To compare the frequencies and heterzygosity between Guangdong national minority people and Caucasians,Japanese and Chinese Han people by using χ2 test.The frequency of allele D1(295bp) was 0.70,allele D2(138 plus 157 bp)0.30,the heterozygosity was 29%.The genotypes of each member of all families detected were completely agreement with the theorical assessment.The site of StuI in the GALNS gene from national minority population in Guangdong has polymorphism.There is significant difference between Guangdong national minority population and Caucasians in Western countries,but no significant difference was found between Guangdong national minority population and Japanese and Chinese Han population.In addition,there is significant difference between Guangdong national minority population and Caucasians and Japanese in the heterzygosity,but no significant difference between Guangdong national minority population and Chinese Han population.The transmission of alleles was completely in agreement with the Mendelian genetic law.     

Polymorphisms at the GLUT1 (HepG2) and GLUT4 (muscle/adipocyte) glucose transporter genes and non-insulin-dependent diabetes mellitus (NIDDM)

Summary In order to determine the possible contribution of the GLUT1 (HepG2) glucose transporter gene to the inheritance of non-insulin-dependent diabetes mellitus (NIDDM), two restriction fragment length polymorphisms (RFLPs) and the related haplotypes at this locus were studied in 48 Italian diabetic patients and 58 normal subjects. Genotype frequencies for the XbaI polymorphism were significantly different between patients and controls (XbaI: ² = 9.80, df= 2, P < 0.0079). A significant difference was also found in the allele frequencies between NIDDM patients and controls (² =9.39, df = 1, P < 0.0022), whereas no differences were found for the StuI RFLP. No linkage disequilibrium was detected between the XbaI and StuI RFLPs in this sample. The analysis of the four haplotype frequencies (X1S1, X1S2, X2S1, X2S2) revealed a significant difference between diabetic patients and controls (² = 14.26, df =3, P < 0.002). By comparing single haplotype frequencies, a significant difference between the two groups was found for the X1S1 and X2S2 haplotypes. A two-allele RFLP at the GLUT4 (muscle/adipocyte) glucose transporter gene, detected with the restriction enzyme KpnI, was also examined; no differences were found between patients and controls for this RFLP. The finding of an association between polymorphic markers at the GLUT1 transporter and NIDDM suggests that this locus may contribute to the inherited susceptibility to the disease in this Italian population.     

Acetaldehyde dehydrogenase 2 SNP rs671 and susceptibility to essential hypertension in Mongolians: a case control study

Mongolians are known as heavy drinkers, and they have a high incidence of essential hypertension, which may be an associated pathology. We examined a possible association of essential hypertension and polymorphism of the aldehyde dehydrogenase 2 (ALDH2) gene in Mongolians from Inner Mongolia. Single nucleotide polymorphism rs671 of ALDH2 was detected by TaqMan PCR in 91 essential hypertensive patients (44 males and 47 females) and 70 healthy Mongolians (37 males and 33 females). Frequencies of the ALDH2*1/1 genotype and the ALDH2*1 allele in patients (91.2 and 95.6%, respectively) were significantly higher than in controls (78.6 and 89.3%; P < 0.05), while frequencies of ALDH2*1/2 genotype and ALDH2*2 allele in patients (8.79 and 4.4%) were much lower than in controls (21.4 and 10.7%; P < 0.05). Frequencies of ALDH2*1/1 genotype and ALDH2*1 allele in female patients (95.8 and 94.9%) were higher than in female controls (70.0 and 84.9%; P < 0.05); frequencies of the ALDH2*1/2 genotype and the ALDH2*2 allele in female patients (4.25 and 2.13%) were lower than in female controls (30.3 and 15.2%, P < 0.05). There was no significant difference in male subjects. ALDH2*2/2 was not found in any of the subjects. We conclude that ALDH2 polymorphism is associated with essential hypertension in Mongolians, especially in female Mongolians. ALDH2*2 was found to be a negative risk factor for essential hypertension in Mongolians from Inner Mongolia.     

Polymorphism analysis of the CYP1A1 locus in Koreans: presence of the solitary m2 allele

This study determined the complete genotype and the frequencies of all four mutations [T6235C (m1), A4889G (m2), T5639C (m3) and C4887A (m4)] of the CYP1A1 from 48 healthy Koreans and 17 Korean lung cancer patients. The mutations were analyzed by polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) and single stand conformation polymorphism (SSCP) simultaneously in order to improve accuracy as well as to screen for possible new alleles. Previously, the m2 mutation has always been linked to the m1 mutation. Also, the m1m2 double mutant allele (*2B) was thought to have a positive correlation with lung cancer susceptibility. Here we report the presence of the solitary m2 mutant allele without the m1 mutation (m1+m2) for the first time. This would be an evidence to support the theory of intragenic recombination in the CYP1A1 locus. The m1 mutation frequencies of healthy Koreans and lung cancer patients were 38.5% and 29.4%, respectively. The m2 mutation frequencies of healthy Koreans and lung cancer patients were 25.0% and 14.7%, respectively. Unlike the case for both Japanese and Caucasian lung cancer patients, neither m1 nor m2 mutations were overrepresented in Korean lung cancer patients. The m2 mutation frequency in Korean patients was significantly higher than those for Caucasians (2.7%) and the Japanese (19.8%). The African-American specific m3 mutation and m4 mutation found in Caucasians were not discovered in this study. The CYP1A1 allele with novel mutation was also not present.     

Association of lipoprotein lipase and apolipoprotein C-III genes polymorphism with acute myocardial infarction in diabetic patients

Lipoprotein lipase (LPL) and Apolipoprotein C-III (APOC-III) play an important role in lipid metabolism. The aim of this study was to explore the possible associations of the gene polymorphisms (LPL HindIII, LPL Ser(447)-Ter and APOC3 SstI), diabetes mellitus, and plasma lipids with myocardial infarction. The polymorphisms were assessed by restriction assay in 200 Egyptian MI patients (100 diabetic and 100 non-diabetic) and 100 healthy controls. This study demonstrated that individuals with the H2H2 genotype or S2 allele have more than three times higher relative risk of suffering from MI than those carrying the H1H1 or S1S1. Type 2 DM mainly lowers HDL-C levels in MI patients who carry H2H2 or S2S2 genotype and increases TC, TG, and LDL levels in MI patients carrying H2H2 or S2S2 genotype compared with non-diabetic MI patients carrying the same genotypes. In S447X polymorphism, it was observed that DM led to loss of the protective lipid profile in MI patients carrying 447XX genotype. These findings suggest that H2H2 or S2S2 genotypes are associated with dyslipidemia and increased risk of myocardial infarction. The S447X polymorphism is associated with a favorable lipid profile. However, the association of diabetes mellitus with these polymorphisms leads to unfavorable lipid profile.     

The C1167T polymorphism of the catalase gene and polymorphic markers D11S907 and D11S2008 located in its vicinity are associated with diabetes mellitus type 2

To study the contribution of the catalase (CAT) gene in diabetes mellitus (DM) type 2, the allele and genotype frequencies of internal (polymorphism C1167T) and two neighboring (minisatellites D11S907 and D11S2008) polymorphic markers were studied in 132 healthy individuals and 154 patients from Moscow. Allele C and genotype CC of the C1167T polymorphism proved associated with a higher risk of DM type 2. Seven D11S907 alleles containing 14 to 20 dinucleotide repeats were found. The frequencies of alleles 15 and 16 and genotype 18/20 were significantly higher and those of allele 18 and genotypes 17/18 and 18/19 were lower in patients than in controls. Eight D11S2008 alleles containing 15 to 22 tetranucleotide repeats were found. The frequencies of alleles 17 and 18 and genotype 18/20 in patients were significantly higher than in controls. An association of the three polymorphic loci and DM type 2 was suggested.     

TGF-beta1 基因rs200482214 位点多态性与黑龙江省汉族人群慢性牙周炎的相关性研究

目的:探讨转移生长因子β1(transforminggrowth factor beta-l,TGF-β1)位点rs200482214基因多态性与黑龙江省汉族人群慢性牙周炎的易感性的相关性。方法:选取2012年3月至2013年7月在哈尔滨医科大学附属口腔医院牙周科就诊的135例轻、中、重度慢性牙周炎汉族患者(牙周炎组)和108例汉族健康对照者(健康对照组)作为研究对象,基因组DNA来自口腔颊粘膜拭子,采用多重单碱基延伸SNP分型技术(Multiplex SNaPshot technique)对所有受试者TGF-β1基因rs200482214位点进行检测,比较两组间此位点基因型分布和等位基因频率的差异。结果:(1)TGF-β1基因rs200482214位点各基因型(GG、GA、AA)分布均符合Hardy-Weinberg遗传平衡定律(P>0.05);(2)TGF-β1基因rs200482214位点GG、GA、AA在牙周炎组和健康对照组的分布频率分别为61.5%、30.4%、8.1%和63.0%、28.7%、8.3%,两组人群基因型分布频率差异无统计学意义(P>0.05);等位基因G、A在牙周炎组和健康对照组分布频率分别为76.7%、23.3%和77.3%、22.7%,两组人群的等位基因分布频率差异亦无统计学意义(P>0.05)。结论:TGF-β1位点rs200482214基因多态性与黑龙江省汉族人群慢性牙周炎的易感性不具有相关性。     

Chemotactic cytokine receptor 5 gene polymorphism: relevance to microvascular complications in type 2 diabetes

We investigated the involvement of chemotactic cytokine receptor 5 (CCR5) gene polymorphism in microvascular complications of T2DM. All subjects were genotyped with the 59029 SNP in the CCR5 gene. The genotype/allele frequencies did not differ between T2DM patients and controls. Genotype distribution was compared in patients with and without complications (nephropathy, retinopathy and neuropathy). The frequency of A allele was significantly higher in patients with complications (OR for A allele 3.07, 95% CI 2.49-3.77). The A allele carriage was associated with diabetic nephropathy (OR 6.17, 95% CI 3.28-11.6). An association was observed between 59029 polymorphism and age at T2DM onset. The A allele was more frequent in early onset than in late onset patients. For AA homozygotes OR was 2.38 (1.19-4.76) and 2.26 (1.12-4.58) in complicated and uncomplicated subgroups, respectively. These results suggest that CCR5 gene polymorphism is associated with diabetic nephropathy in T2DM.     

Genetic polymorphism c.1562C>T of the MMP-9 is associated with macroangiopathy in type 2 diabetes mellitus

Objective

To determine whether the matrix metalloproteinase-9 (MMP-9) c.1562C>T polymorphism has an effect on the plasma MMP-9 levels and the macroangiopathic complications in type 2 diabetes mellitus (T2DM).

Methods

The genotypes and allelic frequencies of the MMP-9 c.1562C>T were examined with polymerase chain reaction and restriction fragment length polymorphism in 320 patients with T2DM and 160 unrelated healthy subjects. The plasma concentrations of MMP-9 were determined in all subjects.

Results

The mean plasma concentrations of MMP-9 of patients with T2DM were significantly higher than that of controls and the plasma levels of MMP-9 were higher in diabetic patients with macroangiopathy than in patients without macroangiopathy (P < 0.05). The genotype (CC, CT, and TT) distribution of c.1562C>T polymorphism of the MMP-9 gene was 60.0%, 31.3%, and 8.8% in diabetic patients with macroangiopathy, 76.3%, 21.3%, and 2.5% in patients without macroangiopathy, and 77.5%, 21.3%, 1.3% in controls, respectively, a significant difference was found between diabetic patients with and without macroangiopathy (P < 0.05). The frequency of the allele T was higher in patients with macroangiopathy than in patients without macroangiopathy (24.4% vs 13.1%; P < 0.05). Moreover, the plasma MMP-9 levels were markedly higher in patients with TT genotype than those with CC or CT genotype in patients with macroangiopathy (P < 0.05).

Conclusion

The MMP-9 c.1562C>T gene polymorphism associated with a predisposition to increased plasma MMP-9 levels could constitute a useful predictive marker for diabetic macroangiopathy.     

Novel alleles of 31-bp VNTR polymorphism in the human cystathionine β-synthase (<Emphasis Type="Italic">CBS</Emphasis>) gene were detected in healthy Asians

A 31-bp variable number of tandem repeats (VNTR) polymorphism of the cystathionine β-synthase (CBS) gene was earlier reported in Caucasians of predominantly European descent and Indo-Caucasoid populations.We report here for the first time, the detection of allele 20, which was absent in Caucasian and Indo-Caucasoid populations, as a common allele present in Singaporean Chinese (6.25%), Indians (11.7%), and Malays (11.5%). Hence, allele 20 might be a specific allele for Asian populations. A relatively common allele 19 found in the Caucasian and Indo-Caucasoid populations (10.4%–10.6%) was absent in the Asian samples of this study. Therefore, allele 19 might be a specific allele for the Caucasian populations. A novel and rare allele 13, which was not reported before in the Caucasian and Indo-Caucasoid populations, was found in 0.5% of Singaporean Chinese as genotype 13/17 heterozygotes. The presence of alleles 13 and 20 were verified by DNA sequencing. There were five new genotypes (13/17, 16/20, 17/20, 18/20 and 20/20) not reported before in the Caucasian and Indo-Caucasoid populations, detected in this study. Nine genotypes (15/18, 16/18, 16/21, 17/19, 18/19, 18/21, 19/19, 19/21 and 21/21) which were present in the Caucasian and/or Indo-Caucasoid populations were absent in this study. Our results showed that CBS 31-bp VNTR polymorphism has a distinct genetic difference in allele and genotype frequencies between the European Caucasians, Indo-Caucasoid and Asian populations.     

Genotype frequencies of polymorphic GSTM1, GSTT1, and cytochrome P450 CYP1A1 in Mexicans

The genotype frequencies of three metabolic polymorphisms were determined in a sample of a typical community in central Mexico. CYP1A1*3, GSTM1, and GSTT1 polymorphisms were studied in 150 donors born in Mexico and with Mexican ascendants; with respect to ethnicity the subjects can be considered Mestizos. PCR reactions were used to amplify specific fragments of the selected genes from genomic DNA. An unexpected 56.7% frequency of the CYP1A1*3 allele (which depends on the presence of a Val residue in the 462 position of the enzyme, instead of Ile) was found, the highest described for open populations of different ethnic origins (i.e., Caucasian, Asian, African, or African American). The GSTM1 null genotype was found with a frequency of 42.6%, which is not different from other ethnicities, whereas the GSTT1 null genotype had a frequency of 9.3%, one of the lowest described for any ethnic group but comparable to the frequency found in India (9.7%). The frequency of the combined genotype CYP1A1*3/*3 and the GSTM1 null allele is one of the highest observed to date (or perhaps the highest): 13.7% among all the ethnicities studied, including Caucasians and Asians, whereas the combination of CYP1A1*3/*3 with the GSTT1 null allele reached only 2.8%. The GSTM1 null allele combined with the GSTT1 null allele, on the other hand, has one of the lowest frequencies described, 4.24%, comparable to the frequencies found in African Americans and Indians. Finally, the combined CYP1A1*3/*3, GSTM1 null allele, and GSTT1 null allele genotype could not be found in the sample studied; it is assumed that the frequency of carriers of these combined genotypes is less than 1%. CYP1A1*3 and CYP1A1*2 polymorphisms were also evaluated in 50 residents in a community of northern Mexico; the CYP1A1*3 frequency was 54%, similar to that found in the other community studied, and the CYP1A1*2 frequency was 40%, which is high compared to Caucasians and Asians but comparable to the frequency found in Japanese and lower than the frequency found in Mapuche Indians. Haplotype frequencies for these CYP1A1 polymorphisms were estimated, and a linkage disequilibrium value (D) of 0.137 was calculated.     

瘦素受体基因Lys109Arg 多态性与慢性阻塞性肺疾病营养状况的关系

目的:探讨瘦素受体基因Lys109Arg多态性与慢性阻塞性肺疾病营养状况的关系。对象与方法:观察159例COPD稳定期患者及110例健康对照者体重指数(BMI)、理想体重百分比(NW%)、三头肌皮皱厚度(TSF)、上臂中点臂围(MAC)、血清白蛋白(ALB)、总淋巴细胞(LYM)等营养参数,将COPD组分为营养不良组(COPD1组)68例,COPD非营养不良组(COPD2组)91例。用酶联免疫吸附试验(ELISA)法测定血清瘦素水平,采用聚合酶链式反应及连接酶检测反应方法(PCR-LDR)测定瘦素受体Lysl09Arg多态性的基因型。结果:COPD1组Lys109Arg基因型GG、GA及AA的频率分别为0.838、0.147和0.015,G和A等位基因分别为0.912和0.088;COPD2组Lys109Arg基因型GG、GA及AA的频率分别为0.67、0.319和0.011,G和A等位基因分别为0.83和0.17;对照组Lys109Arg基因型GG、GA及AA的频率分别为0.7、0.273和0.027,G和A等位基因分别0.841和0.159;COPD1组Lys109Arg基因型及等位基因频率与COPD2组和对照组比较差异有显著性;COPD2组和对照组比较差异无显著性。GG型受试者血清瘦素水平低于A/G型+AA型(39.08±15.79ng/ml vs 43.29±17.25ng/ml),但差异无统计学意义。结论:瘦素受体基因Lys109Arg多态性可能与COPD营养状况相关。     

Ala-9Val polymorphism of Mn-SOD gene in sickle cell anemia

Oxidative stress may be contributory to the pathophysiology of the abnormalities that underlie the clinical course of sickle cell anemia. We looked for a possible genetic association between the functional polymorphism Ala-9Val in the human Mn-SOD gene and sickle cell anemia. One hundred and twenty-seven patients with sickle cell anemia and 127 healthy controls were recruited into the study. Alanine versus valine polymorphism in the signal peptide of the Mn-SOD gene was evaluated using a primer pair to amplify a 107-bp fragment followed by digestion with the restriction enzyme NgoMIV. In the sickle cell anemia patients, the frequency of Val/Val genotype was approximately 1.4-fold lower and that of Ala/Val was 1.3-fold higher compared to the controls. No significant difference in genotype frequencies was found between patients and controls (χ(2) = 4.561, d.f. = 2, P = 0.101). The Val-9 was the most common allele in patient and healthy subjects. No significant difference in allele frequencies was found between patients and controls (χ(2) = 1.496, d.f. = 1, P = 0.221). We conclude that the Mn-SOD gene polymorphism is not associated with sickle cell anemia.     

Lack of association between an ecNOS gene polymorphism and diabetic nephropathy in type 2 diabetic patients with proliferative diabetic retinopathy.

The development of diabetic nephropathy shows remarkable variation among individuals. Therefore, not only hyperglycemia but also genetic factors may contribute to the development of diabetic nephropathy. The aim of the present study was to examine the contribution of the 27-bp repeat polymorphism in intron 4 of the endothelial constitutive nitric oxide synthase gene (ecNOS4) to the development of diabetic nephropathy. For this purpose, we analyzed this polymorphism in 167 Japanese type 2 diabetic patients with proliferative diabetic retinopathy consisting of 102 patients with diabetic nephropathy (with macroalbuminuria) and 65 patients without diabetic nephropathy (with normoalbuminuria). The genotype and allele frequencies were not significantly different between patients with diabetic nephropathy and those without diabetic nephropathy (ecNOS4 "b/b" 79.4% vs. 84.6%, ecNOS4 "b/a" 20.6% vs. 15.4%, "b" allele 89.7% vs. 92.3%, "a" allele 10.3% vs. 7.7%). We conclude that the ecNOS4 polymorphism does not contribute to the development of diabetic nephropathy.     

The 223A>G polymorphism of the leptin receptor gene is associated with macroangiopathy in type 2 diabetes mellitus

To determine whether leptin receptor (LEPR) 223A>G polymorphism has an effect on the plasma leptin levels and the macroangiopathic complications in type 2 diabetes mellitus (T2DM). The genotypes and allelic frequencies of the LEPR 223A>G were examined with polymerase chain reaction and restriction fragment length polymorphism in 301 patients with T2DM and 172 unrelated healthy subjects. The plasma concentrations of leptin were determined in all subjects. The mean plasma leptin levels in the T2DM group were significantly higher than that of controls and the plasma levels of leptin were higher in diabetic patients with macroangiopathy than in patients without macroangiopathy (P < 0.05). The genotype (GG, AG and AA) distribution of 223A>G polymorphism was 58.3, 32.5, and 9.2% in diabetic patients with macroangiopathy, 75.3, 22.1, and 2.6% in patients without macroangiopathy, and 70.3, 27.5, 2.2% in controls respectively, a significant difference was found between diabetic patients with and without macroangiopathy (P < 0.05). The frequency of the allele A was higher in patients with macroangiopathy than in patients without macroangiopathy (25.6 vs. 16.3%; P < 0.05). Moreover, the plasma leptin levels were markedly higher in patients with AA genotype than those with AG or GG genotype in patients with macroangiopathy (P < 0.05). The LEPR 223A>G gene polymorphism associated with a predisposition to increased plasma leptin levels could constitute a useful predictive marker for diabetic macroangiopathy.