Increased carotid plaque burden in men with the fibrillin-1 2/3 genotype.

Fibrillin-1 (FBN1) is an important constituent of the vascular wall and earlier studies have indicated an effect of the FBN1 2/3 genotype on blood pressure as well as aortic stiffness in men. The aim of the present study was to determine whether the FBN1 2/3 genotype was associated with the presence of carotid plaque and incident cardiovascular morbidity and mortality in middle-aged subjects. The FBN1 genotype was characterized in 5765 subjects (2424 men, 3341 women; age 45-69 years) recruited from the Malmö Diet and Cancer Study Cardiovascular Cohort, Sweden.

t(14;18) Translocation: A predictive blood biomarker for follicular lymphoma.

Purpose: The (14;18) translocation constitutes both a genetic hallmark and critical early event in the natural history of follicular lymphoma (FL). However, t(14;18) is also detectable in the blood of otherwise healthy persons, and its relationship with progression to disease remains unclear. Here we sought to determine whether t(14;18)-positive cells in healthy individuals represent tumor precursors and whether their detection could be used as an early predictor for FL.

HLA DR-DQ genotyping by capillary electrophoresis for risk assessment for celiac disease.

The risk for celiac disease (CD) is clearly related to specific HLA DQA1 and DQB1 alleles, but HLA -typing is often considered too costly for frequent use.Here we present a method using sequence-specific primed PCR (PCR-SSP) for HLA-DR-DQ genotyping optimized for capillary electrophoresis on Applied Biosystems 3130xl Genetic Analyzer. Requiring a total of three PCR reactions and a single electrophoretic step, this method reduces the reagent expenses and technical time for directed HLA typing to distinguish risk alleles for CD, with a sufficient throughput for large-scale screening projects.

Semi-automated quantification of methylmalonic acid in human serum by LC-MS/MS.

Background: Methylmalonic acid (MMA), a sensitive biomarker of functional vitamin B12 deficiency, is commonly determined by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using manual extraction and derivatization of MMA to reduce polarity prior to separation.

Methods: In the present study we introduce a semi-automated extraction on a strong anion exchanger, HPLC separation on a BEH-amide column to separate serum MMA from its abundant isoform, succinic acid, followed by MS/MS detection and quantification.

Results: The extraction of MMA plus internal standard provides full recovery and the method is linear between 0.

Genetic predisposition, parity, age at first childbirth and risk for breast cancer.

Background: Recent studies have identified several single-nucleotide polymorphisms (SNPs) associated with the risk of breast cancer and parity and age at first childbirth are well established and important risk factors for breast cancer. The aim of the present study was to examine the interaction between these environmental factors and genetic variants on breast cancer risk.

Methods: The Malmö Diet and Cancer Study (MDCS) included 17 035 female participants, from which 728 incident breast cancer cases were matched to 1448 controls.

Design of recombinant antibody microarrays for urinary proteomics.

Purpose: Urinary proteomics has become a key discipline within clinical proteomics for noninvasive diagnosis and monitoring of disease, and biomarker discovery. In order to decipher complex proteomes, high demands will, however, be placed upon the methodology applied. The purpose of this study was to develop a recombinant antibody microarray platform for urinary proteomics.

Interactive effect of genetic susceptibility with height, body mass index, and hormone replacement therapy on the risk of breast cancer.

Background: Breast cancer today has many established risk factors, both genetic and environmental, but these risk factors by themselves explain only part of the total cancer incidence. We have investigated potential interactions between certain known genetic and phenotypic risk factors, specifically nine single nucleotide polymorphisms (SNPs) and height, body mass index (BMI) and hormone replacement therapy (HRT).

Methods: We analyzed samples from three different study populations: two prospectively followed Swedish cohorts and one Icelandic case-control study.

A common missense variant in the ATP receptor P2X7 is associated with reduced risk of cardiovascular events.

Background And Purpose: Extracellular adenosine triphosphate (ATP) regulates inflammatory cells by activation of the P2X(7) receptor. We hypothesized that polymorphisms in P2RX7 influence the risk of ischemic heart disease (IHD), ischemic stroke (IS) and cardiovascular risk factors and tested this hypothesis using genetic association studies.

Methods: Two loss-of-function SNPs in P2RX7 were genotyped in 1244 IHD cases and 2488 controls as well as 5969 individuals with cardiovascular risk factors.

Multiple loci in the HLA complex are associated with Addison's disease.

Context: A strong association between autoimmune Addison's disease (AAD) and major histocompatibility complex class II-encoded HLA-DRB1-DQA1-DQB1 haplotypes is well known. Recent evidence from other autoimmune diseases has suggested that class I-encoded HLA-A and HLA-B gene variants confer HLA-DRB1-DQA1-DQB1-independent effects on disease.

Objective: We aimed to explore AAD predisposing effects of HLA-A and -B and further investigate the role of MICA and HLA-DRB1-DQA1-DQB1 in a much larger material than has previously been studied.

Single nucleotide polymorphisms in the 20q13 amplicon genes in relation to breast cancer risk and clinical outcome.

The 20q13 region is frequently amplified/overexpressed in breast tumours. However, the nature of this amplification/overexpression is unknown. Here, we investigated genetic variation in five 20q13 amplicon genes (MYBL2, AURKA, ZNF217, STK4 and PTPN1) and its impact on breast cancer (BC) susceptibility and clinical outcome.

Genetic variants in serum and glucocortocoid regulated kinase 1, a regulator of the epithelial sodium channel, are associated with ischaemic stroke.

Objective: Serum and glucocorticoid regulated kinase 1 (SGK1) expression is increased by aldosterone and is a key regulator of the amiloride-sensitive sodium channel (ENaC) in the distal nephron. We have previously shown that two SNPs in SGK1 (rs1057293 and rs1743966) are associated with blood pressure variation and blood pressure progression in the general population. Therefore, we tested the association of these variants with ischaemic stroke.

A new PCR-SSP method for HLA DR-DQ risk assessment for celiac disease.

Background: Susceptibility to celiac disease is essentially restricted to carriers of specific HLA DQA1 and DQB1 alleles. We have developed a semi-automated sequence specific primer (SSP) PCR method for clinical HLA typing and compared the test results with those from a commercial method.

Methods: Primers for each DQA1 and DQB1 allele group were included in our PCR-SSP reaction to allow differentiation of homozygous from heterozygous carriers of risk alleles.

A candidate CpG SNP approach identifies a breast cancer associated ESR1-SNP.

Altered DNA methylation is often seen in malignant cells, potentially contributing to carcinogenesis by suppressing gene expression. We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1). Genome-wide searches for genetic risk factors for breast cancers have in general not investigated these SNPs, because of low minor allele frequency or weak haplotype associations.

Extraction, quantitation, and evaluation of function DNA from various sample types.

Two vital pre-requisites for genetic epidemiology have been fullfiled during the past decade and have led to a virtual explosion of knowledge concerning disease risks. Reliable databases over genetic variation derived from, e.g.

HLA class I and genetic susceptibility to type 1 diabetes: results from the Type 1 Diabetes Genetics Consortium.

Objective: We report here genotyping data and type 1 diabetes association analyses for HLA class I loci (A, B, and C) on 1,753 multiplex pedigrees from the Type 1 Diabetes Genetics Consortium (T1DGC), a large international collaborative study.

Research Design And Methods: Complete eight-locus HLA genotyping data were generated. Expected patient class I (HLA-A, -B, and -C) allele frequencies were calculated, based on linkage disequilibrium (LD) patterns with observed HLA class II DRB1-DQA1-DQB1 haplotype frequencies.

HLA genotyping in the international Type 1 Diabetes Genetics Consortium.

Background: Although human leukocyte antigen (HLA) DQ and DR loci appear to confer the strongest genetic risk for type 1 diabetes, more detailed information is required for other loci within the HLA region to understand causality and stratify additional risk factors. The Type 1 Diabetes Genetics Consortium (T1DGC) study design included high-resolution genotyping of HLA-A, B, C, DRB1, DQ, and DP loci in all affected sibling pair and trio families, and cases and controls, recruited from four networks worldwide, for analysis with clinical phenotypes and immunological markers.

Purpose: In this article, we present the operational strategy of training, classification, reporting, and quality control of HLA genotyping in four laboratories on three continents over nearly 5 years.

Plasma folate concentrations are positively associated with risk of estrogen receptor beta negative breast cancer in a Swedish nested case control study.

Folate's role in breast cancer development is controversial. Not only estrogen receptor (ER) alpha status, but also ERbeta status of tumors may have confounded results from previous epidemiological studies. We aimed to examine associations between plasma folate concentration and postmenopausal breast cancer defined by ER status.

HLA DPA1, DPB1 alleles and haplotypes contribute to the risk associated with type 1 diabetes: analysis of the type 1 diabetes genetics consortium families.

Objective: To determine the relative risk associated with DPA1 and DPB1 alleles and haplotypes in type 1 diabetes.

Research Design And Methods: The frequency of DPA1 and DPB1 alleles and haplotypes in type 1 diabetic patients was compared to the family based control frequency in 1,771 families directly and conditional on HLA (B)-DRB1-DQA1-DQB1 linkage disequilibrium. A relative predispositional analysis (RPA) was performed in the presence or absence of the primary HLA DR-DQ associations and the contribution of DP haplotype to individual DR-DQ haplotype risks examined.

Common genetic variants on chromosome 9p21 confers risk of ischemic stroke: a large-scale genetic association study.

Background: Epidemiological studies indicate a genetic contribution to ischemic stroke risk, but specific genetic variants remain unknown, with the exception of a few rare variants. Recent genome-wide association studies identified and replicated common genetic variants on chromosome 9p21 to confer risk of coronary heart disease. We examined whether these variants are associated with ischemic stroke.

Polymorphism in the oxytocin promoter region in patients with lactase non-persistence is not related to symptoms.

Background: Oxytocin and the oxytocin receptor have been demonstrated in the gastrointestinal (GI) tract and have been shown to exert physiological effects on gut motility. The role for oxytocin in the pathophysiology of GI complaints is unknown. The aim of this study was to examine genetic variations or polymorphism of oxytocin (OXT) and its receptor (OXTR) genes in patients with GI complaints without visible organic abnormalities.

A new automated human leukocyte antigen genotyping strategy to identify DR-DQ risk alleles for celiac disease and type 1 diabetes mellitus.

Background: The risk for type 1 diabetes mellitus (T1DM) and celiac disease (CD) is related to human leukocyte antigen (HLA) DQA1, DQB1 and DRB1 loci. Unfortunately, HLA typing has been too difficult and costly for frequent use. Automated genotyping focused on risk alleles could provide access to HLA typing in diagnostic evaluations, epidemiological screening and contribute to preventive strategies.

Clinical, immunological, and genetic features of autoimmune primary adrenal insufficiency: observations from a Norwegian registry.

Objective: Primary adrenal insufficiency [Addison's disease (AD)] is rare, and systematic studies are few, mostly conducted on small patient samples. We aimed to determine the clinical, immunological, and genetic features of a national registry-based cohort.

Design: Patients with AD identified through a nationwide search of diagnosis registries were invited to participate in a survey of clinical features, health-related quality of life (HRQoL), autoantibody assays, and human leukocyte antigen (HLA) class II typing.

Increased breast cancer risk at high plasma folate concentrations among women with the MTHFR 677T allele.

Background: Folate is involved in DNA synthesis and methylation and may thereby influence carcinogenesis.

Objectives: We examined plasma folate (P-folate) concentration in relation to genotypes of the folate-metabolizing enzyme methylenetetrahydrofolate reductase [MTHFR 677C-->T (rs1801133) and 1298A-->C (rs1801131)]. We also explored whether P-folate was associated with risk of postmenopausal breast cancer overall and in subgroups with genetic variants of the MTHFR single nucleotide polymorphisms (SNPs).

Folate intake, methylenetetrahydrofolate reductase polymorphisms, and breast cancer risk in women from the Malmö Diet and Cancer cohort.

Background: Single nucleotide polymorphisms (SNP) of the folate-metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR) may modify associations between folate intake and breast cancer. We examined if the association between tertiles of dietary folate equivalents (DFE) and breast cancer was different in subgroups according to genotypes of the MTHFR 677 C>T (rs1801133) and 1298A>C (rs1801131) SNPs and if the polymorphisms per se were associated with breast cancer.

Methods: This nested case-control study included 544 incident cases with invasive breast cancer and 1,088 controls matched on age and blood sampling date from the population-based Malmö Diet and Cancer cohort.