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Chromosomal investigation in foetuses with developmental abnormalities
Štolfa, Miroslav ; Novotná, Drahuše (advisor) ; Král, Jiří (referee)
Chromosomal aberrations are common causes of abnormal development of fetuses leading to the birth of malformed indvidual or to the intrauterine death. Half of miscarriages in the first trimester and a third in the second trimester are caused by fetal chromosomal abnormalities, mainly aneuploidies. If fetus is abnormally developed, invasive prenatal cytogenetic diagnosis should be recommended. Positive cytogenetic finding can be reason for induced abortion till the end of 24th week of gestation. We investigated 81 miscarriages, 46 fetuses from induced abortions and 80 fetuses with abnormal development from ongoing pregnancies. G-banding analysis was used as the main method for investigating miscarriages. Genomic DNA isolated from abnormally developed fetuses was screened by array CGH technique. We found 43,75 % chromosomal abnormal miscarried fetuses, majority of them with numerical aberrations (91,4 %). In group of induced abortions, 25,71 % fetuses carried chromosomal abnormality. The lowest rate 11,67 % of chromosoal aberrations was detected in group of prenatally diagnosed fetuses from ongoing pregnancies. Array CGH detected submicroscopic aberrations in 13,41 % fetuses with ultrasound findings. All together 25,74 % microscopic and causal submicroscopic chromosomal abnormalities were found to be...
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Analysis of mosaic chromosomal aberrations using various methods
Oroszová, Karin ; Drábová, Jana (advisor) ; Šolc, Roman (referee)
Mosaicism is represented by two or more chromosomally different cell lines in an individual. Mosaics are most often caused by chromosome malsegregation during mitosis, resulting in the gain or loss of chromosomes, known as aneuploidy, but structural aberrations can also occur in mosaic form. The problem is the limitation of detection with standart cytogenetic methods. The present study was carried out to compare the efficiency of FISH, array CGH and cytogenetic techniques in detection of mosaicism. In the practical part the results of 45 patients with mosaicisms of aneuplody of gonosomes (26 patients) and mosaicisms of autosomes (19 patients) were compared. The data show that we have different peripheral blood karyotype and FISH results in 23 of 37 patients (62%). There was a case of failure of detection of the mosaicism on the karyotype and the FISH method revealed a abnormal cell lines with a percentage of less than 5%. The array CGH method confirmed the karyotype and FISH results in 10 out of 12 patients (83%) in peripheral blood tests. The work also dealt with artificially made mosaics. From the results, it is obvious that the FISH method has a more accurate percentage of mosaic capture compared to the karyotype. The results indicate that using the techniques in parallel allow in clinical...
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Application of cytogenetic and molecular cytogenetic methods in prenatal diagnosis
Rašpličková, Tereza ; Novotná, Drahuše (advisor) ; Zemanová, Zuzana (referee)
Foetal anomalies found on ultrasound increase the probability of occurrence of chromosomal abnormalities. They cause about one quarter of all abortions and stillbirths and many of inborn defects in newborns. Karyotype analysis is number one method in prenatal diagnosis whereas array CGH is often used as a verification and supplemental method. The aim of this work was to prove that array CGH gives additional chromosomal findings to karyotypes and could substitute conventional karyotyping as a primary examination method in foetuses with ultrasound findings. We examined 45 prenatal samples using both methods. These samples were referred for invasive examination because of abnormal ultrasound findings. Karyotype analyses found two abnormalities in two (4,4 %) patients and array CGH identified aberrations in five (11,1 %) foetuses whereas both anomalies detected by karyotypes were discovered by array CGH too. This means that array CGH identified about 6,7 % more aberrations than karyotype. Our results correspond with scientific articles which refer that array CGH should replace karyotype not only in postnatal examinations but even in prenatal diagnosis. Keywords: chromosomal aberrations, array CGH, karyotype, prenatal diagnosis, ultrasound
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Chromosomal investigation in foetuses with developmental abnormalities
Štolfa, Miroslav ; Novotná, Drahuše (advisor) ; Král, Jiří (referee)
Chromosomal aberrations are common causes of abnormal development of fetuses leading to the birth of malformed indvidual or to the intrauterine death. Half of miscarriages in the first trimester and a third in the second trimester are caused by fetal chromosomal abnormalities, mainly aneuploidies. If fetus is abnormally developed, invasive prenatal cytogenetic diagnosis should be recommended. Positive cytogenetic finding can be reason for induced abortion till the end of 24th week of gestation. We investigated 81 miscarriages, 46 fetuses from induced abortions and 80 fetuses with abnormal development from ongoing pregnancies. G-banding analysis was used as the main method for investigating miscarriages. Genomic DNA isolated from abnormally developed fetuses was screened by array CGH technique. We found 43,75 % chromosomal abnormal miscarried fetuses, majority of them with numerical aberrations (91,4 %). In group of induced abortions, 25,71 % fetuses carried chromosomal abnormality. The lowest rate 11,67 % of chromosoal aberrations was detected in group of prenatally diagnosed fetuses from ongoing pregnancies. Array CGH detected submicroscopic aberrations in 13,41 % fetuses with ultrasound findings. All together 25,74 % microscopic and causal submicroscopic chromosomal abnormalities were found to be...
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