Percorrer por autor "Caetano, Paula"
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- Discordant Chromosome Placental Mosaicism in a Dichorionic Twin PregnancyPublication . Silva, Marisa; Caetano, Paula; Olival, Vanessa; Alves, Cristina; Simao, Laurentino; Ferreira, Cristina; Marques, Bárbara; Furtado, José; Ventura, Catarina; Soares, Sérgio; Correia, Hildeberto
- Gestações gemelares: anomalias cromossómicas em diagnóstico pré-natal (2001-2012)Publication . Brito, Filomena; Simão, Laurentino; Alves, Ana; Silva, Marisa; Furtado, José; Ventura, Catarina; Ambrósio, Paula; Geraldes, Céu; Melo, Antonieta; Correia, Joaquim; Antunes, Diana; Caetano, Paula; Correia, HildebertoIntrodução: As gestações gemelares (GG) têm aumentado significativamente nos últimos anos, sendo este aumento atribuído a um efeito combinado de tratamentos de fertilidade e aumento da idade materna. As grávidas com GG têm um risco acrescido de anomalias cromossómicas fetais, comparativamente às de gestações simples. Objetivo: Avaliação dos resultados obtidos em estudos de Diagnóstico Pré-Natal (DPN) de Anomalias Cromossómicas em gestações gemelares, na Unidade de Citogenética (UCI) do Departamento de Genética Humana do Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, no período de Janeiro de 2001 a Junho de 2012. Material e Métodos: Analisaram-se retrospetivamente casos de GG que efetuaram DPN de anomalias cromossómicas no período considerado. Foram analisados os parâmetros: classificação da gestação, indicação clinica, idade materna, semanas de gestação e resultado do estudo citogenético. Resultados: Num total de 7792 amostras pré-natais analisadas foram consideradas 340, correspondendo a 172 GG. As indicações clínicas mais frequentes foram idade materna (89/172=51.7%) e alterações ecográficas em pelo menos um dos fetos (42/172=24.4%). A idade média das grávidas e do tempo de gestação foi de 34.3 anos e 17.7 semanas respetivamente. Foram detetados 8 cariotipos com alterações cromossómicas, correspondendo a 4.7% das GG. Nas gestações simples a taxa de anomalias cromossómicas observada foi de 5.3% (398/7452). Conclusão: A taxa de anomalias cromossómicas observada nas GG é inferior à observada nas gestações simples no mesmo período de tempo e tipo de amostragem, não correspondendo ao esperado. A taxa de anomalias cromossómicas detetada no total das gestações foi sobreponível aos valores reportados pela DGS.
- Prenatal diagnosis of terminal 11q deletionPublication . Simão, Laurentino; Brito, Filomena; Silva, Marisa; Marques, Bárbara; Furtado, José; Ventura, Catarina; Caetano, Paula; Dias, Ivone; Correia, HildebertoThe majority of 11q deletion cases described may be included in the “distal 11q deletion syndrome”, or Jacobsen syndrome. This is a rare but clinically recognizable condition with an incidence of 1/ 100,000 births. The most common clinical features are psychomotor delay, characteristic facial dysmorphism and malformations of the heart, kidney, genitalia, central nervous system and skeleton. Patients usually have visible deletions of chromosomal bands 11q23, 11q24, and/or 11q25. Approximately 85% of the cases are de novo deletions, and only a few prenatal cases have been reported. We report the clinical case of a 30-year-old pregnant woman who was referred to our laboratory with a positive first trimester prenatal screening for Down syndrome. The cytogenetic analysis revealed a terminal deletion on the distal 11q chromosome. Fluorescence in situ hybridization using a whole-chromosome painting probe and subtelomeric probes confirmed the terminal deletion and excluded other material involvement. Parental karyotypes were normal. Second trimester ultrasound revealed clinodactyly and a cardiac defect described as a subvalvular and intraventricular communication. The couple opted for medical termination of pregnancy. The postmortem examination of the 22-week fetus showed facial dysmorphism, cardiac defects and uterus bicornis. There are few reports of prenatally diagnosed 11q−,and there seems to be a phenotypic variability. Some cases had a positive prenatal screening for Down syndrome and/or abnormal prenatal ultrasound with olygohydramnios, nuchal thickening, heart malformations and kidney anomalies. Other reports mention no structural fetal abnormalities. The present case, similar to others, had a positive first trimester screening. The fetus presented abnormal fingers, cardiac defects and malformations of genital tract, identified at the second trimester, which is consistent with the del11q− phenotype. This case reinforces the phenotypic variability associated with partial monosomy of distal 11q in the fetus and the difficulty of establishing genotype–phenotype correlations.
- Prenatal Investigation of a Familial Partial Monosomy 10qPublication . Silva, Marisa; Marques, Bárbara; Brito, Filomena; Ferreira, Cristina; Furtado, José; Ventura, Catarina; Nunes, Luis; Kay, Teresa; Caetano, Paula; Correia, HildebertoObjective: To present the clinical, cytogenetic and molecular findings of a prenatal study of a familial partial monosomy 10q. Distal 10q deletions are rare and the majority are terminal deletions involving bands 10q25 and 10q26. Patients typically present with facial dysmorphism, postnatal growth retardation, developmental and mental retardation, genitourinary anomalies and digital anomalies. Methods: Conventional cytogenetic analysis in metaphases obtained by chorionic villi long term cultures, multiplex ligation dependent probe amplification (MLPA), fluorescent in situ hybridization (FISH), microarray analysis. Results: A 24-year-old gravida was referred for chorionic villus sampling at 12+6 weeks of gestation due to a previous child with facial dysmorphism, bilateral inguinal hernia, short stature and mild to moderate psychomotor delay of whom a microarray analysis was underway. His karyotype was normal but array-CGH analysis disclosed a 10q24.33-q25.1 interstitial deletion. The deletion encompasses 987Kb to 1,14Mb and includes 20 genes, in particular the COL17A gene. Fetal and parental karyotypes were normal. FISH analysis with a BAC clone located within the 10q region deleted in the phenotypically abnormal sibling showed normal results for both the mother and the fetus and a deletion in the apparently normal father. Conclusion: In this case chorionic villi analysis as well as the application of FISH with a specific and targeted BAC clone allowed a shorter turnaround time for the prenatal investigation of the chromosomal abnormality. The authors discuss the challenges of microarray analysis application in the prenatal setting namely in cases like the one presented here where there seems to be phenotypic variability.
- A retrospective study of Down syndrome in prenatal diagnosis. Did chorionic villus sampling allow a better prevention?Publication . Simão, Laurentino; Silva, Marisa; Brito, Filomena; Alves, Cristina; Marques, Bárbara; Ferreira, Cristina; Ambrósio, Paula; Silva, Maria do Céu; Ventura, Catarina; Duarte, Guida; Caetano, Paula; Correia, Joaquim; Melo, AntonietaIntroduction Down syndrome (DS) is the most common single genetic cause of human moderate mental retardation, with an estimated prevalence of 9.2 cases per 10,000 live births. We aimed at analyzing changes in prenatal diagnosis (PND) over time, namely the referral reasons for chromosome analyses and the introduction of chorionic villus sampling (CVS), and its influence on the results obtained in DS cases. Methods We retrospectively evaluated the PND results from samples analyzed between 1987 and 2011 (25 years) in our cytogenetic laboratory taking into account the referral reasons, type of sample, karyotype and reporting time. Results 263 fetuses with a karyotype compatible with DS were identified in a total of 18,107 karyotypes (1.5%). The highest frequencies of DS were found among cases referred because of ultrasonography findigs (namely increased nuchal translucency) or positive first trimester screening and when one parent carries a chromosomal rearrangement. The frequency of recurrence was found to be 1/72. The increasing use of CVS led to an earlier response in terms of gestational age (mean at diagnosis- 13+4 weeks). In addition, an increased percentage of karyotypes with SD was detected (8.4% of CVS samples). On the other hand, implementation of molecular rapid aneuploidy detection in part of the samples allowed a better report time in DS cases, from 23 days in 1987 to 2 days in 2011. Discussion DS detection remains the most important reason for performing PND. The collecting of CVS has been rising over the last years, which has resulted in an increased number of trisomy 21 cases identified in a lower gestational age, allowing a better karyotype-phenotype correlation in earlier pregnancies. Moreover, the use of complementary molecular techniques for the detection of common aneuploidies reduced the mean reporting time and allowed an earlier decision of the couple concerning the future of gestation.