Association of CYP1B1 germ line mutations with hepatocyte nuclear factor 1alpha-mutated hepatocellular adenoma.

Biallelic somatic mutations of TCF1 coding for hepatocyte nuclear factor 1alpha (HNF1alpha) are found in 50% of the hepatocellular adenoma (HCA) cases usually associated with oral contraception. In rare cases, HNF1alpha germ line mutations could also predispose to familial adenomatosis. In order to identify new genetic factors predisposing to HNF1alpha-mutated HCA, we searched for mutations in genes involved in the metabolism of estrogen. For 10 genes (CYP1A1, CYP1A2, CYP3A4, CYP3A5, COMT, UGT2B7, NQO1, GSTM1, GSTP1, and GSTT1), we did not find mutations nor differences in the allele distribution among 32 women presenting HNF1alpha-mutated adenomas compared with 58 controls. In contrast, we identified a CYP1B1 germ line heterozygous mutation in 4 of 32 women presenting HNF1alpha-mutated adenomas compared with none in 58 controls. We confirmed these results with the identification of four additional CYP1B1 mutations in a second series of 26 cases. No mutations were found in the control group, which was extended to 98 individuals, and only a known rare genetic variant was observed in two controls (P = 0.0003). We did an ethoxyresorufin O-deethylase assay to evaluate the functional consequence of the CYP1B1 mutations. We found reduced enzymatic activity in each CYP1B1 variant. In addition, an E229K CYP1B1 mutation was found in a woman with a germ line HNF1alpha mutation in a familial adenomatosis context. In this large family, all three patients with adenomatosis bore both HNF1 and CYP1B1 germ line mutations. In conclusion, our data suggested that CYP1B1 germ line-inactivating mutations might increase the incidence of HCA in women with HNF1alpha mutations.

Plasma and intraprostatic concentrations of ertapenem following preoperative single dose administration: a single-centre prospective experience and clinical implications-the ERTAPRO study.

The incidence of urinary tract infections caused by extended-spectrum ß-lactamase (ESBL)-producing pathogens is increasing. These infections are associated with a long hospital stay in patients undergoing urological procedures. We aimed to demonstrate that significant intraprostatic diffusion of ertapenem is achieved after a single preoperative administration. A referred sample of 19 patients requiring surgery for benign prostatic hyperplasia was prospectively included. Patients received a 1 g intravenous (i.v.) dose of ertapenem 1 h (n = 10, group A) or 12 h (n = 9, group B) before blood and prostatic samples were collected. Plasma and intraprostatic concentrations of ertapenem were measured using LC-MS/MS. Intraprostatic concentrations were considered satisfactory when higher than the MIC90 value of urinary-targeted pathogens perioperatively and for 40% of the dosing interval. The Wilcoxon test and a pharmacokinetic predictive model were used. Median plasma concentrations of ertapenem were 144.3 mg/L (95% CI 126.5-157.9) in group A and 30.7 mg/L (95% CI 22.9-36.4) in group B (P < 0.001); median intraprostatic concentrations were 16.6 mg/L (95% CI 13.3-31.4 mg/L) and 4.2 mg/L (95% CI 3.1-4.9 mg/L), respectively (P < 0.001), which were above the MIC90 values of bacteria, including ESBL-producers, during surgery and for 40% of the dosing interval. The plasma-to-prostate concentration ratio was not significantly different between groups (P = 0.97). Single-dose i.v. ertapenem reached satisfactory intraprostatic concentrations, suggesting that it could be a relevant prophylactic strategy for carriers of ESBL-producing bacteria undergoing prostatic procedures, which needs to be confirmed by further prospective trials.

A European study of HLA-B in Stevens-Johnson syndrome and toxic epidermal necrolysis related to five high-risk drugs.

BACKGROUND: Stevens-Johnson syndrome (SJS) and its severe form, toxic epidermal necrolysis (TEN), are rare but life-threatening cutaneous adverse reactions to drugs, especially to allopurinol, carbamazepine, lamotrigine, phenobarbital, phenytoine, sulfamethoxazole, oxicam and nevirapine. Recently, a strong association between carbamazepine and allopurinol induced SJS or TEN has been described with respectively, HLA-B*1502 and HLA-B*5801 in a Han Chinese population from Taiwan and other Asian countries. OBJECTIVE: The objective is to further investigate the relationship between SJS/TEN and HLA-B in a large number of patients in a European population. METHODS: HLA-B genotyping was performed on 150 patients included in a European study (RegiSCAR) of SJS and TEN. We focused on patients related to 'high-risk' drugs including: 31 cases related to allopurinol, 28 to sulfamethoxazole, 19 to lamotrigine and 14 to oxicam. RESULTS: Sixty-one percent of 31 allopurinol-induced SJS/TEN patients carried the HLA-B*5801 allele and the figure was 55% for 27 patients of European ancestry [odds ratio=80 (34-187)], (P<10(-6)) as previously observed in Han Chinese. For other drugs, two rare alleles showed a weaker association with SJS/TEN in a limited number of patients: B*38 for sulfamethoxazole or lamotrigine-related patients, and B*73 for oxicam. CONCLUSION: At variance with prior results in Asia, this study shows that even when HLA-B alleles behave as strong risk factors, as for allopurinol, they are neither sufficient nor necessary to explain the disease. Further investigations are necessary to delineate the exact role of the HLA region in SJS/TEN, and to look for other associations in other regions of the genome.

Hepatocellular adenoma displaying a HNF1alpha inactivation in a patient with familial adenomatous polyposis coli.

Patients with familial adenomatous polyposis coli (FAP) may rarely develop hepatocellular adenoma. Here we report the case of a 37-year-old FAP woman presenting a hepatocellular adenoma after oestroprogestative oral contraception use. In this steatotic adenoma, we identified an inactivating biallelic mutation of HNF1alpha. In addition to the known germline APC mutation Q1062fs, we did not find an inactivation of the second APC allele nor an activation of the beta-catenin target genes GLUL and GPR49. Our findings contrast with two hepatocellular adenoma cases related to FAP, for which a biallelic inactivation of the APC gene was previously described. Altogether, these results suggest that benign hepatocellular carcinogenesis may be dependent on or independent of the Wnt/beta-catenin pathway in patients with FAP.

Genetic and clinical implications of the Val617Phe JAK2 mutation in 72 families with myeloproliferative disorders.

To study the prevalence of the Val617Phe JAK2 mutation in familial cases of myeloproliferative disorder (MPD) and its possible implication as a predisposing genetic factor, we analyzed 72 families including 174 patients (81 polycythemia vera [PV], 68 essential thrombocythemia [ET], 11 myelofibrosis with myeloid metaplasia [MMM], 12 chronic myeloid leukemia), 1 systemic mastocytosis, and 1 chronic myelomonocytic leukemia (CMML). The JAK2 mutation was found in three quarters of patients with PV and MMM and in half of patients with ET. Among 46 families with at least 2 cases of PV, ET, or MMM, the JAK2 mutation was absent in 6 families, heterogeneously distributed in 18, and present in all MPD patients in 22. Among these 22 families, the absence of the JAK2 mutation both in purified T and B cells in 13 unrelated patients and the observation of variable ratios of the JAK2 mutant allele in patient leucocytes indicated that the Val617Phe JAK2 mutation was acquired in familial MPDs. The JAK2 mutation was present in natural killer cells in two thirds of tested patients (27 of 40), suggesting its occurrence in a multipotent hematopoietic progenitor cell. The analysis of the hematologic profile showed that the homozygous JAK2 mutation confers a proliferative advantage and is associated with the progression of the hematologic disease.

Association between tumor necrosis factor receptor II and familial, but not sporadic, rheumatoid arthritis: evidence for genetic heterogeneity.

OBJECTIVE: Tumor necrosis factor alpha (TNFalpha) binds the receptors TNFRI and TNFRII. Results of genome scans have suggested that TNFR2 is a candidate rheumatoid arthritis (RA) locus. A case-control study in a UK Caucasian population has shown an association between a TNFR2 genotype (196R/R in exon 6) and familial, but not sporadic, RA. The present study was undertaken to test this association in the French Caucasian population. METHODS: To test for an association in sporadic RA, 100 families were genotyped for the 196M/R polymorphism and analyzed using the transmission disequilibrium test and haplotype relative risk. To test for an association in familial RA, RA index cases from 100 affected sibpair (ASP) families were genotyped for 196M/R. Linkage analysis was performed with 3 TNFR2 microsatellite markers. RESULTS: The TNFR2 196R/R genotype was not associated with sporadic RA (odds ratio [OR] 0.59, P = 0.72), but was associated with familial RA (OR 4.0, P = 0.026). The association was most marked in the context of TNFR2 "twin-like" RA sibs (affected sibs sharing both TNFR2 haplotypes) (OR 9.2, P = 0.0017). Linkage analysis results were consistent with the association; most of the TNFR2 linkage evidence was found in the subgroup of families with 196R/R ASP index cases. CONCLUSION: This study is the first to replicate evidence of the involvement of TNFR2 in RA genetic heterogeneity. Our data refine the initial hypothesis, to suggest that a TNFR2 recessive factor, in linkage disequilibrium with the 196R allele, plays a major role in a subset of families with multiple cases of RA.

Significant linkage to spondyloarthropathy on 9q31-34.

Spondyloarthropathy (SpA) is a frequent rheumatologic disorder with a prevalence of 0.3% in Caucasian populations from western Europe. It commonly presents as chronic axial and/or peripheral arthritis with potential disabling outcome. SpA is also variably associated with extra-articular manifestations. The pathogenesis of SpA is considered as complex, with a strong genetic component. Human leukocyte antigen B27 has been identified as a predisposing factor for SpA, but family and twin studies suggest that additional genetic risk factors exist outside the major histocompatibility complex (MHC). To map SpA susceptibility loci, 120 multiplex SpA families were included in a genome-wide scan. Linkage analyses performed on the first 65 families allowed us to identify four candidate non-MHC regions on chromosomes 5q, 9q, 13q and 17q, which were further explored in the remaining 55 multiplex families (extension study). Non-parametric multipoint linkage analyses of the whole data set yielded evidence of significant linkage to 9q31-34, in the vicinity of marker D9S1776 (NPL=4.87, LOD=5.15, P=0.00002). This result provides evidence for the presence of a non-MHC susceptibility locus for SpA mapping to 9q31-34.

A 3.9-centimorgan-resolution human single-nucleotide polymorphism linkage map and screening set.

Recent advances in technologies for high-throughout single-nucleotide polymorphism (SNP)-based genotyping have improved efficiency and cost so that it is now becoming reasonable to consider the use of SNPs for genomewide linkage analysis. However, a suitable screening set of SNPs and a corresponding linkage map have yet to be described. The SNP maps described here fill this void and provide a resource for fast genome scanning for disease genes. We have evaluated 6,297 SNPs in a diversity panel composed of European Americans, African Americans, and Asians. The markers were assessed for assay robustness, suitable allele frequencies, and informativeness of multi-SNP clusters. Individuals from 56 Centre d'Etude du Polymorphisme Humain pedigrees, with >770 potentially informative meioses altogether, were genotyped with a subset of 2,988 SNPs, for map construction. Extensive genotyping-error analysis was performed, and the resulting SNP linkage map has an average map resolution of 3.9 cM, with map positions containing either a single SNP or several tightly linked SNPs. The order of markers on this map compares favorably with several other linkage and physical maps. We compared map distances between the SNP linkage map and the interpolated SNP linkage map constructed by the deCode Genetics group. We also evaluated cM/Mb distance ratios in females and males, along each chromosome, showing broadly defined regions of increased and decreased rates of recombination. Evaluations indicate that this SNP screening set is more informative than the Marshfield Clinic's commonly used microsatellite-based screening set.