• Journal of Genetic Medicine
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• v.2 no.2
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• pp.71-77
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• 1998

Comparative genomic hybridization (CGH) can now be applied to detect the origin of extra or missing chromosomal material in cases with common unbalanced aberrations and in prenatal investigations. This method has been used in 13 cases of fetal samples for this study; 3 for amniocytes, 2 for cord blood and 8 for abortus tissues. These samples were previously subjected to GTG-banding. Our study showed aneuploidy in 8 cases, and partial monosomy, partial trisomy or marker chromosome in the remaining 5. The CGH disclosed further small genetic imbalances in 4 of all 13 cases: a prenatal sample showing del(20)(q13) by GTG confirmed a loss of the segment 20p13-pter by CGH; a marker chromosome manifested normal CGH profile; chromosome der(?)(?;15) found in an abortus sample by GTG turned out to be a loss of 15pter-q14 (partial monosomy) and a gain of 10pter-q22 (partial trisomy); the der(15) shown by GTG represented partial trisomy of 3q24-qter. These findings show that CGH is very useful and efficient for cytogenetic investigations of clinical cases.

• Journal of Genetic Medicine
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• v.13 no.2
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• pp.95-98
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• 2016

We report the prenatal diagnosis of an unbalanced translocation between chromosome Y and chromosome 15 in a female fetus. Cytogenetic analysis of parental chromosomes revealed that the mother had a normal 46,XX karyotype, whereas the father exhibited a 46,XY,der(15)t(Y;15) karyotype. We performed cytogenetic analysis of the father's family as a result of the father and confirmed the same karyotype in his mother and brother. Fluorescence in situ hybridization and quantitative fluorescent-polymerase chain reaction analysis identified the breakpoint and demonstrated the absence of the SRY gene in female members. Thus, the proband inherited this translocation from the father and grandmother. This makes the prediction of the fetal phenotype possible through assessing the grandmother. Therefore, we suggest that conventional cytogenetic and molecular cytogenetic methods, in combination with family history, provide informative results for prenatal diagnosis and prenatal genetic counseling.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.393-398
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• 1997

Cytogenetic analysis was performed in 1321 couples and 141 women with history of abnormal reproductive outcome during 1988-1996. The use of high resolution banding technique and fluorescence in situ hybridization (FISH) in the chromosome analysis has made the precise evaluation of chromosome aberrations. The prevalence of balanced chromosomal translocation carriers were 3.74% (104/2783 patients). 70 cases (2.52%) were reciprocal translocation carriers and 34 (1.22%) had Robertsonian translocations. Chromosome aberrations were more frequent in women (73 cases) than in men (31 cases). No phenotypical abnormalities were found in all carriers, but they experienced abnormal reproductive outcomes such as recurrent spontaneous abortions, anomalous offsprings or infertility problem. Prenatal diagnosis was carried out on 36 subsequent pregnancies in balanced translocation carriers. The fetal karyotypes showed that 12 cases (33%) were normal, 22 (61%) were balanced translocations, and two (6%) were unbalanced translocations. It is concluded that the prevalence of balanced chromosomal translocations in patients with abnormal reproductive outcome is higher than that of the normal population. Most of the fetal samples showed normal karyotypes or balanced translocations. Although the incidence of chromosomal imbalance in the fetuses was relatively low in prenatal diagnosis, individuals with balanced translocations are predisposed to abnormal offspring with partial trisomy or monosomy. Therefore we recommend that genetic counselling and cytogenetic prenatal diagnosis for translocation carriers have to be offered to prevent recurrent chromosomal abnormal babies.

• Journal of Genetic Medicine
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• v.2 no.2
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• pp.59-63
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• 1998

Between 1988-1998, cytogenetic analyses were performed for 1,476 couples and 162 women with recurrent abortions. We applied GTG-banding, high resolution-banding and FISH (fluorescent in situ hybridization) techniques in this study. The frequency of balanced translocations was 3.6% (112/3114). Of them, 74 cases (2.38%) were reciprocal translocations and 38 (1.22%) were robertsonian translocations. Chromosome aberrations were more frequent in women (80 cases) than in men (32 cases). No phenotypical abnormalities were found in all carriers who had experienced recurrent spontaneous abortions or experienced giving birth to malformed offsprings. Prenatal cytogenetic analyses were carried out on 40 subsequent pregnancies for carrier couples with balanced translocation. The fetal karyotypes showed that 13 cases (32.5%) were normal, 25 (62.5%) were balanced translocations, and two (6%) were unbalanced translocations. It is believed that the frequency of chromosomal abnormalities in patients with recurrent spontaneous abortion is higher than that of the normal population. Most of the fetal samples showed normal karyotypes or balanced translocations matching that of one of their parents. Although the incidence of chromosomal imbalance in the fetuses was relatively low in prenatal cytogenetic analysis, individuals with balanced translocations are predisposed to giving birth to malformed offsprings with partial trisomy or monosomy. Therefore, we recommend the cytogenetic and the prenatal cytogenetic analysis for those who experiences recurrent abortion as well as in case they become pregnant, to prevent the birth of offsprings with chromosomal abnormalities.