The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform

Daniel L. Van Dyke - One of the best experts on this subject based on the ideXlab platform.

  • Testing for Sex Chromosome Mosaicism in Turner syndrome
    International Congress Series, 2006
    Co-Authors: Daniel L. Van Dyke, Anne E. Wiktor
    Abstract:

    Abstract Ullrich–Turner syndrome (UTS) is frequently associated with chromosomal Mosaicism. Conventional cytogenetic studies identify Sex Chromosome Mosaicism in approximately 55% of patients. Roughly 2% of UTS patients who are mosaic exhibit a cell population with 46,XY or a structural rearrangement of the Y Chromosome. Such patients are at an increased risk of gonadoblastoma and occasionally more clinically significant gonadal tumors. For UTS patients with a monosomy X karyotype result, we developed and validated a FISH assay to identify low level Mosaicism for an XY or XX cell population, or an X or Y structural rearrangement. We have tested 44 patients with monosomy X for Sex chromosomal Mosaicism using FISH. A second cell line was identified in 10 patients (23%), 6 with X/XX, 1 X/i(X), and 3 X/dic(X). None of the patients studied thus far with FISH have exhibited a Y-Chromosome cell population. FISH as an adjunct to karyotype analysis is useful to identify Sex Chromosome Mosaicism in UTS patients, and has increased the rate of identification of Mosaicism from 55% to 67%.

  • detection of low level Sex Chromosome Mosaicism in ullrich turner syndrome patients
    American Journal of Medical Genetics Part A, 2005
    Co-Authors: Anne E. Wiktor, Daniel L. Van Dyke
    Abstract:

    Ullrich-Turner syndrome (UTS) is most commonly due to a 45,X Chromosome defect, but is also seen in patients with a variety of X-Chromosome abnormalities or 45,X/46,XY Mosaicism. The phenotype of UTS patients is highly variable, and depends largely on the karyotype. Patients are at an increased risk of gonadoblastoma when a Y-derived Chromosome or Chromosome fragment is present. Since constitutional Mosaicism is present in approximately 50% of UTS patients, the identification of minor cell populations is clinically important and a challenge to laboratories. We identified 50 females with a 45,X karyotype as the sole abnormality or as part of a more complex karyotype. Twenty two (44%) had a 45,X karyotype; Mosaicism for a second normal or structurally abnormal X was observed in 24 (48%) samples, and Mosaicism for Y chromosomal material in 4 (8%) cases. To further investigate the possibility of Mosaicism in the 22 patients with an apparently non-mosaic 45,X karyotype, we performed FISH using centromere probes for the X and Y Chromosomes. A minor XX cell line was identified in 3 patients, and the 45,X result was confirmed in 19 samples. No samples with XY Mosaicism were identified. We describe our validation process for a FISH assay to be used in clinical practice to identify XX or XY Mosaicism. FISH as an adjunct to karyotype analysis provides a sensitive and cost-effective technique to identify Sex Chromosome Mosaicism in UTS patients.

  • FISH analysis helps identify low-level Mosaicism in Ullrich-Turner syndrome patients
    Genetics in Medicine, 2004
    Co-Authors: Anne Wiktor, Daniel L. Van Dyke
    Abstract:

    Purpose: To search for X or Y Chromosome Mosaicism in 45,X individuals using fluorescent in situ hybridization (FISH). Methods: From our series of 53 Ullrich-Turner syndrome patients, we used interphase FISH to evaluate the 19 who had an apparently nonmosaic 45,X karyotype with G-banding. Results: Of those 19 patients, Mosaicism was detected in seven (37%), five patients had an XX line, one had a monocentric isoChromosome X, and one had a dicentric isoChromosome X. No Y Chromosome mosaic was identified. Conclusion: FISH analysis is a sensitive and cost-effective adjunct to karyotype analysis to identify Sex Chromosome Mosaicism in UTS.

Giorgio Palestro - One of the best experts on this subject based on the ideXlab platform.

  • True hermaphroditism with XX/XY Sex Chromosome Mosaicism: Report of a case
    Clinical Genetics, 2008
    Co-Authors: M. De Marchi, Angelo O. Carbonara, Fiorenzo Carozzi, Francesca Massara, Luca Belforte, G. M. Moldsatti, Bisbocci D, M. P. Passarino, Giorgio Palestro
    Abstract:

    : A case of true hermaphroditism with 46, XX/46, XY karyotype is reported. The propositus, reared as a male, showed ambiguous external genitalia with perineoscrotal hypospadias, and internal genitalia represented by bilateral ovotestes, normal uterus and tubes. Periodic menstrual bleedings appeared at puberty. The endocrinologic data demonstrated the secretory activity of both the ovarian and the testicular tissue. The analysis of red cell, lymphocyte and serum markers, done on the propositus and on his parents, failed to show any evidence of double fertilization. On this basis, the origin of the XX/XY condition (Mosaicism versus chimerism) and its developmental consequences are discussed.

Samuel A Latt - One of the best experts on this subject based on the ideXlab platform.

  • use of y Chromosome specific probes to detect low level Sex Chromosome Mosaicism
    Clinical Genetics, 2008
    Co-Authors: Umadevi Tantravahi, Diana W Bianchi, Christine Haley, Margaret M Destrempes, Alyne T Ricker, Bruce R Korf, Samuel A Latt
    Abstract:

    An individual, found to be a true hermaphrodite at laparotomy, is presented. Cytogenetic studies which initially disclosed a 46,XX karyotype, conflicted with the anatomic presence of a testis. More extensive analysis of peripheral lymphocytes and skin fibroblasts revealed low level 46,XX/69,XXY Mosaicism. DNA hybridization studies, using highly repeated Y Chromosome specific probes, confirmed the rare presence of Y Chromosome bearing cells. Such combined clinical and molecular studies can have an important impact on diagnosis and management of cases in which Sex Chromosome Mosaicism is suspected.

M. De Marchi - One of the best experts on this subject based on the ideXlab platform.

  • True hermaphroditism with XX/XY Sex Chromosome Mosaicism: Report of a case
    Clinical Genetics, 2008
    Co-Authors: M. De Marchi, Angelo O. Carbonara, Fiorenzo Carozzi, Francesca Massara, Luca Belforte, G. M. Moldsatti, Bisbocci D, M. P. Passarino, Giorgio Palestro
    Abstract:

    : A case of true hermaphroditism with 46, XX/46, XY karyotype is reported. The propositus, reared as a male, showed ambiguous external genitalia with perineoscrotal hypospadias, and internal genitalia represented by bilateral ovotestes, normal uterus and tubes. Periodic menstrual bleedings appeared at puberty. The endocrinologic data demonstrated the secretory activity of both the ovarian and the testicular tissue. The analysis of red cell, lymphocyte and serum markers, done on the propositus and on his parents, failed to show any evidence of double fertilization. On this basis, the origin of the XX/XY condition (Mosaicism versus chimerism) and its developmental consequences are discussed.

Jiangsheng Zhu - One of the best experts on this subject based on the ideXlab platform.

  • a novel Sex Chromosome Mosaicism 45 x 45 y 46 xy 46 yy 47 xyy causing ambiguous genitalia
    Annals of Clinical and Laboratory Science, 2017
    Co-Authors: Muhammad Riaz Khan, Ihtisham Bukhari, Tang Junxiang, Liu Hui, Niaz Muhammad, Cui Fan, Jiangsheng Zhu
    Abstract:

    Sex chromosomal Mosaicism has been considered as a major cause of human Sexual differentiation disorders, like partial virilization and ambiguous genitalia. 45,X/46,XX, 45,X/46,XY and 46,XY/47,XXY are three most common Sex Chromosome mosaics associated with human ambiguous genitalia. Here, we report the case of a 3-year-old boy with ambiguous genitalia, bilateral cryptorchidism, and with an inguinal hernia. G banded cytological karyotyping and FISH analyses revealed that the patient has extremely rare and novel Sex Chromosome mosaic 45,X/45,Y/46,XY/46,YY/47,XYY karyotype. These cells exist in different percentages, important for phenotypic appearance of the patient. This is a first report of an unusual mosaic karyotype causing ambiguous genitalia.

  • A Novel Sex Chromosome Mosaicism 45,X/45,Y/46,XY/46,YY/47,XYY Causing Ambiguous Genitalia.
    Annals of clinical and laboratory science, 2017
    Co-Authors: Muhammad Riaz Khan, Ihtisham Bukhari, Tang Junxiang, Liu Hui, Niaz Muhammad, Cui Fan, Jiangsheng Zhu
    Abstract:

    Sex chromosomal Mosaicism has been considered as a major cause of human Sexual differentiation disorders, like partial virilization and ambiguous genitalia. 45,X/46,XX, 45,X/46,XY and 46,XY/47,XXY are three most common Sex Chromosome mosaics associated with human ambiguous genitalia. Here, we report the case of a 3-year-old boy with ambiguous genitalia, bilateral cryptorchidism, and with an inguinal hernia. G banded cytological karyotyping and FISH analyses revealed that the patient has extremely rare and novel Sex Chromosome mosaic 45,X/45,Y/46,XY/46,YY/47,XYY karyotype. These cells exist in different percentages, important for phenotypic appearance of the patient. This is a first report of an unusual mosaic karyotype causing ambiguous genitalia.