11/36. Cytogenetic studies in subgroups of rhabdomyosarcoma.rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and accounts for 10% of all solid tumors in children. There are three different histologic forms of this tumor: embryonal (RMS-E), alveolar (RMS-A), and primitive (RMS-P). Among these, the embryonal form has responded well to chemotherapy. Identification of the correct subtype is important for both the management and treatment of this malignancy. However, the histopathologic classification of RMS is sometimes difficult and distinguishing between the embryonic and primitive forms can present a diagnostic dilemma. Chromosomal abnormalities have been observed in all subtypes. We present the cytogenetic findings in six cases of RMS or related sarcoma. All four cases with RMS-A had both numerical and structural abnormalities in the tumor and involved bone marrow specimens. Three patients had a common marker, t(2;13)(q37;q14), and one patient had a variant marker involving 13q14, t(1;13) (p36;q14), and double minutes (dmin). The single embryonal RMS patient had modal chromosome numbers in the hypertriploid range and extensive structural abnormalities; the t(2;13) was not present, but translocation of 13q to both 1q and 2p was observed, der(1)t(1;13)(q21;q14) and der(2)t(2;13)(p25;q14). The patient with primitive type RMS had a hypodiploid line with several markers, including a complex translocation involving chromosomes 5 and 13 with a breakpoint at 13q14, and t(11;12)(q24;q12), a chromosome marker heretofore found only in Ewing's sarcoma and related tumors. This patient had atypical RMS with mixed neural and myogenic elements. The significance of these chromosomal markers and their importance in the characterization of childhood tumors are discussed, along with a review of the literature.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
12/36. Cystic partially differentiated nephroblastoma, embryonal rhabdomyosarcoma, and multiple congenital anomalies associated with variegated mosaic aneuploidy and premature centromere division: a case report.A rare association of embryonal genitourinary tumor(s) with cerebral malformations has been reported in eight infants with variegated mosaic aneuploidy (VMA) and premature centromere division. The authors report a new case of cystic partially differentiated nephroblastoma and embryonal rhabdomyosarcoma associated with VMA, premature centromere division, microcephalus, Dandy-Walker malformation, and cataracts. Nonrandom involvement of the chromosomes was found in VMA of the lymphocytes and the skin fibroblasts. In the cultured nephroblastoma cells, hyperdiploidy involving the same group of chromosomes involved in VMA of the somatic cells was observed, suggesting their derivation from the aneuploid population of the somatic cells.- - - - - - - - - - ranking = 1.5keywords = embryo (Clic here for more details about this article) |
13/36. Dedifferentiation in low-grade mucoepidermoid carcinoma of the parotid gland.Mucoepidermoid carcinoma (MEC), a common malignant salivary gland neoplasm, is generally divided into low-, intermediate-, and high-grade types according to the histologic features. To our knowledge, the present report describes the first case of dedifferentiation occurring in a low-grade MEC. A 55-year-old man presented with a biphasic neoplasm of the right parotid gland composed of low-grade MEC and dedifferentiated high-grade anaplastic undifferentiated carcinoma. Immunohistochemically, carcinoembryonic antigen expression was restricted to the low-grade MEC portion. The Ki-67-labeling index was higher in the dedifferentiated component than in the low-grade component. On image cytometric analysis, the low-grade MEC was diploid, whereas the dedifferentiated carcinoma was aneuploid. Although the patient was alive 10 years after the initial diagnosis, the tumor has recurred twice, at 3 months and 7 months after the initial resection. It is important to recognize that dedifferentiation can occur in a low-grade MEC, similar to other low-grade salivary gland carcinomas.- - - - - - - - - - ranking = 0.25keywords = embryo (Clic here for more details about this article) |
14/36. Double mosaic aneuploidy: 45,X/47,XY, 8 in a male infant.We report on a 13-month-old boy with abnormalities consistent with mosaic trisomy 8 syndrome and male genitalia with partial penoscrotal transposition without hypospadias, a retractile left testis in inguinal canal, and an absent right testis. A voiding cystourethrogram showed an outpouching close to the lower right side of the bladder (utriculum) and bilateral hydronephrosis secondary to vesicoureteral reflux. Peripheral blood karyotype was 45,X/47,XY, 8. The karyotype of cultured skin fibroblasts was 47,XY, 8 with no 45,X cells detected among 20 cells counted. tissues removed during surgery documented a 45,X/47,XY, 8 complement in the left testicle and utriculum, but only a 45,X line among 20 cells counted from vas deferens tissue. A possible mechanism for the origin of this previously unreported mosaicism might be an abnormal zygote with a 47,XY, 8 complement with subsequent simultaneous loss of chromosome Y and 8 in a cell at a very early embryonic stage.- - - - - - - - - - ranking = 0.25keywords = embryo (Clic here for more details about this article) |
15/36. pregnancy after cryopreservation of donor oocytes and preimplantation genetic diagnosis of embryos in a patient with ovarian failure.OBJECTIVE: To describe the successful use of preimplantation genetic diagnosis to assess the prevalence of meiotic errors after oocyte cryopreservation in an oocyte donation cycle. DESIGN: Case report. SETTING: Private IVF center. PATIENT(S): A 42.6-year-old patient with ovarian failure. INTERVENTION(S): A donor oocyte IVF cycle with cryopreservation of oocytes followed by thaw, fertilization of oocytes, preimplantation genetic diagnosis for selective aneuploidy, and ET. MAIN OUTCOME MEASURE(S): Preimplantation genetic analysis of chromosomes 13,16,18, 21,22, X, and Y with fluorescence in-situ hybridization. RESULT(S): The recipient's initial serum beta-hCG level was 196 mIU/mL 15 days after oocyte retrieval. An initial ultrasound at the sixth week of gestation revealed two gestational sacs. A second ultrasound 1 week later showed a monochorionic twin in sac A and a singleton pregnancy in sac B. Fetal cardiac activity was visualized for all gestations. CONCLUSION(S): This case illustrates the feasibility of cryopreservation of donor oocytes combined with preimplantation genetic diagnosis for clinical use in those settings where there may be an increased risk of spindle-related abnormalities.- - - - - - - - - - ranking = 125.44044962696keywords = preimplantation, embryo (Clic here for more details about this article) |
16/36. sex chromosome rearrangements leading to partial aneuploidies and mosaicisms: use of QF-PCR for detection and quantification of the involved cell lines.Chromosome rearrangements can lead to aneuploidies of specific chromosome regions and could be present in the entire individual or limited to some tissues (mosaicism) depending on the developmental stage of the embryo when the rearrangement occurs. We report 6 cases with sex chromosome rearrangements identified by conventional cytogenetics and tested by quantitative fluorescent polymerase chain reaction (QF-PCR). QF-PCR has been largely employed for rapid detection of common aneuploidies in pre-natal and post-natal diagnosis and consists in dna amplification by polymerase chain reaction (PCR) using fluorescent labelled primers and the analysis of chromosome specific small tandem repeats (STR). We tested 5 sex chromosome specific STR markers in multiplex PCR amplifications together with other chromosome specific STR markers as control amplifications. The PCR products were analysed by capillary electrophoresis. The results from QF-PCR analysis were obtained within one day and confirmed our cytogenetic observations. This study shows that QF-PCR analysis can detect sex chromosome imbalance and also suspect mosaicism or chromosome rearrangement.- - - - - - - - - - ranking = 0.25keywords = embryo (Clic here for more details about this article) |
17/36. aneuploidy 12 in a Robertsonian (13;14) carrier: Case report.In translocation carriers, the presence of aneuploidy for the chromosomes unrelated to the rearrangement may lead to an additional risk of abnormal pregnancy or implantation failure. Consequently, it may be important to analyse not only the chromosomes involved in the rearrangement but also the rest of chromosomes. We combined spectral karyotyping (SKY) and comparative genomic hybridization (CGH) to karyotype one unfertilized oocyte and its first polar body (1PB) from a Robertsonian translocation carrier t(13;14) aged 29 years who was undergoing IVF and preimplantation genetic diagnosis (PGD) for translocations and aneuploidy screening. Two out of four embryos were aneuploid, as a result of an adjacent segregation. The unfertilized oocyte had a normal/ balanced constitution of the chromosomes involved in the reorganization. However, this 1PB-metaphase II doublet was aneuploid for chromosome 12, the oocyte being hyperhaploid (24, X, 12) and its 1PB hypohaploid (22, X, -12). The application of CGH for the study of Robertsonian translocations of maternal origin will be useful to study imbalances of the chromosomes involved in the rearrangement, as well as alterations in the copy number of any other chromosome. The combination of PGD for translocations with aneuploidy screening could help to reduce the replacement of chromosomally abnormal embryos.- - - - - - - - - - ranking = 18.277207089566keywords = preimplantation, embryo (Clic here for more details about this article) |
18/36. Higher aneuploidy rates of chromosomes 13, 16, and 21 in a patient with globozoospermia.OBJECTIVE: To analyze rates of chromosomal anomalies in a patient with globozoospermia. DESIGN: Case report. SETTING: Tertiary-care infertility clinic. PATIENT(S): A 44-year-old man with 100% globozoospermia. INTERVENTION(S): Fixation of sperms and analysis of aneuploidies and diploidies by fluorescence in situ hybridization. MAIN OUTCOME MEASURE(S): aneuploidy rates of chromosomes 13, 16, and 21 and diploidy rate in a patient with 100% globozoospermia. RESULT(S): The aneuploidy rates in spermatozoa from a patient with globozoospermia were significantly higher than in a normospermic man. The incidence of a disomy of the chromosomes 13, 16, and 21 was 4%, 5%, and 1%, respectively, and the nullisomy rates were 2%, 2%, and 3%, respectively. CONCLUSION(S): This study demonstrates a positive correlation between globozoospermia and higher chromosomal aneuploidies of the chromosomes 13, 16, and 21, suggesting a higher risk of creating aneuploid embryos after intracytoplasmic sperm injection treatment for globozoospermia patients.- - - - - - - - - - ranking = 0.25keywords = embryo (Clic here for more details about this article) |
19/36. Complete cytogenetic investigation of oocytes from a young cancer patient with the use of comparative genomic hybridisation reveals meiotic errors.OBJECTIVES: The complete cytogenetic investigation of human oocytes and the corresponding first polar bodies (PBs) derived from an 18-year old female cancer patient. methods: A whole-genome amplification method combined with comparative genomic hybridisation (CGH) was employed for the analysis of 14 oocytes and their corresponding first PBs. RESULTS: Chromosome abnormalities were detected in two oocyte-PB complexes. One oocyte had lost X-chromosome material (23,X,-Xcht), while its corresponding first PB showed the reciprocal gain (23,X, Xcht). Double aneuploidy involving loss of chromatids for chromosomes X and 21 was identified in another first PB (23,X,-21cht,-Xcht). aneuploidy was attributed to unbalanced pre-division of chromatids at meiosis I. CONCLUSIONS: Meiotic errors in chromosome segregation can occur even in oocytes derived from young women, confirming the existence of age-independent factors contributing to aneuploidy. Such factors are of relevance to fertility, miscarriage and preimplantation aneuploidy screening for the purposes of increasing IVF success rates. The reliability of CGH in examining the whole chromosome complement of a single cell and of being able to detect chromatid anomalies is confirmed by this study.- - - - - - - - - - ranking = 17.777207089566keywords = preimplantation (Clic here for more details about this article) |
20/36. Preimplantation genetic diagnosis for pelizaeus-merzbacher disease with testing for age-related aneuploidies.pelizaeus-merzbacher disease (PMD) is an X-linked recessive demyelinating disorder of the central nervous system, caused by mutations of the proteolipid protein 1 gene (PLP1 gene). As no specific therapy is available for PMD, preimplantation genetic diagnosis (PGD) may be a useful option for couples carrying this mutation. PGD was performed for a couple who had had one child with the L86P mutation in exon 3 of the PLP1 gene. Because of advanced maternal age, PGD for this single-gene disorder was performed together with testing for chromosomal abnormalities. polar bodies and blastomeres were tested for the presence of maternal mutation and closely linked markers DXS8020 and PLP5' (CA)n. The same blastomeres were also tested for the copy number of chromosomes 13, 16, 18, 21, 22, X and Y, and five chromosomally abnormal embryos were identified. A total of three embryos predicted to be unaffected and free of chromosomal disorder were transferred back to the patient, resulting in a twin pregnancy and the birth of two healthy female infants confirmed to be free of PMD, representing the first PGD for PMD combined with aneuploidy testing.- - - - - - - - - - ranking = 18.277207089566keywords = preimplantation, embryo (Clic here for more details about this article) |
| <- Previous || Next -> |