999 resultados para Chromosome 22


Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE Endogenous uveitis is a major cause of visual loss mediated by the immune system. The protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene encodes a lymphoid-specific phosphatase that plays a key role in T-cell receptor (TCR) signaling. Two independent functional missense single nucleotide polymorphisms (SNPs) located within the PTPN22 gene (R263Q and R620W) have been associated with different autoimmune disorders. We aimed to analyze for the first time the influence of these PTPN22 genetic variants on endogenous non-anterior uveitis susceptibility. METHODS We performed a case-control study of 217 patients with endogenous non-anterior uveitis and 718 healthy controls from a Spanish population. The PTPN22 polymorphisms (rs33996649 and rs2476601) were genotyped using TaqMan allelic discrimination assays. The allele, genotype, carriers, and allelic combination frequencies were compared between cases and controls with χ(2) analysis or Fisher's exact test. RESULTS Our results showed no influence of the studied SNPs in the global susceptibility analysis (rs33996649: allelic P- value=0.92, odds ratio=0.97, 95% confidence interval=0.54-1.75; rs2476601: allelic P- value=0.86, odds ratio=1.04, 95% confidence interval=0.68-1.59). Similarly, the allelic combination analysis did not provide additional information. CONCLUSIONS Our results suggest that the studied polymorphisms of the PTPN22 gene do not play an important role in the pathophysiology of endogenous non-anterior uveitis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Erétrie est l'une de ces cités qui ont fait la grandeur de la Grèce antique. La ville a conservé d'importants vestiges, dont plusieurs chefs-d'oeuvre artistiques. Depuis 1964, des archéologues suisses en poursuivent l'exploration commencée il y a plus d'un siècle. De ces recherches, menées en étroite collaboration avec les autorités grecques, est né le projet d'offrir pour la première fois au public un aperçu de la vie d'une cité grecque à travers quelque 500 objets de prestige et de la vie courante. L'ouvrage accompagne une exposition, organisée par l'Ecole suisse d'archéologie en Grèce, en collaboration avec l'Antikenmuseum Basel und Sammlung Ludwig

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND Multiple Sclerosis (MS) is an autoimmune demyelinating disease that occurs more frequently in women than in men. Multiple Sclerosis Associated Retrovirus (MSRV) is a member of HERV-W, a multicopy human endogenous retroviral family repeatedly implicated in MS pathogenesis. MSRV envelope protein is elevated in the serum of MS patients and induces inflammation and demyelination but, in spite of this pathogenic potential, its exact genomic origin and mechanism of generation are unknown. A possible link between the HERV-W copy on chromosome Xq22.3, that contains an almost complete open reading frame, and the gender differential prevalence in MS has been suggested. RESULTS MSRV transcription levels were higher in MS patients than in controls (U-Mann-Whitney; p = 0.004). Also, they were associated with the clinical forms (Spearman; p = 0.0003) and with the Multiple Sclerosis Severity Score (MSSS) (Spearman; p = 0.016). By mapping a 3 kb region in Xq22.3, including the HERV-W locus, we identified three polymorphisms: rs6622139 (T/C), rs6622140 (G/A) and rs1290413 (G/A). After genotyping 3127 individuals (1669 patients and 1458 controls) from two different Spanish cohorts, we found that in women rs6622139 T/C was associated with MS susceptibility: [χ2; p = 0.004; OR (95% CI) = 0.50 (0.31-0.81)] and severity, since CC women presented lower MSSS scores than CT (U-Mann-Whitney; p = 0.039) or TT patients (U-Mann-Whitney; p = 0.031). Concordantly with the susceptibility conferred in women, rs6622139*T was associated with higher MSRV expression (U-Mann-Whitney; p = 0.003). CONCLUSIONS Our present work supports the hypothesis of a direct involvement of HERV-W/MSRV in MS pathogenesis, identifying a genetic marker on chromosome X that could be one of the causes underlying the gender differences in MS.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are very few disease-specific studies focusing on outcomes of umbilical cord blood transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia. We report the outcome of 45 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia who underwent myeloablative single unit cord blood transplantation from unrelated donors within the GETH/GITMO cooperative group. Conditioning regimens were based on combinations of thiotepa, busulfan, cyclophospamide or fludarabine, and antithymocyte globulin. At the time of transplantation, 35 patients (78%) were in first complete remission, four (8%) in second complete remission and six (14%) in third or subsequent response. The cumulative incidence of myeloid engraftment was 96% at a median time of 20 days and significantly better for patients receiving higher doses of CD34(+) cells. The incidence of acute grade II-IV graft-versus-host disease was 31%, while that of overall chronic graft-versus-host disease was 53%. Treatment-related mortality was 17% at day +100 and 31% at 5 years. The 5-year relapse, event-free survival and overall survival rates were 31%, 36% and 44%, respectively. Although the event-free and overall survival rates in patients without BCR/ABL transcripts detectable at time of transplant were better than those in whom BCR/ABL transcripts were detected (46% versus 24% and 60% versus 30%, respectively) these differences were not statistically significant in the univariate analysis (P=0.07). These results demonstrate that umbilical cord blood transplantation from unrelated donors can be a curative treatment for a substantial number of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Genetic crosses in many organisms have shown that alleles of unlinked genes generally assort independently of one another during gamete formation. However, variation in chromosome size may affect the process of meiosis and lead to nonindependent assortment of chromosomes. We therefore examined chromosomes with insertions and found that they preferentially segregated away from the X chromosome during meiosis in Caenorhabditis elegans males. Conversely, chromosomes with deletions preferentially segregated with the X chromosome. The degree of segregation bias was significantly associated with the length of the insertion or deletion. Simulations revealed that this segregation bias leads to genome size reduction in hermaphroditic species, a pattern consistent with differences in genome sizes in the genus Caenorhabditis. These results suggest that insertions and deletions may affect chromosome segregation patterns.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ultrasound scans in the mid-trimester of pregnancy are now a routine part of antenatal care in most European countries. Using data from registries of congenital anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of limb reduction deficiencies (LRD) by routine ultrasonographic examination of the fetus. All LRDs suspected prenatally and all LRDs (including chromosome anomalies) confirmed at birth were identified from 20 Congenital Malformation Registers from the following 12 European countries: Austria, Croatia, Denmark, France, Germany, Italy, Lithuania, Spain, Switzerland, The Netherlands, UK and Ukrainia. These registries are following the same methodology. During the study period (1996-98) there were 709,030 births, and 7,758 cases with congenital malformations including LRDs. If more than one LRD was present the case was coded as complex LRD; 250 cases of LRDs with 63 (25.2%) termination of pregnancies were identified including 138 cases with isolated LRD, 112 with associated malformations, 16 with chromosomal anomalies and 38 non chromosomal recognized syndromes. The prenatal detection rate of isolated LRD was 24.6% (34 out of 138 cases) compared with 49.1% for associated malformations (55 out of 112; p<0.01). The prenatal detection of isolated terminal transverse LRD was 22.7% (22 out of 97), 50% (3 out of 6) for proximal intercalary LRD, 8.3% (1 out of 12) for longitudinal LRD and 0 for split hand/foot; for multipli-malformed children with LRD those percentages were 46.1% (30 out of 65), 66.6% (6 out of 9), 57.1% (8 out of 14) and 0 (0 out of 2), respectively. The prenatal detection rate of LRDs varied in relation with the ultrasound screening policies from 20.0% to 64.0% in countries with at least one routine fetal scan.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The prognostic relevance of additional cytogenetic findings at diagnosis of chronic myeloid leukemia (CML) is unclear. The impact of additional cytogenetic findings at diagnosis on time to complete cytogenetic (CCR) and major molecular remission (MMR) and progression-free (PFS) and overall survival (OS) was analyzed using data from 1151 Philadelphia chromosome-positive (Ph(+)) CML patients randomized to the German CML Study IV. At diagnosis, 1003 of 1151 patients (87%) had standard t(9;22)(q34;q11) only, 69 patients (6.0%) had variant t(v;22), and 79 (6.9%) additional cytogenetic aberrations (ACAs). Of these, 38 patients (3.3%) lacked the Y chromosome (-Y) and 41 patients (3.6%) had ACAs except -Y; 16 of these (1.4%) were major route (second Philadelphia [Ph] chromosome, trisomy 8, isochromosome 17q, or trisomy 19) and 25 minor route (all other) ACAs. After a median observation time of 5.3 years for patients with t(9;22), t(v;22), -Y, minor- and major-route ACAs, the 5-year PFS was 90%, 81%, 88%, 96%, and 50%, and the 5-year OS was 92%, 87%, 91%, 96%, and 53%, respectively. In patients with major-route ACAs, the times to CCR and MMR were longer and PFS and OS were shorter (P < .001) than in patients with standard t(9;22). We conclude that major-route ACAs at diagnosis are associated with a negative impact on survival and signify progression to the accelerated phase and blast crisis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ape chromosomes homologous to human chromosomes 14 and 15 were generated by a fission event of an ancestral submetacentric chromosome, where the two chromosomes were joined head-to-tail. The hominoid ancestral chromosome most closely resembles the macaque chromosome 7. In this work, we provide insights into the evolution of human chromosomes 14 and 15, performing a comparative study between macaque boundary region 14/15 and the orthologous human regions. We construct a 1.6-Mb contig of macaque BAC clones in the region orthologous to the ancestral hominoid fission site and use it to define the structural changes that occurred on human 14q pericentromeric and 15q subtelomeric regions. We characterize the novel euchromatin-heterochromatin transition region (∼20 Mb) acquired during the neocentromere establishment on chromosome 14, and find it was mainly derived through pericentromeric duplications from ancestral hominoid chromosomes homologous to human 2q14-qter and 10. Further, we show a relationship between evolutionary hotspots and low-copy repeat loci for chromosome 15, revealing a possible role of segmental duplications not only in mediating but also in "stitching" together rearrangement breakpoints.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Y chromosome variation is determined by several confounding factors including mutation rate, effective population size, demography, and selection. Disentangling these factors is essential to better understand the evolutionary properties of the Y chromosome. We analyzed genetic variation on the Y chromosome, X chromosome, and mtDNA of the greater white-toothed shrew, a species with low variance in male reproductive success and limited sex-biased dispersal, which enables us to control to some extent for life-history effects. We also compared ancestral (Moroccan) to derived (European) populations to investigate the role of demographic history in determining Y variation. Recent colonization of Europe by a small number of founders (combined with low mutation rates) is largely responsible for low diversity observed on the European Y and X chromosomes compared to mtDNA. After accounting for mutation rate, copy number, and demography, the Y chromosome still displays a deficit in variation relative to the X in both populations. This is possibly influenced by directional selection, but the slightly higher variance in male reproductive success is also likely to play a role, even though the difference is small compared to that in highly polygynous species. This study illustrates that demography and life-history effects should be scrutinized before inferring strong selective pressure as a reason for low diversity on the Y chromosome.