1/431. A trisomic germ cell line and precocious chromatid segregation leads to recurrent trisomy 21 conception.A chromosomally normal 37-year-old woman was referred for preimplantation genetic diagnosis after having several conceptuses with trisomy 21. Segregation of chromosome 21 was assessed in unfertilised meiosis II oocytes and preimplantation embryos from PGD cycles using fluorescent in situ hybridisation (FISH). Of 7 preimplantation embryos, 5 were chromosomally abnormal with 4 having trisomy 21 and one being tetraploid. Of 4 oocytes, 3 had an abnormal chromosomal constitution with either an extra chromosome 21 or an extra chromatid 21. In one oocyte an extra chromatid 21 was detected in both the metaphase II complement and the first polar body providing the first direct evidence of a maternal trisomic germ cell line. Moreover, this result shows that the extra chromosome 21 can precociously divide into its two chromatids at the first meiotic division.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/431. trisomy 21 associated transient neonatal myeloproliferation in the absence of Down's syndrome.Although usually associated with Down's syndrome, transient neonatal myeloproliferation (TMD) can occur in the absence of a constitutional trisomy 21. This report describes two such cases, both of whom had a trisomy 21 restricted to clonal cells. Unlike in previous such reported cases, spontaneous morphological, cytogenetic, and molecular remission in both cases was followed by re-emergence, in one case, of an evolved clone with a more malignant phenotype which required pharmacological intervention. awareness that trisomy 21 bearing leukaemia in the neonatal period can be transient even in the absence of Down's syndrome is important to prevent unnecessary treatment. Equally, such cases require indefinite follow up as a proportion may have a recurrence which may require treatment.- - - - - - - - - - ranking = 0.0010256295601652keywords = ring (Clic here for more details about this article) |
3/431. Intracranial germ cell tumors in children with and without down syndrome.PURPOSE: Two Chinese children with down syndrome affected by intracranial germ cell tumors are described. Because they represent two of eight affected patients in the current series from 1990 to 1996, it is postulated that such occurrence may be more than a coincidental event. patients AND methods: Two children with down syndrome developed germ cell tumors in atypical intracranial sites that affected basal ganglion and cerebellum. The pathology showed germinoma and yolk sac tumor, respectively. These were treated by radical surgical resection and chemotherapy with cisplatin, etoposide, and bleomycin, but without radiotherapy. RESULTS: One patient survived 3 years without radiologic evidence of tumor. The other died from infective complications caused by severe myelosuppression after chemotherapy. CONCLUSIONS: Subtle neurologic manifestations in developmentally handicapped patients with intracranial space-occupying lesions could result in delayed diagnosis. Children with down syndrome suffering from brain tumors may have a higher chance for germ cell tumors. Assay for alpha-fetoprotein and beta-human chorionic gonadotrophin could hasten diagnosis in some cases. This observation and review of literature suggest an increased risk of developing intracranial germ cell tumors in subjects with down syndrome.- - - - - - - - - - ranking = 0.0010256295601652keywords = ring (Clic here for more details about this article) |
4/431. trisomy/tetrasomy 21 mosaicism in CVS: interpretation of cytogenetic discrepancies between placental and fetal chromosome complements.trisomy/tetrasomy 21 mosaicism was found in chorionic villi (semidirect preparation) obtained from a 40 year old pregnant woman. Since both cell lines were abnormal, the couple elected for pregnancy termination. placenta and fetal tissue samples were obtained for cytogenetic study. Long term cultured villi showed a non-mosaic trisomy 21 karyotype, while other tissues showed either a normal karyotype or normal/trisomy21 mosaicism. These discrepancies could be explained by a modified "bottle neck" embryogenic model with a trisomic zygote and a non-disjunction event taking place in one of the first divisions. Our case emphasises the need for confirmatory studies in other tissues when mosaicism is encountered in chorionic villi, even if all cell lines are abnormal.- - - - - - - - - - ranking = 1.3333333333333keywords = chromosome (Clic here for more details about this article) |
5/431. seminoma associated with bilateral cryptorchidism in Down's syndrome: a case report.BACKGROUND: A case of testicular typical seminoma associated with bilateral undescended testes in Down's syndrome is reported. A 42-year-old institutionalized male patient developed left testicular seminoma with retroperitoneal metastasis. methods/RESULTS: Neither adjuvant chemotherapy nor radiotherapy were performed due to his severe mental retardation. He died as a result of the cancer 2 years after a left radical orchiectomy and an autopsy was carried out. DISCUSSION: Recently an increase in the incidence of the association of testicular tumors and Down's syndrome has been repeatedly documented. Thirty-six cases of testicular tumors associated with Down's syndrome have been reported and of these 17.1% had cryptorchidism. This is a much lower percentage considering the high risk of cryptorchidism in males with Down's syndrome. The relationship between testicular germ cell tumors associated with cryptorchidism and Down's syndrome is discussed.- - - - - - - - - - ranking = 0.0010256295601652keywords = ring (Clic here for more details about this article) |
6/431. Variable levels of mosaicism for trisomy 21 in a non-immune hydropic infant with chylothorax.We report the first case of mosaic trisomy 21 with non-immune hydrops fetalis and bilateral chylothoraces. Prenatal fetal blood karyotype analysis of 15 fetal cells revealed a 46,XX karyotype. Aggressive prenatal management, including fetal thoracocentesis and pleuro-amniotic shunt, was performed. A clinical phenotype of down syndrome was apparent after the gross oedema had subsided. Subsequent chromosome study of neonatal blood lymphocytes showed mosaic trisomy 21 with 23 per cent trisomic cells. review of the initial fetal blood sample identified trisomy in 5 per cent of 134 cells. Follow-up study at five months showed no trisomy 21 in 100 cells. This case illustrates the variable levels of mosaicism manifest in the peripheral blood of an infant with obvious down syndrome phenotype, and the limitation of cytogenetic analysis of peripheral lymphocytes alone in prenatal and postnatal detection of low levels of mosaicism.- - - - - - - - - - ranking = 0.33333333333333keywords = chromosome (Clic here for more details about this article) |
7/431. Prenatal ultrasound detection of congenital cataract in trisomy 21.A 45-year-old woman underwent serial ultrasound screening procedures during late first and second trimesters of pregnancy for advanced maternal age. Cultured amniocytes karyotype indicated full trisomy 21. Subsequently, the fetus developed congenital cataract diagnosed at 24 weeks. This is the first antenatal diagnosis of this complication of down syndrome.- - - - - - - - - - ranking = 0.0010256295601652keywords = ring (Clic here for more details about this article) |
8/431. Cervical spondylarthrotic myelopathy with early onset in Down's syndrome: five cases and a review of the literature.Progressive walking difficulties and bladder dysfunction may be attributed to alzheimer disease or atlanto-axial subluxation in people with Down's syndrome (DS). The present authors describe five patients with DS suffering from the above symptoms as a result of cervical spondylarthrotic myelopathy. Clinical and radiological data were collected from all patients with DS who underwent surgery for cervical spondylarthrotic myelopathy at the Leiden University Medical Centre during the period between 1991 and 1995. Five patients with DS (four males and one female) were identified. Their mean age at diagnosis was 42 years. The main clinical features were weakness of the arms and legs, ataxic gait, hyperreflexia and bilateral Babinski signs. Radiological examination showed spondylarthrosis, compression of the spinal cord and myelomalacia. The mean delay in diagnosis was 3 years. All five individuals showed clinical stabilization after laminectomy. Cervical spondylarthrotic myelopathy seems a rather frequent disorder in DS, occurring at a relatively young age. early diagnosis may prevent irreversible neurological deficits.- - - - - - - - - - ranking = 0.0030768886804956keywords = ring (Clic here for more details about this article) |
9/431. Transient leukemoid disorder in a newborn with down syndrome followed 19 months later by an acute myeloid leukemia: demonstration of the same structural change in both instances with clonal evolution.A transient leukemoid disorder (TLD) was observed in a newborn with down syndrome (DS), demonstrating a clonal abnormality: 47,XX,der(X;15)(p10;q10), 21(c). Spontaneous remission was observed, but 19 months later an acute leukemia from the myeloid series was discovered. Cytogenetic study revealed the same structural change as at birth, with karyotypic evolution corresponding to addition of one chromosome 8 and a fourth chromosome 21. These findings demonstrate, at least in our patient, that TLD and the subsequent acute leukemia are closely related and that TLD, closely related to DS, must be viewed as a preleukemic disorder undergoing spontaneous remission. A review of literature data shows that most cytogenetic studies reported so far are related to either TLD or acute leukemia in DS. Serial studies performed in the same patient are quite infrequent and, to the best of our knowledge, there is only one other report demonstrating a cytogenetic relation between TLD and the subsequent acute leukemia.- - - - - - - - - - ranking = 0.66666666666667keywords = chromosome (Clic here for more details about this article) |
10/431. trisomy 21 as the sole abnormality in a refractory anemia with ring sideroblasts.Numerous chromosome abnormalities have been described in myelodysplastic syndromes, but single karyotypic aberrations are much less frequent. We report the case of a 65-year-old woman who presented a trisomy 21 as the sole karyotypic anomaly for a refractory anemia with ring sideroblasts. The nature of such an anomaly is discussed in regard to pathogenesis and prognosis.- - - - - - - - - - ranking = 0.33846148113416keywords = chromosome, ring (Clic here for more details about this article) |
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