1,721,178 research outputs found
Origins of Oocyte Aneuploidy
No full textThe low reproductive potential of the human species is mainly caused by aneuploidies affecting embryo o fetal development. Although some of these aneuploidies may be paternally inherited or generated mitotically during preimplantation development, the vast majority of aneuploid karyotypes are generated at fertilization as an effect of meiotic errors occurring during the oocyte life cycle. Formation of an aneuploid oocyte derives from chromosome non-disjunction or premature segregation of sister chromatids at meiosis I or II. Less clear is why aneuploidy occurs. Advanced maternal age is strongly positively associated with the prevalence of aneuploidies, including Down syndrome, in spontaneously aborted fetuses and newborns. However, the links that connect maternal age and the cellular mechanisms that are involved in chromosome mal-segregation remain unknown. Factors that may play a role in the generation of aneuploidies are diverse. For example, number and position relative to the centromere of chiasmata formed in the process of recombination during fetal life influence the regularity of chromosome segregation during adult life. Alterations in the profile of the hormonal milieu are also suspected to cause oocyte aneuploidy. Environmental agents and certain lifestyles are believed to be additional factors that expose oocytes to an increased risk of chromosome mal-segregation. Better understanding of the nature and action of these factors could offer future opportunities for preventing at least part of the aneuploidies occurring in the female germ cell
BRCA1 and BRCA2 molecular testing in women with different risk of hereditary breast cancer: Cost/effectiveness and psychological implications
No full textSince the discovery of the familial breast cancer susceptibility genes BRCA1 and BRCA2, genetic counseling and molecular analysis in the identification of mutations responsible for the increased risk of breast and ovarian cancer have become crucial steps in the clinical practice. In fact, the identification of pathogenic BRCA1/2 mutations provides useful information about the risk of a second cancer in the proband, the possible presence of the same mutation in healthy relatives of the patient and the different preventative and therapeutic approaches. However, due to the high costs and some technical limitations, the cost effectiveness ratio of BRCA1/2 gene testing should be carefully evaluated in the different cases, considering the psychological implications related to this kind of analysis. In this review, the different criteria for the selection of patients, the role of genetic counseling and the different approaches for the molecular analysis will be discussed, in order to provide a picture of the different strategies aimed to increase the sensitivity and specificity of BRCA1/2 genetic testing
Human height genes and cancer.
No full textBody development requires the ability to control cell proliferation and metabolism, together with selective 'invasive' cell migration for organogenesis. These requirements are shared with cancer. Human height-associated loci have been recently identified by genome-wide SNP-association studies. Strikingly, most of the more than 100 genes found associated to height appear linked to neoplastic growth, and impose a higher risk for cancer. Height-associated genes drive the HH/PTCH and BMP/TGFβ pathways, with p53, c-Myc, ERα, HNF4A and SMADs as central network nodes. Genetic analysis of body-size-affecting diseases and evidence from genetically-modified animals support this model. The finding that cancer is deeply linked to normal, body-plan master genes may profoundly affect current paradigms on tumor development
Combined fluorescence in situ hybridization and PRINS for the analysis of the Dystrophin gene
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Different approaches in the molecular analysis of the SHOX gene dysfunctions
No full textDeficit of the short stature homeobox containing gene (SHOX) accounts for 2.15% of cases of idiopathic short stature (ISS) and 50-100% of cases of Leri-Weill dyschondrosteosis (LWD). It has been demonstrated that patients with SHOX deficit show a good response to treatment with GH. Thus, the early identification of SHOX alterations is a crucial point in order to choose the best treatment for ISS and LWD patients. In this study, we analyze the most commonly used molecular techniques for the detection of SHOX gene alterations. multiple ligation-dependent probe amplification analysis appears to represent the gold standard for the detection of deletion involving the SHOX gene or the enhancer region, being able to show both alterations in a single assay
Epigenetics and male reproduction: the consequences of paternal lifestyle on fertility, embryo development, and children lifetime health
Full text linkThe correlation between epigenetics and human reproduction represents a very interesting field of study, mainly due to the possible transgenerational effects related to epigenetic modifications of male and female gametes. In the present review, we focused our attention to the role played by epigenetics on male reproduction, evidencing at least four different levels at which sperm epigenetic modifications could affect reproduction: (1) spermatogenesis failure; (2) embryo development; (3) outcome of assisted reproduction technique (ART) protocols, mainly as concerning genomic imprinting; and (4) long-term effects during the offspring lifetime. The environmental agents responsible for epigenetic modifications are also examined, suggesting that the control of paternal lifestyle prior to conception could represent in the next future a novel hot topic in the management of human reproduction
Fluorescence in situ hybridization analysis of minimal residual disease and the relevance of the der(9) deletion in imatinib-treated patients with chronic myeloid leukemia.
No full textForty-six patients with chronic myeloid leukemia
receiving imatinib mesylate (39 in chronic phase,
one in accelerated phase, and six in blastic crisis),
were studied for a 20-62 month follow-up period
by cytogenetics and fluorescence in situ hybridization
using dual-color, dual-fusion BCR and ABL
probes. This approach provided valuable results
for disease management of analysis
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