Clinical differences between patients with MODY-3, MODY-2 and type 2 diabetes mellitus with I27L polymorphism in the HNF1α gene

ObjectiveThe aim of our study was to describe and evaluate the clinical and metabolic characteristics of patients with MODY-3, MODY-2 or type 2 diabetes who presented I27L polymorphism in the HNF1α gene.MethodsThe study included 31 previously diagnosed subjects under follow-up for MODY-3 (10 subjects from 5 families), MODY-2 (15 subjects from 9 families), or type 2 diabetes (6 subjects) with I27L polymorphism in the HNF1α gene. The demographic, clinical, metabolic, and genetic characteristics of all patients were analyzed.ResultsNo differences were observed in distribution according to sex, age of onset, or form of diagnosis. All patients with MODY-2 or MODY-3 had a family history of diabetes. In contrast, 33.3% of patients with type 2 diabetes mellitus and I27L polymorphism in the HNF1α gene had no family history of diabetes (p < 0.05). No differences were observed in body mass index, prevalence of hypertension, or microvascular or macrovascular complications. Drug therapy was required by 100% of MODY-3 patients, but not required by 100% of MODY-2 patients or 16.7% of patients with type 2 diabetes mellitus and I27L polymorphism in the HNF1α gene (p < 0.05).ConclusionsOccasional difficulties may be encountered when classifying patients with MODY-2, MODY-3 or type 2 diabetes of atypical characteristics, in this case patients who present I27L polymorphism in the HNF1α gene.     

RsaI polymorphism of the ERβ gene in women with endometriosis

We examined the frequency of RsaI polymorphism of the ERβ gene in 54 patients diagnosed with endometriosis and 46 controls. Peripheral blood was collected from women undergoing laparoscopy with a confirmed diagnosis of endometriosis. Polymorphisms of the ERβ gene and p53 were assessed by PCR and analyzed on 2% agarose gel stained with ethidium bromide. The AG polymorphism genotype frequency in patients with endometriosis was 59.3%, with 40.7% GG. In the control group, the frequency of AG was 6.5%, with 93.5% GG. The frequency of heterozygous AG was nine times higher in patients with endometriosis than in the control group (P < 0.0001).     

Association of peroxisome proliferator-activated receptor γ Pro12Ala gene polymorphism with type 2 diabetic nephropathy risk in Caucasian population

Abstract

Association of peroxisome proliferator-activated receptor gamma (PPARγ) Pro12Ala gene polymorphism with type 2 diabetic nephropathy (T2DN) risk in Caucasians is still not clear. This investigation was conducted to assess if there was an association between the PPARγ Pro12Ala gene polymorphism and T2DN risk in Caucasians using meta-analysis. The relevant literatures were identified from PubMed, and Cochrane Library on 10 October 2013, and eligible studies were included and synthesized. Six reports including eight studies were recruited into this meta-analysis for the association of the PPARγ Pro12Ala gene polymorphism with T2DN risk in Caucasians. The Pro/Pro genotype was shown to be associated with T2DN risk in Caucasians. However, the Ala/Ala genotype and Ala allele were not associated with T2DN risk in Caucasians. In the sensitivity analysis, according to the control source from hospital, the control source from population, the genotyping methods using PCR-RFLP, Taqman, sample size of case <100, the association of the PPARγ Pro12Ala gene polymorphism with T2DN risk was similar to those in non-sensitivity analysis. In conclusion, the PPARγ Pro/Pro genotype was associated with T2DN risk in Caucasians, but the Ala/Ala genotype and Ala allele not. However, additional studies are required to firmly establish a correlation between the PPARγ Pro12Ala gene polymorphism and T2DN risk in Caucasians.     

Screening of mitochondrial mutations and insertion–deletion polymorphism in gestational diabetes mellitus in the Asian Indian population

In this study we scrutinized the association between the A8344G/A3243G mutations and a 9-bp deletion polymorphism with gestational diabetes mellitus (GDM) in an Asian Indian population. The A3243G mutation in the mitochondrial tRNA^Leu(UUR) causes mitochondrial encephalopathy myopathy, lactic acidosis, and stroke-like episodes (MELAS), while the A8344G mutation in tRNA^Lys causes myoclonus epilepsy with ragged red fibers (MERRF). We screened 140 pregnant women diagnosed with GDM and 140 non-GDM participants for these mutations by PCR-RFLP analysis. Both A3243G and A8344G were associated with GDM (A3243: OR-3.667, 95% CI = 1.001–13.43, p = 0.03; A8344G: OR-11.00, 95% CI = 0.6026–200.8, p = 0.04). Mitochondrial DNA mutations contribute to the development of GDM. Our results conclude that mitochondrial mutations are associated with the GDM women in our population. Thus it is important to screen other mitochondrial mutations in the GDM women.     

Relationship between PPARγ Pro12Ala gene polymorphism and type 2 diabetic nephropathy risk in Asian population: results from a meta-analysis

Abstract

The relationship between peroxisome proliferator-activated receptor gamma (PPARγ) Pro12Ala gene polymorphism and type 2 diabetic nephropathy (T2DN) risk in Asians is still unclear. This study was performed to evaluate if there was an association between the PPARγ Pro12Ala gene polymorphism and T2DN risk in Asians using meta-analysis. The relevant reports were searched and identified from PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) on 1 October 2013, and eligible studies were included and synthesized. Ten reports were recruited into this meta-analysis for the association of the PPARγ Pro12Ala gene polymorphism with T2DN risk. The Pro12Ala gene polymorphism in the Asian population was shown to be not associated with T2DN risk (Ala/Ala: OR?=?0.67, 95% CI: 0.22–2.00, p?=?0.47; Pro/Pro: OR?=?1.77, 95% CI: 0.82–1.65, p?=?0.39; Ala allele: OR?=?0.74, 95% CI: 0.47–1.16, p?=?0.19). In the sensitivity analysis according to Hardy-Weinberg equilibrium (HWE), the control source from hospital, the control source from population, the genotyping methods using PCR-RFLP, the genotyping methods using Taqman, sample size of case (≥100), the association of the PPARγ Pro12Ala gene polymorphism with T2DN risk was also not found. Interestingly, in the sensitivity analysis according to sample size of case (<100), Ala allele was associated with T2DN risk, but not the Pro/Pro genotype. However, the sample size for sensitivity analysis according to sample size of case (<100) was relatively small and therefore, the results should be interpreted with care. In conclusion, the PPARγ Pro12Ala gene polymorphism was not associated with T2DN risk in Asians. However, Ala allele was associated with T2DN risk when the sample size of case was less than 100. Nonetheless, additional studies are required to firmly establish a correlation between the PPARγ Pro12Ala gene polymorphism and T2DN risk in Asians.     

Quantitative evaluation of common polymorphism (rs1801282) in the PPARγ2 gene and hypertension susceptibility

The peroxisome proliferator-activated receptor-γ2 (PPARγ2) gene has been implicated in the etiology of hypertension. However, the results have been inconsistent. In this study, a meta-analysis was performed to assess the association of PPARγ2 rs1801282 polymorphism with hypertension risk. Published literature from PubMed, Embase databases, CNKI and Wanfang Data were retrieved. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model. Eight studies (1865 cases and 1416 controls) for rs1801282 polymorphism were identified. The results suggested that rs1801282 polymorphism Ala allele might be protective for hypertension among East Asians (Ala/Ala+Pro/Ala vs. Pro/Pro: OR=0.63, 95%CI 0.46-0.86) but not among Caucasians (Ala/Ala+Pro/Ala vs. Pro/Pro: OR=0.72, 95%CI 0.38-1.38). The results indicated the significant association of PPARγ2 rs1801282 polymorphism with hypertension susceptibility among East Asians.     

Analysis of the rs12720208 single-nucleotide polymorphism of the FGF20 gene in Russian patients with sporadic Parkinson’s disease

Parkinson??s disease (PD) is a multifactorial neurodegenerative disease whose pathogenesis involves a number of genes and environmental factors. The FGF20 gene encoding the fibroblast growth factor and paying an important role neuron proliferation and survival is one of candidate genes of PD. There is evidence that this gene is also involved in the control of ??-synuclein (SNCA) gene expression. The rs12720208 single-nucleotide polymorphism (SNP) in the FGF20 gene has been found to be associated with PD; it has been located to the 3??-UTR binding site for microRNA-433, which is involved in the control of FGF20 expression. Therefore, the frequency distribution of rs12720208 genotypes in the FGF20 gene has been analyzed in a sample of patients with sporadic PD and a control sample of the Russian population. The results have not shown any effect of rs12720208 in the FGF20 gene on the risk of PD in patients residing in Russia (OR = 0.95, the 95% confidence interval (CI) is 0.55?C1.63, p = 0.9).     

Association of TNF-α and PTPN22 SNPs with the risk and clinical outcome of type 1 diabetes

Type 1 Diabetes mellitus (T1DM) begins with aberrant inflammatory process followed by auto-destruction in genetically susceptible individuals. Therefore, we hypothesized that gain-of-function allelic variants TNF-α-238A, -308A and PTPN22 1858T could be associated not only with T1DM development but also with the clinical outcome in patients of Bosnia and Herzegovina. A total of 402 subjects were enrolled in the association study. SNPs were determined by PCR-RFLP. Data was analyzed by GraphPad Prism and Sigma Stat 3.5 software. Genotypes frequencies at TNF-α-238 and -308 loci were not statistically different between patients and controls. In contrast, distribution of genotypes at the 1858 position of PTPN22 was significantly different, due to higher frequency of gain-of-function gene variants in patients than controls. Moreover, long term glucose regulation (based on HbA1c level) was significantly worse in patients with the risk TNF-α-308A allele than in patients with non-risk (G) allele. However, patients with the risk allele of both genes (TNF-α-308A and PTPN22 1858T) had the worst glycemic control, suggesting that those two work synergistically. In conclusion, in a cohort from Bosnia and Herzegovina TNF-α-308A allele is significantly associated with the worse long-term glucose control, but PTPN22 1858T allele is significantly associated with diabetes development.     

TRAILR1 (rs20576) and GRIA3 (rs12557782) are not associated with interferon-β response in multiple sclerosis patients

Molecular Biology Reports - Multiple sclerosis (MS) is an autoimmune-type inflammatory disorder in human central nervous system. Recombinant interferon beta (IFN-β) decreases the number of...     

Interleukin-1β and receptor antagonist (IL-1Ra) gene polymorphisms and the prediction of the risk of end-stage renal disease

Abstract

Cytokines play an important role in the pathogenesis of kidney disease and its progression to end-stage renal disease (ESRD). Inflammation is regulated by the genes of the interleukin 1 (IL-1) gene cluster. Therefore, it was hypothesized that a polymorphism in this gene cluster may be associated with the risk of ESRD. Polymorphisms in the IL-1 gene cluster were examined in a cohort of 222 ESRD patients and 206 controls of similar ethnicity. These individuals were genotyped for IL-1 β (promoter –511 and exon-5 +3953) genes and a variable number of tandem repeats (VNTR) in the IL-1 receptor antagonist gene (IL-1Ra). There was significant difference in genotype frequencies between ESRD patients and control group for IL-1β (promoter region and exon-5) and IL-1Ra gene polymorphism (p<0.001, 0.006 and?<?0.001, respectively). A significant difference was observed in IL-1Ra for 1/1 (410/410) and 1/2 (410/240) genotypes, and the risk for ESRD was higher in those carrying the 1/1 genotype (p=0.014, OR?=?1.692, and p<0.001, OR?=?0.163). Also identified was a novel, rare allele of a single copy of 86 bp in ESRD patients as compared with the controls. The haplotype ‘T-E2-1’ frequency distribution between patients and controls revealed greater than threefold risk (p=0.001, OR?=?3.572, 95% CI?=?1.589–8.032). Genetic linkage between the IL-1β promoter region and exon-5 and between the IL-1β promoter and IL-1Ra of IL-1 gene demonstrated a strong association among the variants in controls (D′?=?0.42, p<0.001, and D′?=?0.39, p=0.001). Thus, the three polymorphisms within the IL-1 cluster are associated with ESRD. This finding is perhaps one of the strongest associations between genotype and ESRD reported, and it suggests that the IL-1 gene cluster affects the risk of development of ESRD.     

Association of a variant in exon 31 of the sulfonylurea receptor 1 (SUR1) gene with type 2 diabetes mellitus in French Caucasians

The sulfonylurea receptor (SUR1) of the pancreatic beta-cell ATP-sensitive potassium channel plays a key role in glucose-induced insulin secretion. The A-allele of a single nucleotide polymorphism (SNP) in exon 31 of the SUR1 gene (AGG-->AGA; Arg1273Arg) has previously been shown to be associated with hyperinsulinemia in nondiabetic Mexican-American subjects. Here, we have investigated the association of this SNP with type 2 diabetes mellitus (T2DM) in French Caucasian subjects. We have observed an increased frequency of the A allele (37.1% vs 27.6%, P=0.0048; odds ratio 1.54), of the AA genotype (15.7% vs 9.8%; P=0.025), and of the combined AA/AG genotypes (58.5% vs 45.5%, P=0.0098; odds ratio 1.69) in patients compared with controls. This association is stronger in the subgroup of patients with age of diagnosis of diabetes equal to or less than 45 years: A allele 43.2% (P=0.0003 compared with controls; odds ratio 1.99), AA genotype 21.4% (P=0.0032), and combined AA/AG genotypes 65.1% (P=0.0022; odds ratio 2.23). Unexpectedly, the G allele is strongly associated with arterial hypertension in obese diabetic subjects (GG vs AA odds ratio 19.97). In conclusion, we have observed an association of an SNP in exon 31 of the SUR1 gene with T2DM. These data reinforce the hypothesis that insulin secretion defects in T2DM might be at least partially related to allelic variations in the SUR1 gene.     

Identification of missense, nonsense, and deletion mutations in the GRHPR gene in patients with primary hyperoxaluria type II (PH2)

Primary hyperoxaluria type II (PH2) is a rare disease characterized by the absence of an enzyme with glyoxylate reductase, hydroxypyruvate reductase, and D-glycerate dehydrogenase activities. The gene encoding this enzyme (GRHPR) has been characterized, and a single mutation has been detected in four PH2 patients. In this report, we have identified five novel mutations. One nonsense mutation (C295T) results in a premature stop codon at codon 99. A 4-bp deletion mutation has been found in the 5' consensus splice site of intron D, resulting in a predicted splicing error. Three missense mutations have been detected, including a missense transversion (T965G) in exon 9 (Met322Arg), a missense transition (G494A) in the putative co-factor binding site in exon 6 (Gly165Asp), and a substitution of an adenosine for a guanine in the 3' splice site of intron G. The functional consequences of the missense transversion and transition mutations have been investigated by transfection of cDNA encoding the mutated protein into COS cells. Cells transfected with either mutant construct have no enzymatic activity, a finding that is not significantly different from the control (empty) vector (P<0.05). These results further confirm that mutations in the GRHPR gene form the genetic basis of PH2. Ten of the 11 patients that we have genotyped are homozygous for one of the six mutations identified to date. Because of this high proportion of homozygotes, we have used microsatellite markers in close linkage with the GRHPR gene to investigate the possibility that the patients are the offspring of related individuals. Our data suggest that two thirds of our patients are the offspring of either closely or distantly related persons. Furthermore, genotyping has revealed the possible presence of a founder effect for the two most common mutations and the location of the gene near the marker D9S1874.     

Altered islet composition and disproportionate loss of large islets in patients with type 2 diabetes

Human islets exhibit distinct islet architecture with intermingled alpha- and beta-cells particularly in large islets. In this study, we quantitatively examined pathological changes of the pancreas in patients with type 2 diabetes (T2D). Specifically, we tested a hypothesis that changes in endocrine cell mass and composition are islet-size dependent. A large-scale analysis of cadaveric pancreatic sections from T2D patients (n = 12) and non-diabetic subjects (n = 14) was carried out combined with semi-automated analysis to quantify changes in islet architecture. The method provided the representative islet distribution in the whole pancreas section that allowed us to examine details of endocrine cell composition in individual islets. We observed a preferential loss of large islets (>60 µm in diameter) in T2D patients compared to non-diabetic subjects. Analysis of islet cell composition revealed that the beta-cell fraction in large islets was decreased in T2D patients. This change was accompanied by a reciprocal increase in alpha-cell fraction, however total alpha-cell area was decreased along with beta-cells in T2D. Delta-cell fraction and area remained unchanged. The computer-assisted quantification of morphological changes in islet structure minimizes sampling bias. Significant beta-cell loss was observed in large islets in T2D, in which alpha-cell ratio reciprocally increased. However, there was no alpha-cell expansion and the total alpha-cell area was also decreased. Changes in islet architecture were marked in large islets. Our method is widely applicable to various specimens using standard immunohistochemical analysis that may be particularly useful to study large animals including humans where large organ size precludes manual quantitation of organ morphology.     

Mutations in the 4-hydroxyphenylpyruvate dioxygenase gene (HPD) in patients with tyrosinemia type III

Tyrosinemia type III (OMIM 276710) is an autosomal recessive disorder caused by the deficiency of 4-hydroxyphenylpyruvate dioxygenase (HPD), the second enzyme in the tyrosine catabolic pathway. The enzyme deficiency results in an accumulation and increased excretion of tyrosine and phenolic metabolites. Only a few cases with the disorder have been described, and the clinical spectrum of the disorder is unknown. Reported patients have presented with mental retardation or neurological symptoms or have been picked up by neonatal screening. We have identified four presumed pathogenic mutations (two missense and two nonsense mutations) in the HPD gene in three unrelated families encompassing four homozygous individuals and one compound heterozygous individual with tyrosinemia type III. Furthermore, a number of polymorphic mutations have been identified in the HPD gene. No correlation of the severity of the mutation and enzyme deficiency and mental function has been found; neither do the recorded tyrosine levels correlate with the clinical phenotype.