Publications (10)29.81 Total impact
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Article: Re: Questions about the accuracy of polar body analysis for preimplantation genetic screening.
Human Reproduction 03/2013; · 4.47 Impact Factor -
Article: Chromosomal microarray analysis as a first-line test in pregnancies with a priori low risk for the detection of submicroscopic chromosomal abnormalities.
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ABSTRACT: In this study, we aimed to explore the utility of chromosomal microarray analysis (CMA) in groups of pregnancies with a priori low risk for detection of submicroscopic chromosome abnormalities, usually not considered an indication for testing, in order to assess whether CMA improves the detection rate of prenatal chromosomal aberrations. A total of 3000 prenatal samples were processed in parallel using both whole-genome CMA and conventional karyotyping. The indications for prenatal testing included: advanced maternal age, maternal serum screening test abnormality, abnormal ultrasound findings, known abnormal fetal karyotype, parental anxiety, family history of a genetic condition and cell culture failure. The use of CMA resulted in an increased detection rate regardless of the indication for analysis. This was evident in high risk groups (abnormal ultrasound findings and abnormal fetal karyotype), in which the percentage of detection was 5.8% (7/120), and also in low risk groups, such as advanced maternal age (6/1118, 0.5%), and parental anxiety (11/1674, 0.7%). A total of 24 (0.8%) fetal conditions would have remained undiagnosed if only a standard karyotype had been performed. Importantly, 17 (0.6%) of such findings would have otherwise been overlooked if CMA was offered only to high risk pregnancies.The results of this study suggest that more widespread CMA testing of fetuses would result in a higher detection of clinically relevant chromosome abnormalities, even in low risk pregnancies. Our findings provide substantial evidence for the introduction of CMA as a first-line diagnostic test for all pregnant women undergoing invasive prenatal testing, regardless of risk factors.European Journal of Human Genetics advance online publication, 5 December 2012; doi:10.1038/ejhg.2012.253.European journal of human genetics: EJHG 12/2012; · 3.56 Impact Factor -
Article: Sequential comprehensive chromosome analysis on polar bodies, blastomeres and trophoblast: insights into female meiotic errors and chromosomal segregation in the preimplantation window of embryo development.
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ABSTRACT: STUDY QUESTION: What is the optimal stage from oocyte through preimplantation embryo development for biopsy and preimplantation genetic screening (PGS) to detect abnormal chromosome segregation patterns in eggs or embryos from advanced maternal age (AMA) patients? SUMMARY ANSWER: Testing at the polar body (PB) stage was the least accurate mainly due to the high incidence of post-zygotic events. This suggests that postponing the time of biopsy to the blastocyst stage of preimplantation embryo development may provide the most reliable results for PGS. WHAT IS KNOWN ALREADY: In the PGS field there is an ongoing debate about the optimal biopsy stage for PGS. This is a result of the lack of understanding of how aneuploidy arises in the human embryo. To date, most of the cytogenetic data obtained during PGS investigations have been derived through the analysis of cells at isolated points in the preimplantation window, thus potentially missing critical information on chromosomal segregation. Understanding the chromosome segregation patterns during preimplantation development holds the potential to significantly increase the success rates of IVF. In this study, a sequential comprehensive chromosome analysis of both the PBs and the corresponding embryos at both the cleavage and the blastocyst stages is presented. STUDY DESIGN, SIZE, DURATION: This is a prospective longitudinal cohort study performed between October 2009 and August 2011 involving 9 infertile couples and 21 sets of complete comprehensive chromosomal screening data, including PB1, PB2, corresponding blastomeres and trophectoderm (TE) samples. PARTICIPANTS/MATERIALS, SETTING, METHODS: Infertile couples undergoing IVF cycles with PGS where the female partner was older than 40 years and with a good response to controlled ovarian stimulation (>10 MII oocytes retrieved) were enrolled into the study. The exclusion criteria were (i) patients presenting with abnormal karyotype; (ii) specific ovarian pathologies including polycystic ovary syndrome, endometriosis grade III or higher and premature ovarian failure and (iii) severe male factor infertility (motile sperm count of <500 000/ml after preparation of a fresh ejaculate). The PBs, blastomere and TE samples were sequentially biopsied and analyzed by array comparative genomic hybridization (aCGH). The analysis of chromosome segregation patterns was performed to infer the origin of aneuploidy and to investigate the diagnostic accuracy of both PB and cleavage-stage PGS strategies. MAIN RESULTS AND THE ROLE OF CHANCE: Twenty-one sets of complete data (PB1/PB2/blastomere/TE) including 84 aCGH experiments showed a pattern of multiple meiotic errors typically caused by sister chromatid separation errors and predominantly arising in the second meiotic division. Twenty-two of the 24 (91.7%) errors in the first meiotic division arose as a consequence of premature sister chromatid predivision. In half of these cases, the second meiotic division resulted in a balancing chromosome segregation event producing a normal female complement for that chromosome in the resulting embryo. Overall, only 62 out of 78 (79.5%) of the abnormal meiotic segregations had errors in the either one or both PBs consistent with the aneuploidies observed in their resulting embryos. Ten of the 21 (47.6%) embryos had aneuploidies other than female meiotic-derived ones, most of which detected on Day 3 and confirmed on Day 5 or 6 of embryo development (20/25) with chromosomal loss being three times more frequent than gains. Notably, as high as 20% of female-derived aneuploidies detected on PBs and confirmed on Day 3 were rescued at the blastocyst stage, mainly as a result of diploidization of trisomic chromosomes. On a per chromosome basis, the sensitivity in predicting blastocyst chromosomal complement was significantly lower for PB approach, 61.7%, compared with blastomeres analysis, 86.4% (P < 0.01). LIMITATIONS, REASONS FOR CAUTION: The study was limited to the analysis of oocytes and embryos from AMA patients. Thus, these findings apply only to this patient group. Comparisons with other patient populations including patients with different indications for PGS should be made in future research. In addition, higher resolution and/or more accurate chromosomal screening tests could be used in future studies to corroborate the current findings. WIDER IMPLICATIONS OF THE FINDINGS: These findings provide critical insights into the mechanisms causing errors during female meiosis and the preimplantation embryo development period to improve the design and treatment outcome of PGS. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. TRIAL REGISTRATION NUMBER: Not applicable.Human Reproduction 11/2012; · 4.47 Impact Factor -
Article: Array CGH in routine prenatal diagnosis practice: reply letter.
Prenatal Diagnosis 07/2012; 32(7):711-2. · 2.11 Impact Factor -
Article: Introducing array comparative genomic hybridization into routine prenatal diagnosis practice: a prospective study on over 1000 consecutive clinical cases.
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ABSTRACT: To assess the feasibility of offering array-based comparative genomic hybridization testing for prenatal diagnosis as a first-line test, a prospective study was performed, comparing the results achieved from array comparative genomic hybridization (aCGH) with those obtained from conventional karyotype. Women undergoing amniocentesis or chorionic villus sampling were offered aCGH analysis. A total of 1037 prenatal samples were processed in parallel using both aCGH and G-banding for standard karyotyping. Specimen types included amniotic fluid (89.0%), chorionic villus sampling (9.5%) and cultured amniocytes (1.5%). Chromosomal abnormalities were identified in 34 (3.3%) samples; in 9 out of 34 cases (26.5%) aCGH detected pathogenic copy number variations that would not have been found if only a standard karyotype had been performed. aCGH was also able to detect chromosomal mosaicism at as low as a 10% level. There was complete concordance between the conventional karyotyping and aCGH results, except for 2 cases that were only correctly diagnosed by aCGH. This study demonstrates that aCGH represents an improved diagnostic tool for prenatal detection of chromosomal abnormalities. Although larger studies are needed, our results provide further evidence on the feasibility of introducing aCGH as a first-line diagnostic test in routine prenatal diagnosis practice.Prenatal Diagnosis 12/2011; 31(13):1270-82. · 2.11 Impact Factor -
Article: Detection of chromosomal aneuploidies in fetal cells isolated from maternal blood using single-chromosome dual-probe FISH analysis.
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ABSTRACT: Detection of chromosomal aneuploidies using fetal cells isolated from maternal blood, for prenatal non-invasive genetic investigation, has been a long-sought goal of clinical genetics to replace amniocentesis and chorionic villous sampling to avoid any risk to the fetus. The purpose of this study was to develop a sensitive and specific new assay for diagnosing aneuploidy with circulating fetal cells isolated from maternal blood as previously reported using two novel approaches: (i) simultaneous immunocytochemistry (ICC) evaluation using a monoclonal antibody for i-antigen, followed by fluorescence in situ hybridization (FISH); (ii) dual-probe FISH analysis of interphase nuclei using two differently labeled probes, specific for different loci of chromosomes 21 and 18; in addition, short tandem repeats (STR) analysis on single cells isolated by micromanipulation was applied to confirm the presence of fetal cells in the cell sample enriched from maternal blood. Blood samples were obtained from women carrying trisomic fetuses, and from non-pregnant women and men as controls. Using ICC-FISH approach, a large heterogeneity in immunostaining pattern was observed, which is a source of very subjective signal interpretation. Differently, dual-probe FISH analysis provided for a correct diagnosis of all pregnancies: the mean percentage of trisomic cells was 0.5% (range, 0.36-0.76%), while the mean percentage of trisomic cells in the control group (normal pregnancies or non-pregnant women) was ≤0.20%. The application of the dual-probe FISH protocol on fetal cells isolated from maternal blood enables accurate molecular detection of fetal aneuploidy, thus providing a foundation for development of non-invasive prenatal diagnostic testing.Clinical Genetics 09/2011; 82(2):131-9. · 3.13 Impact Factor -
Article: Genome profiling of ovarian adenocarcinomas using pangenomic BACs microarray comparative genomic hybridization.
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ABSTRACT: Routine cytogenetic investigations for ovarian cancers are limited by culture failure and poor growth of cancer cells compared to normal cells. Fluorescence in situ Hybridization (FISH) application or classical comparative genome hybridization techniques are also have their own limitations in detecting genome imbalance especially for small changes that are not known ahead of time and for which FISH probes could not be thus designed. We applied microarray comparative genomic hybridization (A-CGH) using one mega base BAC arrays to investigate chromosomal disorders in ovarian adenocarcinoma in patients with familial history. Our data on 10 cases of ovarian cancer revealed losses of 6q (4 cases mainly mosaic loss), 9p (4 cases), 10q (3 cases), 21q (3 cases), 22q (4 cases) with association to a monosomy X and gains of 8q and 9q (occurring together in 8 cases) and gain of 12p. There were other abnormalities such as loss of 17p that were noted in two profiles of the studied cases. Total or mosaic segmental gain of 2p, 3q, 4q, 7q and 13q were also observed. Seven of 10 patients were investigated by FISH to control array CGH results. The FISH data showed a concordance between the 2 methods. The data suggest that A-CGH detects unique and common abnormalities with certain exceptions such as tetraploidy and balanced translocation, which may lead to understanding progression of genetic changes as well as aid in early diagnosis and have an impact on therapy and prognosis.Molecular Cytogenetics 02/2008; 1:10. -
Article: Diagnostic evaluation of women experiencing repeated in vitro fertilization failure.
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ABSTRACT: The aim of the study was to propose a set of tests to clarify the diagnosis of repeated implantation failure in patients undergoing in vitro fertilization (IVF). Fifty-nine patients with at least two unsuccessful IVF attempts were included in the study. Blood samples were evaluated for the presence of underlying thyroid abnormalities, antiphospholipid antibodies (aPL), increased levels of natural killer cells (NK), inherited thrombophilia and mouse embryo assay factor (MEA-f). The same tests were performed on 20 normal fertile control patients. Seventy-six percent of IVF patients showed at least one abnormal result. This incidence was higher with respect to that found among control patients (45%). The prevalence of thyroid abnormalities, aPL and increased NK level was higher in IVF patients whereas no differences were observed in terms of prevalence of inherited thrombophilias and MEA-f. A better understanding of reproductive failure mechanisms should allow an effective diagnostic flow chart and a focused therapeutic option for patients experiencing repeated IVF failure. With this objective in mind, our data provide two important results: thyroid abnormalities, aPL and increased NK levels are more prevalent in women experiencing IVF failure. No evidence was found for an association between inherited thrombophilia and MEA-f and failure to achieve pregnancy after IVF.European Journal of Obstetrics & Gynecology and Reproductive Biology 04/2006; 125(1):79-84. · 1.97 Impact Factor -
Article: Short tandem repeats haplotyping of the HLA region in preimplantation HLA matching.
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ABSTRACT: Recently, preimplantation genetic diagnosis (PGD) has been considered for several indications beyond its original purpose, not only to test embryos for genetic disease but also to select embryos for a nondisease trait, such as specific human leukocyte antigen (HLA) genotypes, related to immune compatibility with an existing affected child in need of a haematopoetic stem cell (HSC) transplant. We have optimized an indirect single-cell HLA typing protocol based on a multiplex fluorescent polymerase chain reaction (PCR) of short tandem repeat (STR) markers scattered throughout the HLA complex. The assay was clinically applied in 60 cycles from 45 couples. A conclusive HLA-matching diagnosis was achieved in 483/530 (91.1%) of the embryos tested. In total, 74 (15.3%) embryos revealed an HLA match with the affected siblings, 55 (11.4%) of which resulted unaffected and 46 (9.5%) have been transferred to the patients. Nine pregnancies were achieved, five healthy HLA-matched children have already been delivered and cord blood HSCs, were transplanted to three affected siblings, resulting in a successful haematopoietic reconstruction.European Journal of HumanGenetics 09/2005; 13(8):953-8. · 4.40 Impact Factor -
Article: The use of non-physiological conditions to isolate fetal cells from maternal blood.
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ABSTRACT: Fetal cells are always present in maternal blood starting in the first trimester of pregnancy, however a rapid, simple, and consistent procedure for their isolation for prenatal non-invasive genetic investigation is still lacking. Sensitivity and recovery of fetal cells is jeopardized by the minute amount of circulating fetal cells and their loss during the enrichment procedure. We report here a single-step approach to isolate fetal cells from maternal blood which relies on the use of non-physiological conditions to modify cell densities before their separation in a density gradient and in a newly developed cell separation device. Isolated fetal cells have been investigated using cytochemistry, Soret band absorption microscopy, monoclonal antibodies for epsilon- and gamma-chain-Hb, monoclonal antibody for i-antigen, and by fluorescence in situ hybridization (FISH). Fetal cells were always detected in all 105 maternal blood samples investigated and fetal aneuploidies were correctly diagnosed by FISH, in a pilot study of pathological pregnancies, in fetal cells isolated from maternal blood obtained either before or after invasive procedure.Experimental Cell Research 02/2005; 302(2):153-61. · 3.58 Impact Factor
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2011–2012
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GENOMA Molecular Genetics Laboratory
Roma, Latium, Italy
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