The UGT1A1*28 gene variant predicts long-term mortality in patients undergoing coronary angiography.

BACKGROUND: Uridine diphosphate glycosyltransferases 1A1 (UGT1A1) plays an essential role in detoxification and excretion of several endogenous and exogenous compounds. A functional polymorphism in the promoter of the UGT1A1 gene (TA repeat insertion, UGT1A1*28, rs3064744) has been associated with reduced UGT1A1 enzyme activity. The purpose of the present study was to investigate the role of UGT1A1 genotypes in mortality. METHODS: UGT1A1 genotypes as well as baseline plasma bilirubin levels were analyzed in participants of the Ludwigshafen Risk and Cardiovascular Health study (n=3316). UGT1A1*28 genotypes were determined on an ABI PRISM 3730 genetic analyzer. RESULTS: As expected, UGT1A1 genotypes were associated with baseline bilirubin levels (*1/*1 genotype: 9.1±4.6 µmol/L; *1/*28 genotype: 10.8±5.3; *28/*28: 16.9±9.2; p<0.001). During a median follow-up of 10.4 years, 995 subjects (30.0%) died. In a multivariate regression analysis adjusting for age, sex, smoking, type 2 diabetes, dyslipidemia, alanine aminotransferase (ALT) levels and bilirubin levels, the UGT1A1*28 variant predicted lower overall mortality (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.78-0.95; p=0.003). Contrary to expected, higher baseline bilirubin levels predicted increased mortality (HR, 1.014; 95% CI, 1.002-1.025; p=0.019). CONCLUSIONS: The UGT1A1*28 gene variant is associated with lower mortality rates. The protective effect of the UGT1A1*28 variant likely includes mechanism other than bilirubin metabolism.

Higher incidence of the SNP Met 788 Ile in the coding region of A20 in diffuse large B cell lymphomas.

Genetic alterations causing constitutive activation of the nuclear factor kappa B (NF-κB) signaling pathway has been associated with the development of lymphomas. A20 (TNFAIP3) is a key regulator of NF-κB signaling. Its suppressor functions are often inactivated by deletions and/or mutations in various hematologic malignancies. Since we recently found the rs143002189 polymorphism in the A20 loci in our multiple myeloma samples, we further investigated this polymorphism in different lymphoid neoplasias. For this purpose, we tested 479 cases of the most common B cell malignancies for the presence of the rs143002189 polymorphism. We found a significant higher occurrence of the rs143002189 polymorphism in diffuse large B cell lymphoma (DLBCL) compared to non-neoplastic controls and other types of B cell malignancies. Furthermore, structure analyses of the mutated A20 protein led to the assumption that the new steric interaction within the protein is responsible for a reduced or inactivated A20 protein. Our data indicates that in a significant fraction of patients, rs143002189 might contribute to the development of DLBCL.

A novel exonuclease (TaqMan) assay for rapid haptoglobin genotyping.

BACKGROUND: Haptoglobin is an acute-phase binding protein that scavenges free hemoglobin. The human haptoglobin gene (HP) is polymorphic with two main alleles, haptoglobin allele 1 (Hp1) and haptoglobin allele 2 (Hp2). The smaller Hp1 allele features no duplication and consists of four exons, whereas the larger Hp2 allele, containing a 1.7 kb duplication, consists of six exons, with the fifth and sixth being highly homologous to exons 3 and 4 of Hp1. METHODS: We designed an exonuclease (TaqMan) assay targeting single nucleotide differences between the homologous regions of Hp1 and Hp2. The assay contained one probe specifically binding to a site in intron 4 of Hp2, and another probe binding equally to intron 4 of Hp1 and intron 6 of Hp2. RESULTS: Measurement of post-PCR fluorescence allowed unambiguous discrimination of HP genotypes. Comparison with genotypes obtained by a method based upon allele-specific primers yielded fully corresponding results. CONCLUSIONS: The new HP genotyping method is fast, reliable, does not require real-time instruments and may be especially useful for high-throughput genotyping.

Association of polymorphisms in the chemokine receptor CX3CR1 gene with coronary artery disease.

Two chemokine receptor CX3CR1 gene variants, V249I and T280M, have been implicated in coronary artery diseases (CAD). Currently no consistent effect has been revealed and their role in cardiovascular disease is still conflicting. In the present study the association of CX3CR1 genotypes with CAD and myocardial infarction (MI) was investigated in the Ludwigshafen Risk and Cardiovascular Health (LURIC) cohort, including 3316 individuals in whom cardiovascular disease angiographically has been defined or ruled out. Similarly to previous studies, the alleles I249 and M280 were in strong linkage disequilibrium and formed an I(249)M(280) haplotype. However, there was no relationship between CX3CR1 genotypes or corresponding haplotypes and the prevalence of CAD or MI. Adjusted for classical risk factors (age, sex, hypertension, dyslipidemia, diabetes mellitus and smoking), the odds ratio (OR) of V249I for CAD was 0.95 (95% confidence interval (CI)=0.78-1.15, p=0.61). The OR of T280M for CAD was 0.83 (95% CI=0.66-1.04, p=0.11). Furthermore, CX3CR1 variants were not associated with C-reactive protein levels, age at onset of CAD, severity of CAD and MI. In conclusion, present data of LURIC do not support the hypothesis that common variants of the CX3CR1 gene are associated with the presence of CAD or MI.

Frequent down regulation of the tumor suppressor gene a20 in multiple myeloma.

Multiple myeloma (MM) is a malignant clonal expansion of plasma cells in the bone marrow and belongs to the mature B-cell neoplams. The pathogenesis of MM is associated with constitutive NF-κB activation. However, genetic alterations causing constitutive NF-κB activation are still incompletely understood. Since A20 (TNFAIP3) is a suppressor of the NF-κB pathway and is frequently inactivated in various lymphoid malignancies, we investigated the genetic and epigenetic properties of A20 in MM. In total, of 46 patient specimens analyzed, 3 single base pair exchanges, 2 synonymous mutations and one missense mutation were detected by direct sequencing. Gene copy number analysis revealed a reduced A20 gene copy number in 8 of 45 (17.7%) patients. Furthermore, immunohistochemical staining confirmed that A20 expression correlates with the reduction of A20 gene copy number. These data suggest that A20 contributes to tumor formation in a significant fraction of myeloma patients.