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Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature

BACKGROUND: Jumping translocations are a rare type of mosaicism in which the same portion of one donor chromosome is translocated to several recipient chromosomes. Constitutional forms of jumping translocations are rare, and the 48 cases reported to date have been associated with both normal and abn...

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Autores principales: Hemmat, Morteza, Hemmat, Omid, Boyar, Fatih Z
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848363/
https://www.ncbi.nlm.nih.gov/pubmed/24020961
http://dx.doi.org/10.1186/1755-8166-6-36
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author Hemmat, Morteza
Hemmat, Omid
Boyar, Fatih Z
author_facet Hemmat, Morteza
Hemmat, Omid
Boyar, Fatih Z
author_sort Hemmat, Morteza
collection PubMed
description BACKGROUND: Jumping translocations are a rare type of mosaicism in which the same portion of one donor chromosome is translocated to several recipient chromosomes. Constitutional forms of jumping translocations are rare, and the 48 cases reported to date have been associated with both normal and abnormal phenotypes. Concurrence of isochromosome (i) of one arm and translocation of the other is also rare, with seven reported cases. We describe a unique case involving concurrence of i(Yp) and a jumping translocation of Yq to the telomere of chromosomes 12q and 17q, which resulted in five cell lines. CASE PRESENTATION: The patient, an otherwise healthy 35-year-old man, was referred for cytogenetic studies because of absolute azoospermia. He had elevated levels of follicle stimulating hormone and luteinizing hormone, consistent with abnormal spermatogenesis, and decreased levels of free testosterone and inhibin B. G-banded chromosome analysis revealed a mosaic male karyotype involving five abnormal cell lines. One of the cell lines showed loss of chromosome Y and presence of i(Yp) as the sole abnormality. Three cell lines exhibited jumping translocation: two involved 17qter, and the other involved 12qter as the recipient and Yq as the common donor chromosome. One of the cell lines with der(17) additionally showed i(Yp). The other der(17) and der(12) cell lines had a missing Y chromosome. All five cell lines were confirmed by FISH. Subtelomric FISH study demonstrated no loss of chromosome material from the recipient chromosomes at the translocation junctions. CONCLUSIONS: We postulate that a postzygotic pericentromeric break of the Y chromosome led to formation of isochromosome Yp, whereas Yq formed a jumping translocation through recombination between its internal telomere repeats and telomeric repeats of recipient chromosomes. This in turn led to either pairing or an exchange at the complimentary sequences. Such translocation junctions appear to be unstable and to result in a jumping translocation. Cryptic deletion or disruption of AZF (azoospermic factor) genes at Yq11 during translocation or defective pairing of X and Y chromosomes during meiosis, with abnormal sex vesicle formation and consequent spermatogenetic arrest, might be the main cause of the azoospermia in our patient.
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spelling pubmed-38483632013-12-04 Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature Hemmat, Morteza Hemmat, Omid Boyar, Fatih Z Mol Cytogenet Case Report BACKGROUND: Jumping translocations are a rare type of mosaicism in which the same portion of one donor chromosome is translocated to several recipient chromosomes. Constitutional forms of jumping translocations are rare, and the 48 cases reported to date have been associated with both normal and abnormal phenotypes. Concurrence of isochromosome (i) of one arm and translocation of the other is also rare, with seven reported cases. We describe a unique case involving concurrence of i(Yp) and a jumping translocation of Yq to the telomere of chromosomes 12q and 17q, which resulted in five cell lines. CASE PRESENTATION: The patient, an otherwise healthy 35-year-old man, was referred for cytogenetic studies because of absolute azoospermia. He had elevated levels of follicle stimulating hormone and luteinizing hormone, consistent with abnormal spermatogenesis, and decreased levels of free testosterone and inhibin B. G-banded chromosome analysis revealed a mosaic male karyotype involving five abnormal cell lines. One of the cell lines showed loss of chromosome Y and presence of i(Yp) as the sole abnormality. Three cell lines exhibited jumping translocation: two involved 17qter, and the other involved 12qter as the recipient and Yq as the common donor chromosome. One of the cell lines with der(17) additionally showed i(Yp). The other der(17) and der(12) cell lines had a missing Y chromosome. All five cell lines were confirmed by FISH. Subtelomric FISH study demonstrated no loss of chromosome material from the recipient chromosomes at the translocation junctions. CONCLUSIONS: We postulate that a postzygotic pericentromeric break of the Y chromosome led to formation of isochromosome Yp, whereas Yq formed a jumping translocation through recombination between its internal telomere repeats and telomeric repeats of recipient chromosomes. This in turn led to either pairing or an exchange at the complimentary sequences. Such translocation junctions appear to be unstable and to result in a jumping translocation. Cryptic deletion or disruption of AZF (azoospermic factor) genes at Yq11 during translocation or defective pairing of X and Y chromosomes during meiosis, with abnormal sex vesicle formation and consequent spermatogenetic arrest, might be the main cause of the azoospermia in our patient. BioMed Central 2013-09-10 /pmc/articles/PMC3848363/ /pubmed/24020961 http://dx.doi.org/10.1186/1755-8166-6-36 Text en Copyright © 2013 Hemmat et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Case Report
Hemmat, Morteza
Hemmat, Omid
Boyar, Fatih Z
Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title_full Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title_fullStr Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title_full_unstemmed Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title_short Isochromosome Yp and jumping translocation of Yq resulting in five cell lines in an infertile male: a case report and review of the literature
title_sort isochromosome yp and jumping translocation of yq resulting in five cell lines in an infertile male: a case report and review of the literature
topic Case Report
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848363/
https://www.ncbi.nlm.nih.gov/pubmed/24020961
http://dx.doi.org/10.1186/1755-8166-6-36
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