The Experts below are selected from a list of 4770 Experts worldwide ranked by ideXlab platform
Lisa G Shaffer - One of the best experts on this subject based on the ideXlab platform.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome. © 2002 Wiley-Liss, Inc.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome.
-
Prenatal diagnosis of a homologous Robertsonian Translocation involving chromosome 15
Prenatal Diagnosis, 2001Co-Authors: Debra J. Abrams, Lisa G Shaffer, Sue Ann Berend, Amy R. Aronoff, Benjamin B. Roa, Mark R. GeierAbstract:We report the prenatal diagnosis of a fetus with a de novo Robertsonian Translocation: 45,XY,der(15;15)(q10;q10). Although Robertsonian Translocations are common chromosomal rearrangements, those involving homologous chromosomes are infrequent. Since chromosome 15 is imprinted, uniparental disomy (UPD) is a concern when chromosomal rearrangements involving chromosome 15 are identified. In the present case, UPD studies showed normal biparental inheritance. In contrast to the fact that most homologous acrocentric rearrangements are isochromosomes, these results indicate postzygotic formation of a Robertsonian Translocation between biparentally inherited chromosomes 15. Copyright © 2001 John Wiley & Sons, Ltd.
-
prenatal diagnosis of a fetus with a homologous Robertsonian Translocation of chromosomes 15
American Journal of Medical Genetics, 1997Co-Authors: Sau Wai Cheung, Lisa G Shaffer, Sue C Richards, Scott L Page, Daniel L RicondaAbstract:We present a prenatal diagnosis of a de novo homologous Robertsonian Translocation involving both chromosomes 15. Amniocentesis was performed on a 36-year-old woman at 16.5 weeks of gestation. Chromosome analysis documented a 45,XX,der(15;15)(q10;q10) chromosome pattern. No evidence of a deletion was observed by FISH using a SNRPN DNA probe associated with the Prader-Willi/Angelman syndrome critical region. Molecular studies in the family using six polymorphic markers for chromosome 15 and Southern blot analysis of DNA methylation for the CpG island near the SNRPN gene showed normal biparental inheritance of chromosome 15, excluding uniparental disomy. The patient was counseled that her child would not be able to bear offspring without clinical assistance. Otherwise the health and intellect of her child were not expected to be affected by the Translocation. We consider this to be the first prenatal case identified with a balanced der(15;15)(q10;q10) Robertsonian Translocation and a phenotypically normal female outcome. Prenatally identified cases of der(15;15)(q10;q10) warrant further investigation by molecular methodology. Am. J. Med. Genet. 72:47–50, 1997. © 1997 Wiley-Liss, Inc.
-
Breakpoint Diversity Illustrates Distinct Mechanisms for Robertsonian Translocation Formation
Human Molecular Genetics, 1996Co-Authors: Scott L Page, Jong-chul Shin, Jin-yeong Han, K. H. Andy Choo, Lisa G ShafferAbstract:Robertsonian Translocations are the most common chromosomal rearrangements in humans. The vast majority of the ten possible nonhomologous types of Robertsonian Translocations ascertained are rob(13q14q) and rob(14q21q). Recombination between homologous sequences on nonhomologous chromosomes has been proposed as a mechanism leading to the preferential formation of rob(13q14q) and rob(14q21q). However, little evidence exists to indicate whether the remaining less common Robertsonian Translocations form through a similar mechanism. To better elucidate the mechanisms involved in Robertsonian Translocation formation, we have used fluorescence in situ hybridization to localize the breakpoints in 56 nonhomologous Robertsonian Translocations. This study revealed highly variable locations of breakpoints in seven types of the less common Robertsonians, while nearly all rob(13q14q) and rob(14q21q) analyzed displayed breakpoints in the same locations. Therefore, this study provides direct evidence that rob(13q14q) and rob(14q21q) form through a specific mechanism, possibly involving homologous recombination, which is distinct from the mechanism(s) that contributes to the formation of the remaining types of Robertsonian Translocations.
Sue Ann Berend - One of the best experts on this subject based on the ideXlab platform.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome. © 2002 Wiley-Liss, Inc.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome.
-
Prenatal diagnosis of a homologous Robertsonian Translocation involving chromosome 15
Prenatal Diagnosis, 2001Co-Authors: Debra J. Abrams, Lisa G Shaffer, Sue Ann Berend, Amy R. Aronoff, Benjamin B. Roa, Mark R. GeierAbstract:We report the prenatal diagnosis of a fetus with a de novo Robertsonian Translocation: 45,XY,der(15;15)(q10;q10). Although Robertsonian Translocations are common chromosomal rearrangements, those involving homologous chromosomes are infrequent. Since chromosome 15 is imprinted, uniparental disomy (UPD) is a concern when chromosomal rearrangements involving chromosome 15 are identified. In the present case, UPD studies showed normal biparental inheritance. In contrast to the fact that most homologous acrocentric rearrangements are isochromosomes, these results indicate postzygotic formation of a Robertsonian Translocation between biparentally inherited chromosomes 15. Copyright © 2001 John Wiley & Sons, Ltd.
Ruma Bandyopadhyay - One of the best experts on this subject based on the ideXlab platform.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome. © 2002 Wiley-Liss, Inc.
-
mosaicism in a patient with down syndrome reveals post fertilization formation of a Robertsonian Translocation and isochromosome
American Journal of Medical Genetics Part A, 2003Co-Authors: Ruma Bandyopadhyay, Lisa G Shaffer, Sue Ann Berend, Christopher Mccaskill, Cami Knoxdu Bois, Yaolin Zhou, Emilia K BijlsmaAbstract:It has been estimated that a few hundred children are born each year in the United States with Translocation Down syndrome. About 5% of the cases with Down syndrome carry a Robertsonian Translocation involving chromosome 21. The case described here is a patient with Down syndrome who showed mosaicism for two cell lines. Each cell line contains a different, de novo acrocentric rearrangement. We constructed somatic cell hybrids from the patient's cells and determined the parental origins of the rearrangements by molecular and fluorescence in situ hybridization (FISH) analyses. The analysis showed that the rob(14q21q) formed between a paternally inherited chromosome 21 and a maternally inherited chromosome 14, indicating that this rearrangement formed post-zygotically. Further molecular analysis also determined that the rea(21q21q) is an isochromosome of paternal origin. The cell line containing the isochromosome is unbalanced, resulting in trisomy 21. Because the same paternal chromosome 21 was involved in both the isochromosome and the Robertsonian Translocation, we speculate that an unstable chromosome 21 was stabilized either through formation of a rob(14q21q) or through formation of an isochromosome. The mechanism proposed for the formation of the rob(14q21q) in this case is different from that for most de novo rob(14q21q), but similar to a previously reported mosaic case of Down syndrome.
Bertrand Mace - One of the best experts on this subject based on the ideXlab platform.
-
molecular cytogenetics analysis with whole chromosome paint probes of sperm nuclei from a 13 15 Robertsonian Translocation carrier
Journal of Human Genetics, 2005Co-Authors: Nathalie Rives, Celia Ravel, Veronique Duchesne, Jeanpierre Siffroi, Nathalie Moussetsimeon, Bertrand MaceAbstract:Meiotic segregation of a Robertsonian Translocation (13;15) was assessed in sperm nuclei using dual-color fluorescent in situ hybridization (FISH) with whole-chromosome paint probes. Most spermatozoa in the (13;15) Translocation carrier resulted from alternate segregation. Although an increased frequency of unbalanced gametes was observed, spontaneous pregnancy led to the birth of a boy with a normal karyotype.
Daniel L Riconda - One of the best experts on this subject based on the ideXlab platform.
-
prenatal diagnosis of a fetus with a homologous Robertsonian Translocation of chromosomes 15
American Journal of Medical Genetics, 1997Co-Authors: Sau Wai Cheung, Lisa G Shaffer, Sue C Richards, Scott L Page, Daniel L RicondaAbstract:We present a prenatal diagnosis of a de novo homologous Robertsonian Translocation involving both chromosomes 15. Amniocentesis was performed on a 36-year-old woman at 16.5 weeks of gestation. Chromosome analysis documented a 45,XX,der(15;15)(q10;q10) chromosome pattern. No evidence of a deletion was observed by FISH using a SNRPN DNA probe associated with the Prader-Willi/Angelman syndrome critical region. Molecular studies in the family using six polymorphic markers for chromosome 15 and Southern blot analysis of DNA methylation for the CpG island near the SNRPN gene showed normal biparental inheritance of chromosome 15, excluding uniparental disomy. The patient was counseled that her child would not be able to bear offspring without clinical assistance. Otherwise the health and intellect of her child were not expected to be affected by the Translocation. We consider this to be the first prenatal case identified with a balanced der(15;15)(q10;q10) Robertsonian Translocation and a phenotypically normal female outcome. Prenatally identified cases of der(15;15)(q10;q10) warrant further investigation by molecular methodology. Am. J. Med. Genet. 72:47–50, 1997. © 1997 Wiley-Liss, Inc.
