Single Nucleotide Polymorphisms In Codon Research Articles

Impact of Arg72Pro polymorphism in P53 gene in cancer susceptibility in Algerian population

TP53 is a tumor suppressor gene involved in the development of several types of cancer. It has been reported that single nucleotide polymorphism in codon 72 of this gene, causing substitution of a Proline for an Arginine, may increase the risk of carcinogenesis. The objective of this study was to assess the frequency of the Arg72Pro polymorphism and to look for a possible association between this polymorphism and the occurrence of cancer. Our study concerned 82 DNA samples collected from the DNA bank of the Laboratory of Biology and Molecular Genetics of the Constantine University 3, and grouped 2 populations: 41 controls and 41 patients with one of three types of cancer: breast cancer, cervical cancer and lung cancer. This polymorphism was detected with PCR / RFLP. The results obtained in our study revealed a significant difference between the two patient and control groups for the heterozygous CG genotype (OR = 0.13, P = 0.001), which makes it possible to conclude that the CG genotype constitutes a risk factor in the occurrence cancer. However, the study showed that there is no difference between the Pro allele and the Arg allele in the patients compared to the controls (OR = 0.95, P = 0.87), which could rule out the possible association between the Arg72Pro polymorphism and the onset of cancer.

The first molecular identification of benzimidazole resistance in Haemonchus contortus from goats in Thailand.

Background and Aim:Haemonchus contortus is one of the major trichostrongyloid nematodes affecting small ruminant production worldwide, especially in tropical and subtropical regions. Adult H. contortus suck the blood from the host abomasum leading to anemia and often death in heavily infected animals. The mainstay of parasitic control is an anthelmintic drug, but long-term drug use may cause drug resistance. The aim of this study was to examine benzimidazole resistance in H. contortus of goats from different regions in Thailand by detecting the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene.Materials and Methods:A total of 121 H. contortus adults were obtained from 31 naturally infected out of 37 slaughtered goats from city abattoirs in five regions of Thailand. The frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene was detected following the allele-specific polymerase chain reaction protocol.Results:The overall genotype frequencies in Thailand were homozygous resistant (RR: 24%), heterozygous (SR: 44.6%), and homozygous susceptible (SS: 31.4%). The allele frequencies were resistant allele (R: 46%) and susceptible allele (S: 54%). The R allele frequency and the RR genotype varied from 30% to 65% and 0% to 43.9%, respectively. The frequency of R alleles was significantly higher in the southern region (0.65) as compared to northern (0.30, p=0.001), western (0.38, p=0.04), and central regions (0.30, p=0.03). The RR genotype was also significantly higher in the southern region (43.9%) versus the northern (0 %, p=0.001), western (11.8%, p=0.012), and central regions (17.4%, p=0.001).Conclusion:This is the first study of the detection of single-nucleotide polymorphisms in codon 200 of the β-tubulin isotype 1 gene of H. contortus from goats in Thailand. These findings are essential and imply that an integrated approach is needed for issues such as drug treatment, farm management, prevention, and control strategies. This is of interest to farmers, veterinarians, and the department of livestock.

HLA-B*51:315, identified using next-generation sequencing-based typing in a Korean individual.

HLA-B*51:315 differs from B*51:01:01:01 by a single nucleotide polymorphism in codon 87 (CAG → CGG).

Influence of a mannose-binding lectin gene polymorphism and exposure to Chlamydia trachomatis on fallopian tube obstruction in Brazilian woman.

Factors influencing fallopian tube occlusion in women with a lower genital tract infection remain incompletely elucidated. We evaluated whether a polymorphism in the mannose-binding lectin (MBL) gene at codon 54 influences the occurrence of fallopian tube blockage in relation to exposure to Chlamydia trachomatis. In a case-control study at The Hospital das Clínicas, University of São Paulo, Brazil, 75 women with hysterosalpingography-documented tubal occlusion and 75 women with patent fallopian tubes were analyzed for detection of single-nucleotide polymorphism in codon 54 of the MBL gene and for IgG anti-C. trachomatis antibodies in their sera. Both groups were matched for age, race, and sexual variables. Prior exposure to C. trachomatis, as evidenced by the presence of IgG antibodies, was comparable in both groups. Detection of the polymorphic MBL allele was more prevalent in women with blocked tubes (p < 0.01), regardless of whether or not there was evidence of prior chlamydial exposure. The level of MBL-related innate immunity influences the consequences of infection by C. trachomatis or other microbes.

Association of Codon 72 of P53 Gene Polymorphism with Chronic Hepatitis C Virus Infection: A Case Control Study

Single nucleotide polymorphism in codon 72 of p53 gene (Arg/Pro) changes p53 protein structure and affects its activities. Hepatitis C virus (HCV) is believed to induce hepatocellular carcinoma and P53 polymorphisms have been associated with human cancers. The aim of this study was to evaluate genetic variants of codon 72 of p53 gene polymorphism in HCV patients and its relationship with HCV infection. The study was conducted on 67 HCV patients, who were referred to medical centers of Mashhad city, Iran, and 73 healthy people from the same region. Genotyping of codon 72 of p53 gene was performed by PCR-RFLP method. The distributions of different alleles of p53 polymorphisms did not differ significantly between groups. The respective proportions of Proline homozygotes, heterozygotes, and Arginine homozygotes were 37.31%, 35.82%, 26.86% in patients and 39.72%, 27.39%, and 32.87% in the control group respectively. However, we found no significant differenece for the allelic or genotype distribution between cases and controls. Our results indicated no strong evidence of association of the p53 polymorphism with HCV infection; however, further investigation is needed in different ethnic groups to elucidate the role of this polymorphism in HCV infection.

Association between catechol-O-methyltransferase Val158Met polymorphism and configural mode of face processing

Human visual system heavily relies on the spatial configuration among facial parts in discriminating faces. There are individual differences in the ability of configural face processing, which are supposed to be partly attributable to genetic predispositions. However, few studies have identified a specific gene linked to configural face processing ability. The present study investigated an association between configural mode of face processing and a single-nucleotide polymorphism in codon 158 of catechol-O-methyltransferase gene (COMT Val158Met polymorphism) using part-spacing paradigm.The results have revealed superior sensitivity to the changes in facial configuration in participants with Met/Met genotype of COMT Val158Met polymorphism compared to the other genotypes. This effect was virtually eliminated when the faces were presented upside–down. There was no group-difference in the ability to detect the change in morphological features of individual facial parts. These results indicate that COMT Val158Met polymorphism partly explains the individual differences in the ability of configural face processing.

Field efficacy of four anthelmintics and confirmation of drug-resistant nematodes by controlled efficacy test and pyrosequencing on a sheep and goat farm in Denmark

We describe a case of anthelmintic resistance on one of the largest organic small ruminant farms in Denmark. The flock was established in 2007 by purchase of animals from other Danish farms and had history of clinical parasitism, high mortality of young stock and anthelmintic treatment failure. In October 2011, 40 lambs and 40 kids were selected for a faecal egg count reduction test (FECRT) with fenbendazole (FBZ), ivermectin (IVM), moxidectin (MOX) and levamisole (LEV). Lambs were treated with the recommended sheep dose of each product while kids received the sheep dose of IVM, 1.5× sheep dose of MOX and 2× sheep dose of FBZ and LEV. Untreated lambs and kids were also included and three methods for calculating faecal egg count (FEC) reduction were compared. In a subsequent investigation, a controlled efficacy test (CET) with FBZ and IVM was performed in lambs infected with Haemonchus contortus and Trichostrongylus colubriformis isolated from adult goats on the farm. Recovered specimens of H. contortus were subjected to pyrosequencing for detection of single nucleotide polymorphisms (SNPs) related to benzimidazole (BZ) resistance. During the FECRT, FECs in untreated lambs dropped significantly by 47%. No FEC reduction was detected in untreated kids. After FBZ treatments, FEC reductions in lambs and kids ranged from 15 to 54% and 49–56%, respectively, according to the different calculation methods. Post IVM treatments, FEC reductions in lambs and kids varied between 71–90% and 81–83%, correspondingly. LEV and MOX reduced FECs by 98–100% in both species. In the CET, FBZ reduced H. contortus worm counts by 52–56% and no reduction in T. colubriformis counts were detected after treatment. IVM eliminated 100% of H. contortus and reduced T. colubriformis counts by 84–92%, according to different calculation methods. Pyrosequencing of isolated H. contortus revealed increased frequencies of the BZ resistance-related SNP in codon 200 of the β-tubulin isotype 1 gene. Frequency of BZ resistance-related SNPs in codons 167 and 198 were very low and did not exceed levels as obtained in the susceptible reference isolate. Anthelmintic resistance was confirmed in this recently established organic farm and low field efficacy of FBZ was verified by CET and pyrosequencing. BZ-resistant populations of H. contortus and T. colubriformis were isolated for the first time in Denmark. Problems with correct dosing of goats, the observed FEC reduction in untreated lambs and the relevance of including a control group in the FECRT are discussed.

Engineering plasmonic nanorod arrays for colon cancer marker detection

Engineering plasmonic nanomaterials or nanostructures towards ultrasensitive biosensing for disease markers or pathogens is of high importance. Here we demonstrate a systematic approach to tailor effective plasmonic nanorod arrays by combining both comprehensive numerical discrete dipole approximations (DDA) simulation and transmission spectroscopy experiments. The results indicate that 200×50nm nanorod arrays with 300×500nm period provide the highest figure of merit (FOM) of 2.4 and a sensitivity of 310nm/RIU. Furthermore, we demonstrate the use of nanorod arrays for the detection of single nucleotide polymorphism in codon 12 of the K-ras gene that are frequently occurring in early stages of colon cancer, with a sensitivity down to 10nM in the presence of 100-fold higher concentration of the homozygous genotypes. Our work shows significant potential of nanorod arrays towards point-of-care applications in diagnosis and clinical studies.

AB0604 Heat Shock Protein Gene-60 (HSP 60) Polymorphism in Behcet's Disease

BackgroundBehcet's Disease (BD) has the hallmarks of complex genetic disorder. The most established genetic marker-HLA B51 does not account for more than 20% of the relative risk in siblings of...

Comparative study of mutations in SNP loci of K-RAS, hMLH1 and hMSH2 genes in neoplastic intestinal polyps and colorectal cancer.

To clarify the molecular mechanism involved in pathogenesis of colorectal cancer as well as clinical significance of genetic analysis of histological samples. A total of 480 blood and tissue specimens were collected in our hospital from January 2011 to October 2012. In the observation group, there were 120 blood specimens and 120 intestinal tract tissue specimens collected from patients with neoplastic intestinal polyps. In the control group I there were 80 blood specimens and 80 intestinal tract tissue specimens collected from patients with colorectal cancer. In the control group II there were 40 blood specimens and 40 intestinal tract tissue specimens collected from healthy individuals. The gene segments were amplified using PCR and DNA gel electrophoresis along with DNA sequence analysis were employed for the detection of the following single nucleotide polymorphisms (SNPs): K-RAS codons 12 and 13; hMLH1 (human mutS homolog 1) gene missense mutation at Va1384Asp; hMSH2 (human mutS homolog 2) gene missense mutation at 2783C/A. The mutation rate of the SNP at Va1384Asp locus of the hMLH1 gene from blood and tissue specimens in the observation group showed no statistical difference from those in the control group I. The mutation rates of SNPs in codons 12 and 13 of K-RAS and at 2783C/A locus of the hMSH2 gene were significantly lower in the observation group than in the control group I (χ(2) = 15.476, 29.670, 10.811, 16.618, 33.538, 7.898, P < 0.05). The mutation rate of SNP at Va1384Asp locus of the hMLH1 gene was significantly higher in the observation group when compared to the control group II (χ(2) = 10.486, 4.876, P < 0.05). The mutation rates of SNPs in codons 12 and 13 of K-RAS and at 2783C/A locus of the hMSH2 gene did not show any statistical difference from those in the control group II. There may be important clinical significance and relevance between neoplastic intestinal polyps and colorectal cancer in terms of the mechanisms involved in the pathogenesis.

Deep amplicon sequencing of preselected isolates of Parascaris equorum in β-tubulin codons associated with benzimidazole resistance in other nematodes.

BackgroundThe development of anthelmintic resistance (AR) to macrocyclic lactones in the equine roundworm Parascaris equorum has resulted in benzimidazoles now being the most widely used substance to control Parascaris infections. However, over-reliance on one drug class is a risk factor for the development of AR. Consequently, benzimidazole resistance is widespread in several veterinary parasites, where it is associated with single nucleotide polymorphisms (SNPs) in drug targets encoded by the β-tubulin genes. The importance of these SNPs varies between different parasitic nematodes, but it has been hypothesised that they occur, at low allele frequencies, even in unselected populations. This study investigated whether these SNPs exist in the P. equorum population and tested the hypothesis that BZ resistance can develop from pre-existing SNPs in codons 167, 198 and 200 of the β-tubulin isotype 1 and 2 genes, reported to be associated with AR in strongylids. The efficacy of the oral paste formula fenbendazole on 11 farms in Sweden was also assessed.MethodsTwo isotype-specific primer pairs were designed, one on either side of the codon 167 and one on either side of codons 198 and 200. A pool of 100 000 larvae was sequenced using deep amplicon sequencing by Illumina HiSeq. Faecal egg count reduction test was used to assess the efficacy of fenbendazole.ResultsNo SNPs were observed in codons 167, 198 or 200 of the β-tubulin isotype 1 or 2 genes of P. equorum, even though 100 000 larvae were sequenced. Faecal egg count reduction testing of fenbendazole showed that this anthelmintic was still 100% effective, meaning that the likelihood of finding high allele frequency of SNPs associated with benzimidazoles resistance in P. equorum was low. Unexpectedly, the allele frequencies observed in single worms were comparable to those in pooled samples.ConclusionsWe concluded that fenbendazole does not exert selection pressure on the β-tubulin genes of isotypes 1 and 2 in P. equorum. The fact that no pre-existing SNPs were found in codons 167, 198 and 200 in P. equorum also illustrates the difficulties in generalising about AR mechanisms between different taxonomic groups of nematodes.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-3305-7-410) contains supplementary material, which is available to authorized users.

Genetic variations in the beta-tubulin gene and the internal transcribed spacer 2 region of Trichuris species from man and baboons.

BackgroundThe whipworm Trichuris trichiura has been estimated to infect 604 – 795 million people worldwide. The current control strategy against trichuriasis using the benzimidazoles (BZs) albendazole (400 mg) or mebendazole (500 mg) as single-dose treatment is not satisfactory. The occurrence of single nucleotide polymorphisms (SNPs) in codons 167, 198 or 200 of the beta-tubulin gene has been reported to convey BZ-resistance in intestinal nematodes of veterinary importance. It was hypothesised that the low susceptibility of T. trichiura to BZ could be due to a natural occurrence of such SNPs. The aim of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal transcribed spacer 2 region (ITS2).MethodsNucleotide sequences of the beta-tubulin gene were generated by PCR using degenerate primers, specific primers and DNA from worms and eggs of T. trichiura and worms of Trichuris spp. from baboons. The ITS2 region was amplified using adult Trichuris spp. from baboons. PCR products were sequenced and analysed. The beta-tubulin fragments were studied for SNPs in codons 167, 198 or 200 and the ITS2 amplicons were compared with GenBank records of T. trichiura.ResultsNo SNPs in codons 167, 198 or 200 were identified in any of the analysed Trichuris spp. from humans and baboons. Based on the ITS2 region, the similarity between Trichuris spp. from baboons and GenBank records of T. trichiura was found to be 98 – 99%.ConclusionsSingle nucleotide polymorphisms in codon 167, 198 and 200, known to confer BZ-resistance in other nematodes, were absent in the studied material. This study does not provide data that could explain previous reports of poor BZ treatment efficacy in terms of polymorphism in these codons of beta-tubulin. Based on a fragment of the beta-tubulin gene and the ITS2 region sequenced, it was found that T. trichiura from humans and Trichuris spp. isolated from baboons are closely related and may be the same species.

Genetic variation in codons 167, 198 and 200 of the beta-tubulin gene in whipworms (Trichuris spp.) from a range of domestic animals and wildlife

A recurrent problem in the control of whipworm (Trichuris spp.) infections in many animal species and man is the relatively low efficacy of treatment with a single application of benzimidazoles (BZs). The presence of single nucleotide polymorphisms (SNPs) in codons 167, 198 and 200 in the beta-tubulin gene has been associated with BZ anthelmintic resistance in intestinal nematodes of veterinary importance. We hypothesized that the low susceptibility to BZ could be related to a natural tolerance or induced resistance caused by BZ-resistant associated SNPs. The aim of the present study was therefore to investigate the presence of these SNPs in the beta-tubulin gene of Trichuris spp. obtained from a range of animals.DNA was extracted from a total of 121 Trichuris spp. adult whipworm specimens obtained from 6 different host species. The number of worms from each host was pig: 31, deer: 21, sheep: 18, mouse: 17, dog: 19 and Arabian camels: 14. A pooled sample of Trichuris eggs from 3 moose was also used. In order to amplify the beta-tubulin fragments which covered codons 167, 198 and 200 of the gene, degenerate primers were designed. The sequences obtained were used to design species specific primers and used to amplify a ∼476bp fragment of the beta-tubulin gene. The PCR products were sequenced, analysed and evaluated.We did not identify SNPs in codons 167, 198 or 200 that led to amino acid substitutions in any of the studied Trichuris spp., but genetic variation expected to be related to species differences was observed. The cluster analysis showed close evolutionary relationship between Trichuris spp. from ruminants and between mouse and dog whereas the pig-derived worms, T. suis, clustered with T. trichiura obtained from Genbank.

MDM2 T309G has a Synergistic Effect with P21 ser31arg Single Nucleotide Polymorphisms on the Risk of Acute Myeloid Leukemia

The P53 tumor suppressor gene plays a pivotal role in maintaining cellular homeostasis by preventing the propagation of genome mutations. P53 in its transcriptionally active form is capable of activating distinct target genes that contribute to either apoptosis or growth arrest, like P21. However, the MDM2 gene is a major negative regulator of P53. Single nucleotide polymorphisms (SNP) in codon Arg72Pro of P53 results in impairment of the tumor suppressor activity of the gene. A similar effect is caused by a SNP in codon 31 of P21. In contrast, a SNP in position 309 of MDM2 results in increased expression due to substitution of thymine by guanine. All three polymorphisms have been associated with increased risk of tumorigenesis. We aimed to study the prevalence of SNPs in the P53 pathway involving the three genes, P53, P21 and MDM2, among acute myeloid leukemia (AML) patients and to compare it to apparently normal healthy controls for assessment of impact on risk. We found that the P21 ser31arg heterozygous polymorphism increases the risk of AML (P value=0.017, OR=2.946, 95% CI=1.216-7.134). Although the MDM2 309G allele was itself without affect, it showed a synergistic effect with P21 ser/arg polymorphism (P value=0.003, OR= 6.807, 95% CI= 1.909-24.629). However, the MDM2 309T allele abolish risk effect of the P21 polymorphic allele (P value= 0.71). There is no significant association of P53 arg72pro polymorphism on the risk of AML. We suggest that SNPs in the P53 pathway, especially the P21 ser31arg polymorphism and combined polymorphisms especially the P21/ MDM2 might be genetic susceptibility factors in the pathogenesis of AML.

Abstract 1158: Clinical significance of p53 codon 72 polymorphism in hepatocellular carcinomas

Abstract Purpose: We recently demonstrated that, in colorectal carcinomas, the presence of a single nucleotide polymorphism (SNP) at codon 72 of the p53 gene was associated with a poor outcome for African American (AA) patients. Since such studies have not been performed for hepatocellular carcinomas (HCCs), we determined, for AAs and non-Hispanic Caucasians (NHCAs), the prevalence of p53 SNPs in codon 72 of HCCs and its association with adverse clinical and pathological features. Methods: DNA samples extracted from 48 archived, formalin-fixed, paraffin-embedded HCC tissues and from matching, uninvolved liver were analyzed for the mutational status of the p53 gene by sequencing exon 4 through exon 9. The results obtained were correlated with the demographic and clinicopathological features of the HCCs and with patient survival. Results: Overall, the frequency of missense point mutations in p53 of HCCs was low (6 of 48, 12%). Missense point mutations, however, were common in NHCAs (4 of 6). Genotyping of codon 72 of p53 demonstrated that the Arg/Arg phenotype had the highest frequency (27 of 48; 56%), followed by Arg/Pro (16 of 48; 33%) and Pro/Pro (5 of 48; 11%). Four of five patients with the Pro/Pro phenotype were AAs (χ2 p = 0.028). Of these, three of the four tumors had high proliferative (ki67) indices; two of the four were poorly differentiated. In contrast, poorly differentiated tumors were few in Arg/Arg (1 of 27, 4%) and Arg/Pro (1 of 16; 6%) (χ2p = 0.016) phenotype groups. For all patients, the Pro/Pro phenotype were associated with hepatitis C virus (HCV) infection (χ2 p = 0.048). Furthermore, AAs with the Pro/Pro phenotype had lower median survival (15.5 months) compared to those with the Arg/Arg and Arg/Pro (32 months) phenotypes. NHCA patients with missense point mutations had shorter median survival (22.5 months) relative to NHCAs with wild-type p53 (34 months).Conclusion: These preliminary findings suggest that, in AAs, the Pro/Pro phenotype at codon 72 of the p53 gene is associated with aggressive tumor behavior, shorter median survival, and HCV infection. These pilot studies were supported jointly by a Charles Barkley Award through the UAB Minority Health Disparities Research Center (MHRC) and the UAB Center for Clinical and Translational Science (5UL1 RR025777-04). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1158. doi:1538-7445.AM2012-1158

Molecular technologies used in detecting of sensitive and isoniazid-resistant Mycobacterium tuberculosis

Two variants for the detection of single nucleotide polymorphisms in codon 315 of the katG gene of Mycobacterium tuberculosis (MTB) (mutations in this gene are associated with resistance to isoniazid, which is an antituberculosis drug of the first line) have been developed. Two sets of primers, either of which included an additional competitive blocking primer with a 3′-terminal phosphate group (in order to prevent nonspecific amplification), permitted the identification of the most frequent AGC → ACC and AGC → AGA point mutations in codon 315 of the katG gene. Conduction of PCR with a set of two primers, one of which contained five LNA monomers, permitted the detection of any of the six known mutations in codon 315 of the katG gene and, thereby, for the discrimination between isoniazid-sensitive and isoniazid-resistant MTB. The purity and structure of the 17 bp long primers containing LNA-modified nucleotides were characterized by time-of-flight MALDI mass spectrometry, and the 17 bp duplex formed by two LNA-containing complementary oligonucleotides was analyzed by thermal denaturation. The molecular genetic test systems created for differentiating between the wild-type MTB isolates and isoniazid-resistant MTB (an antituberculosis drug of the first line) can be used in clinical laboratories equipped with standard PCR devices; such systems permit the shortening of the time required for the detection of isoniazid resistance of MTB: from 1–3 months by the standard bacteriological methods to 1–3 days by PCR.

Association between mannose-binding lectin and interleukin-1 receptor antagonist gene polymorphisms and recurrent vulvovaginal candidiasis

The influence of functional polymorphisms in the genes coding for mannose-binding lectin (MBL) and interleukin-1 receptor antagonist (IL-1ra) on recurrent vulvovaginal candidiasis (RVVC) were examined in an urban Brazilian population. DNA was isolated from buccal swabs of 100 women with RVVC and 100 control women and tested by gene amplification for a single nucleotide polymorphism in codon 54 of the MBL2 gene and for a length polymorphism in intron 2 of the IL1RN gene. Genotype and allele frequencies were compared between groups. The frequency of the variant MBL2 B allele, associated with reduced circulating and vaginal MBL concentrations, was 27.0% in RVVC and 8.5% in control women (p<.0001). The MBL2 B,B genotype was present in 12% of RVVC patients and 1% of controls (p=.0025). The IL1RN 2 allele frequency, associated with the highest level of unopposed IL-1β activity, was 24.0% in RVVC and 23.4% in controls. The IL1RN genotype distribution was also similar in both groups. Carriage of the MBL2 codon 54 polymorphism, but not the IL1RN length polymorphism, predisposes to RVVC in Brazilian women.

Single-Nucleotide Polymorphism in the fadD28 Gene as a Genetic Marker for East Asia Lineage Mycobacterium tuberculosis

Mycobacterium tuberculosis isolates with a region of difference 105 (RD105) deletion, mainly Beijing family spoligotypes, were phylogenetically grouped into the East Asia lineage. We identified a single nucleotide polymorphism in codon 507, ATC to ATT, of the fadD28 gene as a robust marker and developed a rapid assay for East Asia lineage M. tuberculosis.

MDM2 SNP309 and TP53 SNPArg72Pro Polymorphisms in Myelodysplastic Syndrome.

Abstract 1745Poster Board I-771 IntroductionMyelodysplastic syndrome (MDS) encompasses a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, refractory cytopenia and a tendency to progress towards acute myeloid leukemia (AML). The progression of the disease may be associated with genetic or epigenetic alterations and a possible change in protein function. MDM2/P53 pathway plays an important role in the control of apoptotic and proliferation mechanisms. Single nucleotide polymorphisms (SNPs) were identified in the TP53 and MDM2 genes. MDM2 SNP309 results in higher levels of MDM2 and attenuates p53 pathway. The SNP in codon 72 of the TP53 gene results in either a C or G nucleotide and leads to either Proline (Pro) or Arginine (Arg), respectively. The Arg variant has been shown to be more potent in apoptosis induction and the Pro variant has been shown to be better in inducing cell-cycle arrest and to have a greater ability to repair damaged-DNA. The aim of the present study was to investigate the incidence of MDM2 and TP53 polymorphisms in MDS patients and to correlate the frequency of these SNPs with age, neutrophis and platelets at diagnosis, low risk versus high risk disease according to FAB (RA and RARS versus AREB and AREBt) and IPSS (Low and Int-1 versus Int-2 and high), cytogenetic risk (low versus intermediate and high risk), disease progression and overall survival. Patients and MethodsWe studied 103 healthy controls and 63 patients with MDS. According to FAB, patients were distributed as follows: 43 RA, 10 RARS, 7 RAEB, 1 RAEBt and 2 CMML. The median follow-up time was 40 months (range 2 – 159 months). Samples were obtained from peripheral blood or bone marrow and were screened for the presence of polymorphisms MDM2 SNP309 and TP53 SNPArg72Pro, by PCR analysis with specific primers and appropriate restriction enzyme. Appropriate statistical analyses were used for each test. ResultsThe frequencies of genotypes for MDM2 SNP309 and TP53Pro7Arg were similar between MDS and healthy controls; MDM2 SNP309: 51% vs 53%, for TT, 38% vs 32% for TG, and 11% vs 15% for GG, TP53Pro7Arg: 47.5% vs 44%, for Arg/Arg, 47,5% vs 42% for Pro/Arg, and 5% vs 14% for Pro/Pro. No differences were observed between MDS patients with presence or absence of the polymorphisms in relation to age, neutrophis and platelets at diagnosis, low risk versus high risk disease according to FAB, IPSS and cytogenetic risk, disease progression and overall survival. ConclusionsMDM2 and TP53 polymorphisms have been described to affect the risk for cancer, onset age and overall survival in solid tumors and leukemias. This was the first study to report these SNPs in MDS and leads to believe that these polymorphisms are not associated with risk for the disease and with clinical data. Keywords: MDM2, p53, myelodysplasia, polymorphisms DisclosuresNo relevant conflicts of interest to declare.

Association of functional polymorphisms of the transforming growth factor B1 gene with survival and graft-versus-host disease after unrelated donor hematopoietic stem cell transplantation

Many genetic factors play major roles in the outcome of hematopoietic stem cell transplants from unrelated donors. Transforming growth factor beta1 is a member of a highly pleiotrophic family of growth factors involved in the regulation of numerous immunomodulatory processes. We investigated the impact of single nucleotide polymorphisms at codons 10 and 25 of TGFB1, the gene encoding for transforming growth factor beta1, on outcomes in 427 mye-loablative-conditioned transplanted patients. In addition, transforming growth factor beta1 plasma levels were measured in 263 patients and 327 donors. Patients homozygous for the single nucleotide polymorphism at codon 10 had increased non-relapse mortality (at 3 years: 46.8% versus 29.4%, P=0.014) and reduced overall survival (at 5 years 29.3% versus 42.2%, P=0.013); the differences remained statistically significant in multivariate analysis. Donor genotype alone had no impact, although multiple single nucleotide polymorphisms within the pair were significantly associated with higher non-relapse mortality (at 3 years: 44% versus 29%, P=0.021) and decreased overall survival (at 5 years: 33.8% versus 41.9%, P=0.033). In the 10/10 HLA matched transplants (n=280), recipients of non-wild type grafts tended to have a higher incidence of acute graft-versus-host disease grades II-IV (P=0.052). In multivariate analysis, when analyzed with patients' genotype, the incidences of both overall and grades II-IV acute graft-versus-host disease were increased (P=0.025 and P=0.009, respectively) in non-wild-type pairs. We conclude that increasing numbers of single nucleotide polymorphisms in codon 10 of TGFB1 in patients and donors are associated with a worse outcome following hematopoietic stem cell transplantation from unrelated donors.