Variants in the promoter region of IKBL/NFKBIL1 gene may mark susceptibility to the development of chronic Chagas` cardiomyopathy among Trypanosoma cruzi-infected individuals

Chagas` disease, caused by Trypanosoma cruzi, is an inflammatory disorder leading to chronic Chagas cardiomyopathy (CCC). Only one third of T cruzi-infected individuals progress to CCC while the others are considered asymptomatic (ASY). The human inhibitory kappa B-like gene (KBLINFKBIL1), homologous to the I kappa B family of proteins that regulate the NF kappa B family of transcription factors, is suggested as a putative inhibitor of NFKB. We investigated two functional polymorphisms, -62A/T and -262A/G, in the promoter of IKBL by PCR-RFLP analysis in 169 patients with CCC and 76 ASY. Genotype distributions for both -62A/T and -262A/G differed between the CCC and ASY (X-2 = 7.3; P = 0.025 and X-2 = 6.8; P = 0.03, respectively). Subjects, homozygous for the -62A allele, had three-fold risk of developing CCC compared with those carrying the TT genotype (P = 0.0095; Odds Ratio [OR] = 2.9; [95% CI 1.2-7.3]). Similar trend was observed for the -262A homozygotes (P = 0.005; OR = 2.7 [95% CI 1.3-6.0]. The haplotype -262A -62A was prevalent in patients with CCC (40% versus 24%; OR 2.1 [95% C1 1.4-3.3j; Pc = 0.00 14). The I kappa BL locus itself or another critical gene in this region may confer susceptibility to the development of CCC. (C) 2007 Elsevier Ltd. All rights reserved.

Assessing Interethnic Admixture Using an X-Linked Insertion-Deletion Multiplex

In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (congruent to 41%), followed by European (congruent to 32%) and African (congruent to 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations. Am. J. Hum. Biol. 21:707-709, 2009. (C) 2009 Wiley-Liss, Inc.

Translocations t(X;14)(q28;q11) and t(Y;14)(q12;q11) in T-cell prolymphocytic leukemia

P>We report a case of T-cell prolymphocytic leukemia (T-PLL) in a 41-year-old male. Classical cytogenetic, spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) studies of a blood sample obtained at diagnosis revealed the co-existence of t(X;14)(q28;q11), t(Y;14)(q12;q11) and a ring chromosome derivated from i(8)(q10). Immunophenotypic studies revealed involvement of T-cell lineage, with proliferation of CD4(-) CD8(+). The co-existence of two translocations involving both sex chromosomes in a case of T-PLL is rare. Chromosomal instability associated with the disease progression may have allowed the emergence of cell clones with translocations involving the sex chromosomes and the ring chromosome observed.

Val247Leu polymorphism of beta(2) glycoprotein 1 gene may justify the genesis of anti beta(2)GP1 antibodies and Antiphospholipid Syndrome in Multibacillary Leprosy

BACKGROUND - Multibacillary (MB) leprosy may be manifested with antiphospholipid antibodies (aPL), among which anti-beta(2)GP1 (beta(2)-glycoprotein 1). High titers of aPL are associated with APS (Antiphospholipid Syndrome), characterized by thrombosis. The mutation Val247Leu in the domain V of beta(2)GP1 exposes hidden epitopes with consequent development of anti-beta(2)GP1 antibodies. OBJECTIVE: To evaluate the Val247Leu polymorphism of beta(2)GP1 gene and its correlation with anti-beta(2)GP1 antibodies in leprosy patients. METHODS: The Val247Leu polymorphism was performed by PCR-RFLP and anti-beta(2)GP1 antibodies were measured by ELISA. RESULTS: The genotypic Val/Val was more prevalent in the leprosy group, compared to controls. Regarding the 7 MB patients with APS, four presented heterozygosis and three, Val/Val homozygosis. Although higher titrations of anti-beta(2)GP1 IgM antibodies were seen in MB leprosy group with Val/Leu and Val/Val genotypes, there was no statistical difference when compared to Leu/Leu genotype. CONCLUSION: The prevalence of Val/Val homozygosis in leprosy group can partially justify the presence of anti-beta(2)GP1 IgM antibodies in MB leprosy. The description of heterozygosis and Val/Val homozygosis in 7 patients with MB leprosy and thrombosis corroborates the implication of anomalous phenotype expression of beta(2)GP1 and development of anti-beta(2)GP1 antibodies, with consequent thrombosis and APS.

Differential gene expression of peripheral blood mononuclear cells from rheumatoid arthritis patients may discriminate immunogenetic, pathogenic and treatment features

This study aimed to evaluate the association between the differential gene expression profiling of peripheral blood mononuclear cells of rheumatoid arthritis patients with their immunogenetic (human leucocyte antigen shared-epitope, HLA-SE), autoimmune response [anti-cyclic citrullinated peptide (CCP) antibodies], disease activity score (DAS-28) and treatment (disease-modifying antirheumatic drugs and tumour necrosis factor blocker) features. Total RNA samples were copied into Cy3-labelled complementary DNA probes, hybridized onto a glass slide microarray containing 4500 human IMAGE complementary DNA target sequences. The Cy3-monocolour microarray images from patients were quantified and normalized. Analysis of the data using the significance analysis of microarrays algorithm together with a Venn diagram allowed the identification of shared and of exclusively modulated genes, according to patient features. Thirteen genes were exclusively associated with the presence of HLA-SE alleles, whose major biological function was related to signal transduction, phosphorylation and apoptosis. Ninety-one genes were associated with disease activity, being involved in signal transduction, apoptosis, response to stress and DNA damage. One hundred and one genes were associated with the presence of anti-CCP antibodies, being involved in signal transduction, cell proliferation and apoptosis. Twenty-eight genes were associated with tumour necrosis factor blocker treatment, being involved in intracellular signalling cascade, phosphorylation and protein transport. Some of these genes had been previously associated with rheumatoid arthritis pathogenesis, whereas others were unveiled for future research.

Consequences of lifetime isolated growth hormone (GH) deficiency and effects of short-term GH treatment on bone in adults with a mutation in the GHRH-receptor gene

Growth hormone (GH) influences bone mass maintenance. However, the consequences of lifetime isolated GH deficiency (IGHD) on bone are not well established. We assessed the bone status and the effect of 6 months of GH replacement in GH-naive adults with IGHD due to a homozygous mutation of the GH-releasing hormone (GHRH)-receptor gene (GHRHR). We studied 20 individuals (10 men) with IGHD at baseline, after 6 months of depot GH treatment, and 6 and 12 months after discontinuation of GH. Quantitative ultrasound (QUS) of the heel was performed and serum osteocalcin (OC) and C-terminal cross-linking telopeptide of type I collagen (ICTP) were measured. QUS was also performed at baseline and 12 months later in a group of 20 normal control individuals (CO), who did not receive GH treatment. At baseline, the IGHD group had a lower T-score on QUS than CO (-1.15 +/- 0.9 vs. -0.07 +/- 0.9, P < 0.001). GH treatment improved this parameter, with improvement persisting for 12 months post-treatment (T-score for IGHD = -0.59 +/- 0.9, P < 0.05). GH also caused an increase in serum OC (baseline vs. pGH, P < 0.001) and ICTP (baseline vs. pGH, P < 0.01). The increase in OC was more marked during treatment and its reduction was slower after GH discontinuation than in ICTP. These data suggest that lifetime severe IGHD is associated with significant reduction in QUS parameters, which are partially reversed by short-term depot GH treatment. The treatment induces a biochemical pattern of bone anabolism that persists for at least 6 months after treatment discontinuation.

An INDEL polymorphism at the X-STR GATA172D05 flanking region

A new polymorphic INDEL was detected at the X-STR GATA172D05 flanking region, which corresponds to an 18-bp deletion, 141 bp upstream the TAGA repeat motif. This INDEL was found to be polymorphic in different population samples from Native Americans, Africans, and Europeans as well as in an admixed population from the Amazonia (Bel,m). Gene diversities varied between 37.5% in Native Americans and 49.9% in Africans. Comparison between human and chimpanzee sequences showed that the ancestral state corresponds to the presence of two copies of 18 bp, detected in both species; and the mutated allele has lost one of these two copies. The simultaneous analysis of the short tandem repeat (STR) and INDEL variation showed an association between the INDEL ancestral allele with the shorter STR alleles. High diversities were found in all population groups when combining the information provided by the INDEL and STR variation. Gene diversities varied between 76.7% in Native Americans and 80.6% in both Portugal and Bel,m.

Shared and Unique Gene Expression in Systemic Lupus Erythematosus Depending on Disease Activity

Patients presenting with active Systemic lupus erythematosus (SLE) manifestations may exhibit distinct pathogenetic features in relation to inactive SLE. Also, cDNA microarrays may potentially discriminate the gene expression profile of a disease or disease variant. Therefore, we evaluated the expression profile of 4500 genes in peripheral blood lymphocytes (PBL) of SLE patients. We studied 11 patients with SLE (seven with active SLE and four with inactive SLE) and eight healthy controls. Total RNA was isolated from PBL, reverse transcribed into cDNA, and postlabeled with Cy3 fluorochrome. These probes were then hybridized to a glass slide cDNA microarray containing 4500 human IMAGE cDNA target sequences. An equimolar amount of total RNA from human cell lines served as reference. The microarray images were quantified, normalized, and analyzed using the R environment (ANOVA, significant analysis of microarrays, and cluster-tree view algorithms). Disease activity was assessed by the SLE disease activity index. Compared to the healthy controls, 104 genes in active SLE patients (80 repressed and 24 induced) and 52 genes in nonactive SLE patients (31 induced and 21 repressed) were differentially expressed. The modulation of 12 genes, either induced or repressed, was found in both disease variants; however, each disease variant had differential expression of different genes. Taken together, these results indicate that the two lupus variants studied have common and unique differentially expressed genes. Although the biological significance of the differentially expressed genes discussed above has not been completely understood, they may serve as a platform to further explore the molecular basis of immune deregulation in SLE.

Mannose binding lectin gene (MBL2) functional polymorphisms are associated with systemic lupus erythematosus in southern Brazilians

Susceptibility to systemic lupus erythematosus (SLE) has been associated with immunologic, environmental, and genetic factors. To uncover a possible association between MBL2 gene polymorphisms and SLE, we analyzed functional polymorphisms in the promoter and first exon of the MBL2 gene in 134 Brazilian SLE patients and 101 healthy controls. Genotype and allele frequencies of MBL2 A/O polymorphism were significantly different between patients and controls, and the 0 allele was associated with an increased risk of SLE. An association between low mannose binding lectin (MBL) producer combined genotypes and increased risk for SLE was also reported. Furthermore, when stratifying SLE patients according to clinical and laboratory data, an association between the A/O genotype and nephritic disorders and between the X/Y genotype and antiphospholipid syndrome was evident. Combined genotypes responsible for low MBL production were more frequently observed in SLE patients with nephritis. Our results indicate MBL2 polymorphisms as possible risk factors for SLE development and disease-related clinical manifestations. (C) 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Affected and non-affected skin fibroblasts from systemic sclerosis patients share a gene expression profile deviated from the one observed in healthy individuals

Objectives To evaluate the gene expression profile of fibroblasts from affected and non-affected skin of systemic sclerosis (SSc) patients and from controls. Materials and methods Labeled cDNA from fibroblast cultures from forearm (affected) and axillary (non-affected) skin from six diffuse SSc patients, from three normal controls, and from MOLT-4/HEp-2/normal fibroblasts (reference pool) was probed in microarrays generated with 4193 human cDNAs from the IMAGE Consortium. Microarray images were converted into numerical data and gene expression was calculated as the ratio between fibroblast cDNA (Cy5) and reference pool cDNA (Cy3) data and analyzed by R environment/Aroma, Cluster, Tree View, and SAM softwares. Differential expression was confirmed by real time PCR for a set of selected genes. Results Eighty-eight genes were up- and 241 genes down-regulated in SSc fibroblasts. Gene expression correlation was strong between affected and non-affected fibroblast samples from the same patient (r>0.8), moderate among fibroblasts from all patients (r=0.72) and among fibroblasts from all controls (r=0.70), and modest among fibroblasts from patients and controls (r=0.55). The differential expression was confirmed by real time PCR for all selected genes. Conclusions Fibroblasts from affected and non-affected skin of SSc patients shared a similar abnormal gene expression profile, suggesting that the widespread molecular disturbance in SSc fibroblasts is more sensitive than histological and clinical alterations. Novel molecular elements potentially involved in SSc pathogenesis were identified.

Effect of a thrombin receptor (protease-activated receptor 1, PAR-1) gene polymorphism in chronic hepatitis C liver fibrosis

Background and Aim: Tissue injury leads to activation of coagulation and generation of thrombin. Inhibition of thrombin receptor protease-activated receptor 1 (PAR-1) has been shown to reduce liver fibrosis in animals. This study aimed to evaluate the effect of PAR-1 gene polymorphism on rate of liver fibrosis (RF) in chronic hepatitis C. Methods: Polymorphisms studied: C > T transition 1426 bp upstream of translation start site (-1426C/T), 13 bp repeat of preceding -506 5`-CGGCCGCGGGAAG-3` sequence (-506I/D), and A > T transversion in intervening sequence (IVS) 14 bp upstream of exon-2 start site (IVS-14A/T). A total of 287 European and 90 Brazilian patients were studied. Results: 1426C/T polymorphism: There was a trend to higher RF in patients with the TT genotype (P = 0.06) and an association between genotype CC and slow fibrosis (P = 0.03) in Europeans. In males, RF was significantly higher in those with the TT genotype compared to CT (P = 0.003) and CC (P = 0.007). There was a significant association between TT and fast fibrosis (P = 0.04). This was confirmed in an independent cohort of Brazilians where RF was higher in TT than in CC (P = 0.03). Analysis of -506I/D showed no difference in RF and distribution of slow/fast fibrosis among different genotypes in both populations. Analysis of IVS-14A/T showed no difference between genotypes. Conclusion: In conclusion, these findings suggest that PAR-1 receptor polymorphisms influence the progression of liver fibrosis.

A single nucleotide deletion at the C1 inhibitor gene as the cause of hereditary angioedema: insights from a Brazilian family

Background: Hereditary angioedema is an autosomal dominant disease characterized by episodes of subcutaneous and submucosal edema. It is caused by deficiency of the C1 inhibitor protein, leading to elevated levels of bradykinin. More than 200 mutations in C1 inhibitor gene have been reported. The aim of this study was to analyze clinical features of a large family with an index case of hereditary angioedema and to determine the disease-causing mutation in this family. Methods: Family pedigree was constructed with 275 individuals distributed in five generations. One hundred and sixty-five subjects were interviewed and investigated for mutation at the C1 inhibitor gene. Subjects reporting a history of recurrent episodes of angioedema and/or abdominal pain attacks underwent evaluation for hereditary angioedema. Results: We have identified a novel mutation at the C1 inhibitor gene, c.351delC, which is a single-nucleotide deletion of a cytosine on exon 3, resulting in frameshift with premature stop codon. Sequencing analysis of the hypothetical truncated C1 inhibitor protein allowed us to conclude that, if transcription occurs, this protein has no biological activity. Twenty-eight members of the family fulfilled diagnostic criteria for hereditary angioedema and all of them presented the c.351delC mutation. Variation in clinical presentation and severity of disease was observed among these patients. One hundred and thirty-seven subjects without hereditary angioedema did not have the c.351delC mutation. Conclusion: The present study provides definitive evidence to link a novel genetic mutation to the development of hereditary angioedema in patients from a Brazilian family.

Screening of autosomal gene deletions in patients with hypogonadotropic hypogonadism using multiplex ligation-dependent probe amplification: detection of a hemizygosis for the fibroblast growth factor receptor 1

P>Objective Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin-releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons. Measurements We used the multiplex ligation-dependent probe amplification (MLPA) assay to evaluate the potential contribution of heterozygous deletions of FGFR1, GnRH1, GnRHR, GPR54 and NELF genes in the aetiology of GnRH deficiency. Patients We studied a mutation-negative cohort of 135 patients, 80 with Kallmann syndrome and 55 with normosmic hypogonadotropic hypogonadism. Results One large heterozygous deletion involving all FGFR1 exons was identified in a female patient with sporadic normosmic hypogonadotropic hypogonadism and mild dimorphisms as ogival palate and cavus foot. FGFR1 hemizygosity was confirmed by gene dosage with comparative multiplex and real-time PCRs. Conclusions FGFR1 or other autosomal gene deletion is a possible but very rare event and does not account for a significant number of sporadic or inherited cases of isolated GnRH deficiency.

Association study of an epidermal growth factor gene functional polymorphism with the risk and prognosis of gliomas in Brazil

Epidermal growth factor (EGF) plays an important role in cancer. A functional single nucleotide polymorphism (SNP) in the 5`-untranslated region of the EGF gene (+61 A>G) may influence its expression and contribute to cancer predisposition and aggressiveness. Aiming to investigate the role of EGF +61 A>G in the susceptibility to glioma and its prognosis, we performed a case-control study with 165 patients and 200 healthy controls from Brazil. Comparisons of genotype distributions and allele frequencies did not reveal any significant differences between the groups. The mean overall survival was 9.2 months for A/A, 8.2 months for A/G, and 7.7 months for GIG. When survival curves were plotted we found that the +61G allele is associated with poor overall survival (p=0.023) but not with disease-free survival (p=0.527). Our data suggest that, although there is no association between the EGF +61 A>G genotype and glioma susceptibility, this SNP is associated with shorter overall survival of glioma patients in the Brazilian population. Nevertheless, future studies utilizing a larger series are essential for a definitive conclusion. (Int J Biol Markers 2009; 24: 277-81)

DNA mismatch repair gene methylation in gastric cancer in individuals from northern Brazil

Gastric cancer is one of the most common malignancies. DNA methylation is implicated in DNA mismatch repair genes deficiency. In the present study, we evaluated the methylation status of MLH1, MSH2, MSH6 and PMS2 in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosal of gastric cancer patients from Northern Brazil. We found that none of the nonneoplastic samples showed methylation of any gene promoter and 50% of gastric, cancer samples showed at least one methylated gene promoter. Methylation frequencies of MLH1, MSH2, MSH6 and PMS2 promoter were 21.74%, 17.39%, 0% and 28.26% respectively in gastric cancer samples. MLH1 and PMS2 methylation were associated with neoplastic samples compared to nonneoplastic ones. PMS2:? methylation was associated with diffuse- and intestinal-type cancer compared with normal controls. Intestinal-type cancer showed significant association with MLH1 methylation. Diffuse-type cancer was significantly associated with MSH2 methylation. Our findings show differential gene methylation in tumoral tissue, which allows us to conclude that methylation is associated with gastric carcinogenesis. Methylation of mismatch repair genes was associated with gastric carcinogenesis and may be a helpful tool for diagnosis, prognosis and therapies. However, MSH6 does not seem to be regulated by methylation in our samples.