Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Intervalo de ano de publicação
8.
J Assist Reprod Genet ; 38(8): 2183-2192, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33742344

RESUMO

PURPOSE: To verify which genetic abnormalities prevent embryos to blastulate in a stage-specific time. METHODS: A single center retrospective study was performed between April 2016 and January 2017. Patients requiring Preimplantation Genetic Testing for Aneuploidies (PGT-A) by Next Generation Sequencing (NGS) were included. All embryos were cultured in a time-lapse imaging system and single blastomere biopsy was performed on day 3 of development. Segmental duplications and deletions as well as whole chromosome monosomies and trisomies were registered. Embryo arrest was defined if the embryo failed to blastulate 118 h post-injection. A logistic regression model was applied using the time to blastulate as the response variable and the different mutations as explanatory variables. A p value < 0.05 was considered significant. RESULTS: Of the 285 biopsied cleavage stage embryos, 103 (36.1%) were euploid, and 182 (63.9%) were aneuploid. There was a significant difference in the developmental arrest between euploid and aneuploid embryos (8.7% versus 42.9%; p = 0.0001). Segmental duplications and whole chromosome monosomies were found to have a significant effect on developmental arrest (p = 0.0163 and p = 0.0075), while trisomies and segmental deletions had no effect on developmental arrest. In case of segmental duplications, an increase of one extra segmental duplication increases the odd of arrest by 159%. For whole chromosome monosomies, the odd will only increase by 29% for every extra chromosomal monosomy. Both chromosomal abnormalities remained significant after adding age as an explanatory variable to the model (p = 0.014 and p = 0.009). CONCLUSION: Day 3 cleavage stage embryos with segmental duplications or monosomies have a significantly decreased chance to reach the blastocyst stage.


Assuntos
Aneuploidia , Blastocisto/patologia , Implantação do Embrião , Fertilização in vitro/estatística & dados numéricos , Monossomia , Diagnóstico Pré-Implantação/métodos , Duplicações Segmentares Genômicas , Adulto , Feminino , Testes Genéticos , Humanos , Gravidez , Estudos Retrospectivos
9.
Hum Reprod ; 34(6): 998-1010, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31114858

RESUMO

STUDY QUESTION: How reliable are cleavage stage and trophectoderm (TE) biopsies compared to inner cell mass (ICM) biopsies? SUMMARY ANSWER: The reliability of TE biopsy compared to ICM biopsy is almost perfect, but only substantial between cleavage stage biopsy and ICM biopsy. WHAT IS KNOWN ALREADY: One of the prevailing reasons for implantation failure is presumed to be chromosomal aneuploidy in human preimplantation embryos. Preimplantation genetic testing for aneuploidies (PGT-A) has been introduced into assisted reproduction in an effort to increase pregnancy rates. Increasing evidence indicates that genetic results obtained following blastomere or TEbiopsy may not accurately reflect the true genetic status of the embryo due to the presence of embryonic mosaicism, and therefore the reliability of PGT is highly controversial. STUDY DESIGN, SIZE, DURATION: This was an observational descriptive study, performed in a private infertility centre from August 2016 to January 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: The mean female age was 33.9 years, ranging from 24 to 46 years, and the mean number of biopsied embryos per couple was 2.2 (range 1-7 embryos). Blastomere biopsies had been performed at cleavage stage on Day 3 (D3) due to the turnover time of genetic testing and the inability to cryopreserve embryos in accordance with the local law governing ART. To confirm the genetic results in embryos not chosen for transfer, additional biopsies of the TE at blastocyst stage (BLASTO-TE) as well as of the ICM (BLASTO-ICM) were performed on D5. Only surplus blastocysts, which had not been selected for transfer and were not cryopreserved in accordance with the law governing ART, had been included. MAIN RESULTS AND THE ROLE OF CHANCE: Comparison of all biopsies (D3/BLASTO-ICM/BLASTO-TE) per embryo demonstrated that 50 (59.5%) out of 84 embryos showed concordance in all three results (= full concordance). Thirty-four (40.4%) embryos had at least two discordant results between the three biopsies, regardless of whether the embryo diagnosis (aneuploid/euploid) was discordant or not, or in aneuploid embryos, whether the chromosomal patterns were inconsistent. Nine (= 10.7%) embryos had complete discordance between all three biopsies. False positive results between D3/BLASTO-TE, D3/BLASTO-ICM and BLASTO-TE/BLASTO-ICM were 26.4%/30.2% and 7.5%, respectively, while the Kappa agreement between the different approaches was 0.647, 0.553 and 0.857, respectively. Therefore the reliability of D3/BLASTO-TE, D3/BLASTO-ICM and BLASTO-TE/BLASTO-ICM can be interpreted as substantial, as moderate and as almost perfect. LIMITATIONS, REASONS FOR CAUTION: The limitation of this study is the possible bias in the concordance/discordance rate because embryos that had been selected for transfer did not undergo biopsy on D5. WIDER IMPLICATIONS OF THE FINDINGS: The obvious discordance between the three different approaches for PGT-A underlines the limitations of genetic testing and highlights the importance of ongoing research in order to improve the accuracy of PGT-A results. Until then reproductive specialists will continue to make challenging decisions on whether to transfer or discard an embryo in light of current evidence questioning the reliability of genetic results. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by Igenomix. The funder provided support in the form of salary for R.C. The co-author R.C. is an employee of Igenomix. She participated in the blinded analysis of the samples; however the final data collection and statistical analysis of the results, as well as the decision to publish, was taken by B.L, I.E. and H.F. The authors B.L., I.E., A.L., A.B., A.A., N.D. and H.F. have no competing interests. The funder did not have any additional role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. The commercial affiliation of R.C. did not play any role in the study. TRIAL REGISTRATION NUMBER: This study was approved by the Ethics Committee of IVIRMA Middle East Fertility Clinic, Abu Dhabi, UAE (Research Ethics Committee IVI-MEREFA009a/2017).


Assuntos
Massa Celular Interna do Blastocisto/patologia , Testes Genéticos/métodos , Mosaicismo , Diagnóstico Pré-Implantação/métodos , Trofoblastos/patologia , Adulto , Biópsia , Implantação do Embrião , Transferência Embrionária/métodos , Feminino , Humanos , Infertilidade/terapia , Pessoa de Meia-Idade , Gravidez , Reprodutibilidade dos Testes , Tempo para Engravidar , Adulto Jovem
10.
Forensic Sci Int Genet ; 32: 18-25, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29024923

RESUMO

A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low FST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents.


Assuntos
Genética Populacional , Mutação INDEL , Polimorfismo de Nucleotídeo Único , Grupos Raciais/genética , Impressões Digitais de DNA , Bases de Dados de Ácidos Nucleicos , Etnicidade/genética , Frequência do Gene , Genótipo , Humanos , Laboratórios/estatística & dados numéricos , Repetições de Microssatélites
11.
Case Rep Genet ; 2017: 4397434, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28928993

RESUMO

OBJECTIVE: To report the arrest of euploid embryos with high mtDNA content. DESIGN: A report of 2 cases. SETTING: Private fertility clinic. PATIENTS: 2 patients, 45 and 40 years old undergoing IVF treatment. INTERVENTIONS: Mature oocytes were collected and vitrified from two ovarian stimulations. Postthaw, survived mature oocytes underwent fertilization by intracytoplasmic sperm injection (ICSI). Preimplantation genetic screening (PGS) and mitochondrial DNA (mtDNA) copy number were done using next generation sequencing (NGS). The only normal embryo among the all-biopsied embryos had the highest "Mitoscore" value and was the only arrested embryo in both cases. Therefore, the embryo transfer was cancelled. MAIN OUTCOME MEASURES: Postthaw survival and fertilization rate, embryo euploidy, mtDNA copy number, and embryo development. RESULTS: In both patients, after PGS only 1 embryo was euploid. Both embryos had the highest mtDNA copy number from all tested embryos and both embryos were arrested on further development. CONCLUSIONS: These cases clearly demonstrate the lack of correlation between mtDNA value (Mitoscore) and chromosomal status of embryo.

12.
Arch Soc Esp Oftalmol ; 92(2): 82-85, 2017 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27268701

RESUMO

CASE REPORT: We report a case of primary small-cell lymphocytic lacrimal gland lymphoma in a male diagnosed with primary antiphospholipid syndrome. These rare lymphomas are usually presented in the clinic as disseminations secondary to chronic lymphocytic leukaemia, and the primary site is rare in the orbit. DISCUSSION: Non-Hodgkin lymphomas are a heterogeneous group of tumours. Although treatment in the IE stage is usually radiotherapy, due to its association with antiphospholipid syndrome, systemic treatment with rituximab was administered.


Assuntos
Neoplasias Oculares/patologia , Aparelho Lacrimal/patologia , Leucemia Linfocítica Crônica de Células B/patologia , Síndrome Antifosfolipídica/complicações , Biópsia , Neoplasias Oculares/complicações , Neoplasias Oculares/diagnóstico por imagem , Neoplasias Oculares/tratamento farmacológico , Humanos , Cadeias kappa de Imunoglobulina/análise , Imunofenotipagem , Imunoterapia , Aparelho Lacrimal/diagnóstico por imagem , Leucemia Linfocítica Crônica de Células B/complicações , Leucemia Linfocítica Crônica de Células B/diagnóstico por imagem , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Rituximab/uso terapêutico , Tomografia Computadorizada por Raios X
13.
Hum Reprod ; 27(7): 1922-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22537817

RESUMO

BACKGROUND: The aneuploidy rate is higher in poor-quality sperm samples, which also have higher DNA fragmentation index values. The aim of this study was to assess the relationship between sperm DNA fragmentation in samples from infertile men belonging to couples with recurrent miscarriage or implantation failure and the aneuploidy rate in spermatozoa as well as in embryos from patients. METHODS: This prospective study evaluated DNA damage and the aneuploidy rate in fresh and processed (density gradient centrifugation) ejaculated sperm as well as the aneuploidy rate in biopsied embryos from fertility cycles. Fluorescence in situ hybridization was used for the aneuploidy analysis. Results were compared using linear regression and analysis of variance. RESULTS: A total of 154 embryos were evaluated from 38 patients undergoing PGD cycles; 35.2% of the embryos were chromosomally normal. Analysis of the same sperm samples showed an increased DNA fragmentation after sperm preparation in 76% of the patients. There was no correlation between DNA fragmentation and the aneuploidy rate in embryos or in fresh or processed sperm samples. CONCLUSIONS: Sperm DNA fragmentation is not related to chromosomal anomalies in embryos from patients with recurrent miscarriage or implantation failure. However, we cannot rule out the possibility that a relationship between DNA fragmentation and aneuploidy exists for other causes of infertility. Furthermore, the different methods used to evaluate DNA fragmentation may produce different results.


Assuntos
Aborto Habitual/genética , Aneuploidia , Fragmentação do DNA , Espermatozoides/patologia , Adulto , Centrifugação com Gradiente de Concentração , Dano ao DNA , Implantação do Embrião , Feminino , Fertilização in vitro , Humanos , Hibridização in Situ Fluorescente , Infertilidade Masculina/genética , Masculino , Idade Materna , Oócitos/citologia , Indução da Ovulação , Idade Paterna , Projetos de Pesquisa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...