• Clinical and Experimental Pediatrics
• /
• v.45 no.7
• /
• pp.917-922
• /
• 2002

An unbalanced translocation is frequently the result of inheritance of an unbalanced haploid set from a parent with a balanced translocation. Families in which one parent is a balanced translocation carrier fall into the following classes : Those in which none of the possible abnormal offsprings is viable; Those in which one type of offspring, usually the one with the smaller deletion, is born alive; Those in which two types of abnormal offspring are viable. We report a neonate whose karyotype was 46,XX,der(2)t(2;7)(q21;p21.2),der(20)t(2;20)(q21;p13). She was small for her gestational age and had multiple anomalies such as exophthalmos, corneal opacity, short neck, tongue tie, clinodactyly, atrial septal defect, patent ductus arteriosus and ventriculomegaly. Moreover, her mother's karyotype was 46,XX,der(2)t(2;7)(q21;p21.2),del(16)(q22.1),der(20)t(2;20)(q21;p13) but her father had normal karyotype. The same derivative chrosomes were found between mother and her infant, except for del(16)(q22.1) in her mother and these same unbalanced translocations in a two-generation family are extremely rare.

• Clinical and Experimental Pediatrics
• /
• v.55 no.3
• /
• pp.107-110
• /
• 2012

Partial trisomy 3p results from either unbalanced translocation or $de$ $novo$ duplication. Common clinical features consist of dysmorphic facial features, congenital heart defects, psychomotor and mental retardation, abnormal muscle tone, and hypoplastic genitalia. In this paper, we report a case of partial trisomy 3p with rare clinical manifestations. A full-term, female newborn was transferred to our clinic. She had cleft lip-plate, dysgenesis of the corpus callosum, patent ductus arteriosus, pulmonary hypertension, and severe right-sided hydronephrosis, associated with ureteropelvic junction obstruction. Cytogenetic investigation revealed partial trisomy 3p; 46,XX,der(4)t(3;4)(p21.1;p16). The karyotype of her father showed a balanced translocation, t(3;4)(p21.1;p16). Therefore, the size of duplication can be an important factor.

• Clinical and Experimental Reproductive Medicine
• /
• v.38 no.3
• /
• pp.126-134
• /
• 2011

Preimplantation genetic diagnosis (PGD) is gradually widely used in prevention of gene diseases and chromosomal abnormalities. Much improvement has been achieved in biopsy technique and molecular diagnosis. Blastocyst biopsy can increase diagnostic accuracy and reduce allele dropout. It is cost-effective and currently plays an important role. Whole genome amplification permits subsequent individual detection of multiple gene loci and screening all 23 pairs of chromosomes. For PGD of chromosomal translocation, fluorescence $in-situ$ hybridization (FISH) is traditionally used, but with technical difficulty. Array comparative genomic hybridization (CGH) can detect translocation and 23 pairs of chromosomes that may replace FISH. Single nucleotide polymorphisms array with haplotyping can further distinguish between normal chromosomes and balanced translocation. PGD may shorten time to conceive and reduce miscarriage for patients with chromosomal translocation. PGD has a potential value for mitochondrial diseases. Preimplantation genetic haplotyping has been applied for unknown mutation sites of single gene disease. Preimplantation genetic screening (PGS) using limited FISH probes in the cleavage-stage embryo did not increase live birth rates for patients with advanced maternal age, unexplained recurrent abortions, and repeated implantation failure. Polar body and blastocyst biopsy may circumvent the problem of mosaicism. PGS using blastocyst biopsy and array CGH is encouraging and merit further studies. Cryopreservation of biopsied blastocysts instead of fresh transfer permits sufficient time for transportation and genetic analysis. Cryopreservation of embryos may avoid ovarian hyperstimulation syndrome and possible suboptimal endometrium.

• Environmental Mutagens and Carcinogens
• /
• v.17 no.1
• /
• pp.12-16
• /
• 1997

Chromosome rearrangement induced by bleomycin were identified by fluorescence in situ hybridization with probe for chromosome 4. The frequency of color junctions, translocations, dicentric and acenttic fragments increased with bleomycin dose. Different types of balanced translocation and dicentric were scored and compared. The frequency of cells exhibiting multiple aberration was higher compared to that of cells exposed to Gamma radiation suggesting that effect of bleomycin might be similar to that of high LET radiation.

• Journal of Genetic Medicine
• /
• v.15 no.1
• /
• pp.8-12
• /
• 2018

Purpose: This study aimed to investigate fetal ultrasonographic findings in cases of prenatally diagnosed de novo balanced translocations and the role of fetal ultrasound in prenatal genetic counseling. Materials and Methods: We collected cases with de novo balanced translocations that were confirmed in chorionic villus sampling, amniocentesis, and cordocentesis between 1995 and 2016. A detailed, high-resolution ultrasonography was performed for prediction of prognosis. Chromosomes from the parents of affected fetuses were also analyzed to determine whether the balanced translocations were de novo or inherited. Results: Among 32,070 cases with prenatal cytogenetic analysis, 27 cases (1/1,188 incidence) with de novo balanced translocations were identified. Fourteen cases (51.9%) showed abnormal findings, and the frequency of major structural anomalies was 11.1%. Excluding the major structural anomalies, all mothers who continued pregnancies delivered healthy babies. Conclusion: Results of a detailed, high-resolution ultrasound examination are very important in genetic counseling for prenatally diagnosed de novo balanced translocations.

• Journal of Genetic Medicine
• /
• v.7 no.2
• /
• pp.156-159
• /
• 2010

Inversion, one of the balanced rearrangements, usually does not lead to phenotypic abnormalities; all genetic information exists in the proper amount, merely in a different order or in an abnormal location. However, offspring of an inversion carrier is at risk of chromosomal imbalance because an inversion loop can be formed during crossing-over of the paternal and the maternal chromosomes in meiosis. We report a 38-year-old woman with inversion and balanced translocation and her fetus with unusual rearrangement causing chromosomal imbalance. We performed conventional cytogenetic analysis, MLPA, and subtelomeric FISH in the cells of the embryo. The results showed that the distal portion of chromosome 13q was added to the terminal portion of chromosome 9p during crossing-over. Therefore, the final karyotype of the fetus was 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat, confirmed using molecular-cytogenetic analyzing tools.

• Journal of Genetic Medicine
• /
• v.19 no.1
• /
• pp.14-21
• /
• 2022

Complex chromosome rearrangements (CCRs) are structural chromosomal rearrangements involving at least three chromosomes and more than two breakpoints. CCR carriers are generally phenotypically normal but related to higher risk of recurrent miscarriage and having abnormal offspring with congenital anomalies. However, most of CCR carriers are not aware of their condition until genetic analysis of either abortus or affected baby or parental karyotyping is performed. Herein, we present the case that CCR carrier patients can be identified by preimplantation genetic testing of preimplantation embryos. An infertile male patient with severe oligoasthenoteratozoospermia was diagnosed balanced reciprocal translocation, 46,XY,t(3;11) (p26;p14) at first. After attempting the first preimplantation genetic testing for structural rearrangement (PGT-SR) cycle, we found the recurrent segmental gain or loss on 21q21.3-q22.3 of five out of nine embryos. As a result of karyotype re-analysis, the patient's karyotype showed a balanced CCR involving chromosomes 3, 11, and 21 with three breakpoints 3p26, 11p14, and 21q21. The patient underwent two PGT-SR cycles, and a pregnancy was established after the transfer of an euploid embryo in the second cycle. Amniocentesis confirmed that the baby carried normal karyotype without mosaicism. At 37 weeks gestation, a healthy girl weighting 3,050 g was born.

• Clinical and Experimental Reproductive Medicine
• /
• v.18 no.2
• /
• pp.223-231
• /
• 1991

During the years 1984 to 1989, in order to determine of chromosome abnormalities are associated with recurrent spontaneous abortions, cytogenetic studies were performed 384 couples. Abnormal karyotypes were found in 51(13.3%) couples. There was no apparent relation with the number of abortions. The abnormalities were as follows: 17(4.4%) balanced translocation; 15(3.9%) mosaicisms; 17(4.4%) pericentric inversion; 2(0.5%) addition or isochromosome. Chromosome abnormalities were observed in 34(67%) of the wives and 17(33%) of the husbands. In addition, we detected polymorphic variants of chromosomes in 89(23.2%) subjects. Reciprocal translocations(13/17) were more common than the robertsonian type(4/17). All of the mosaicisms were associated with the sex chromosomes in 10 females and 5 males subjects. Pericentric inversions were most common in chromosome 9. Compared to previously studied general populations, significantly higher frequencies of translocations, mosaicisms and inversions were found in couples with repetitive spontaneous abortion. This suggests that couples should have chromosome studies after two or more abortions.

• Journal of Genetic Medicine
• /
• v.17 no.2
• /
• pp.102-107
• /
• 2020

We report the case of an infant with a 4q35.1 deletion with 10p duplication. This mutation is rarely reported in the literature and has been found to have variable clinical findings, often including developmental delay. In this case, the condition was detected by chromosomal microarray analysis after initial manifestation of a feeding problem and developmental delay. Minor dysmorphic features with abnormal neurological examination led to further evaluation. The father's chromosome complement was 46, XY, t(4;10)(q35;p12.2). Parental balanced translocation can go unrecognized, because affected individuals are often phenotypically healthy until they have fertility issues such as recurrent miscarriages or children with severe congenital disorders. Genetic diagnoses help to establish a clear family genetic background that permits the development of clear treatment strategies. Prenatal counseling can also help to understand the possible risks associated with pregnancy or future child planning.

• Clinical and Experimental Pediatrics
• /
• v.51 no.11
• /
• pp.1241-1244
• /
• 2008

We report on 2 siblings with a partial trisomy of 7q ($7q22{\rightarrow}qter$) and concomitant partial monosomy of 8p ($8p23.3{\rightarrow}pter$), which were shown by FISH using probes located at the telomere region of each chromosome. All the balanced translocation carriers (father and a sister) in this family had a normal phenotype. The 2 siblings with the same abnormal karyotype had similar multiple congenital anomalies and dysmorphic features. During the follow-up, the first male patient died in the neonatal period, but the female sibling is still alive at 2 years and 6 months of age.