Prenatal diagnosis--principles of diagnostic procedures and genetic counseling.

Department of Genetics, Wroclaw Medical University, Poland.
Folia Histochemica et Cytobiologica (Impact Factor: 1). 02/2007; 45 Suppl 1:S11-6.
Source: PubMed

ABSTRACT The frequency of inherited malformations as well as genetic disorders in newborns account for around 3-5%. These frequency is much higher in early stages of pregnancy, because serious malformations and genetic disorders usually lead to spontaneous abortion. Prenatal diagnosis allowed identification of malformations and/or some genetic syndromes in fetuses during the first trimester of pregnancy. Thereafter, taking into account the severity of the disorders the decision should be taken in regard of subsequent course of the pregnancy taking into account a possibilities of treatment, parent's acceptation of a handicapped child but also, in some cases the possibility of termination of the pregnancy. In prenatal testing, both screening and diagnostic procedures are included. Screening procedures such as first and second trimester biochemical and/or ultrasound screening, first trimester combined ultrasound/biochemical screening and integrated screening should be widely offered to pregnant women. However, interpretation of screening results requires awareness of both sensitivity and predictive value of these procedures. In prenatal diagnosis ultrasound/MRI searching as well as genetic procedures are offered to pregnant women. A variety of approaches for genetic prenatal analyses are now available, including preimplantation diagnosis, chorion villi sampling, amniocentesis, fetal blood sampling as well as promising experimental procedures (e.g. fetal cell and DNA isolation from maternal blood). An incredible progress in genetic methods opened new possibilities for valuable genetic diagnosis. Although karyotyping is widely accepted as golden standard, the discussion is ongoing throughout Europe concerning shifting to new genetic techniques which allow obtaining rapid results in prenatal diagnosis of aneuploidy (e.g. RAPID-FISH, MLPA, quantitative PCR).

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    ABSTRACT: Objective: The aim of this study was presentation of the ultrasonographic findings and perinatal autopsy of cases with rare chromosomal abnormalities. Material and Method: A total of 10125 prenatal cases over 17 years including 8731 amniocentesis, 973 chorionic villus sampling, and 421 fetal blood sampling cases were evaluated for prenatal cytogenetic diagnosis. Conventional cytogenetic studies, fluorescence in situ hybridization studies, and Array-CGH analysis techniques were used for genetic analysis. Results: A structural chromosomal abnormality was observed in 95 cases. The most frequently observed structural abnormalities were balanced translocations with a frequency of 53.7% (51 cases) followed by unbalanced translocations (16.8%), inversions (11.6%), supernumerary marker chromosomes (8.4%), duplications (4.2%), deletions and ring chromosomes (2.1%) and complex translocation (1.1%). Rare structural chromosomal abnormalities including de novo balanced translocations, unbalanced translocations, inversions, duplications, deletions, ring chromosomes, and supernumerary marker chromosomes were detected in 24 cases. Conclusion: The rate of rare chromosomal abnormalities varies from 2.4% (South East Ireland) to 12.9% (Northern England) in Europe with a total rate of 7.4/10 000 births. In our study, the overall rate of chromosomal abnormality in prenatal cytogenetic diagnosis was 3.7%, similar to South East Ireland. Ultrasonographic and perinatal autopsy findings of the cases with rare structural chromosomal abnormalities are important for proper genetic counseling for further similar cases.
    Turk Patoloji Dergisi 10/2014; DOI:10.5146/tjpath.2014.01280
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    ABSTRACT: The presence of unique copy number variations (CNVs) in miscarriages suggests that their integral genes have a role in maintaining early pregnancy. In our previous work, we identified 19 unique CNVs in ~40% of studied euploid miscarriages, which were predominantly familial in origin. In our current work, we assessed their relevance to miscarriage by expression analysis of 14 genes integral to CNVs in available miscarriage chorionic villi. As familial CNVs could cause miscarriage due to imprinting effect, we investigated the allelic expression of one of the genes (TIMP2) previously suggested to be maternally expressed in placenta and involved in placental remodelling and embryo development. Six out of fourteen genes had detectable expression in villi and for three genes the RNA and protein expression was altered due to maternal CNVs. These genes were integral to duplication on Xp22.2 (TRAPPC2 and OFD1) or disrupted by a duplication mapping to 17q25.3 (TIMP2). RNA and protein expression was increased for TRAPPC2 and OFD1 and reduced for TIMP2 in carrier miscarriages. The three genes have roles in processes important for pregnancy development such as extracellular matrix homeostasis (TIMP2 and TRAPPC2) and cilia function (OFD1). TIMP2 allelic expression was not affected by the CNV in miscarriages in comparison to control elective terminations. We propose that functional studies of CNVs could help determine if and how the miscarriage CNVs affect the expression of integral genes. In case of parental CNVs, assessment of the function of their integral genes in parental reproductive tissues should be also considered in the future, especially if they affect processes relevant for pregnancy development and support.
    Molecular Cytogenetics 01/2015; 8:6. DOI:10.1186/s13039-015-0109-8 · 2.66 Impact Factor
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    ABSTRACT: Introduction: Karyotyping has been the gold standard for chromosomal analysis in prenatal diagnosis over the past 40 years. However, many articles and the first meta-analysis on the potential advantages of array-CGH (array comparative genomic hybridization) compared to karyotyping in prenatal diagnosis began to appear in 2011.
    Revista colombiana de obstetricia y ginecología 09/2013; 64(3):327-332.

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