Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Boy with bilateral retinoblastoma due to an unusual ring chromosome 13 with activation of a latent centromere

Boy with bilateral retinoblastoma due to an unusual ring chromosome 13 with activation of a... We present a patient with bilateral retinoblastoma and developmental delay who has an abnormal male karyotype containing 47 chromosomes, including an acentric derivative chromosome 13. We postulate that the derivative 13 occurred after a break at 13q14, with the proximal portion of the chromosome forming a ring and the distal portion undergoing duplication. Thus, this patient is trisomic for 13q14→qter. The derivative chromosome with duplicated distal portion (13q14→qter) lacked the 13 centromere and was negative for chromosome 13 α‐satellite DNA by low stringency FISH. Nevertheless, this chromosome is stably transmitted in lymphocytes and fibroblasts. A single primary constriction was observed at band 13q21, consistent with activation of a latent centromere (neocentromere) at this band. The neocentromere on der(13) was positive for multiple centromeric proteins, suggesting that it acts as the functional centromere. By FISH, the Rb gene was present on the normal 13, the proximally derived ring chromosome, but not on the derivative chromosome. Although there was no evidence for disruption of the Rb gene, this chromosome rearrangement most likely results in abnormal expression of the Rb gene product. © Wiley‐Liss. Inc. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png American Journal of Medical Genetics Part A Wiley

Boy with bilateral retinoblastoma due to an unusual ring chromosome 13 with activation of a latent centromere

Download PDF
8 pages

Loading next page...
 
/lp/wiley/boy-with-bilateral-retinoblastoma-due-to-an-unusual-ring-chromosome-13-FMME5T0luT

References (50)

Publisher
Wiley
Copyright
Copyright © 2001 Wiley Subscription Services, Inc., A Wiley Company
ISSN
1552-4825
eISSN
1552-4833
DOI
10.1002/1096-8628(20010215)99:1<21::AID-AJMG1122>3.0.CO;2-X
Publisher site
See Article on Publisher Site

Abstract

We present a patient with bilateral retinoblastoma and developmental delay who has an abnormal male karyotype containing 47 chromosomes, including an acentric derivative chromosome 13. We postulate that the derivative 13 occurred after a break at 13q14, with the proximal portion of the chromosome forming a ring and the distal portion undergoing duplication. Thus, this patient is trisomic for 13q14→qter. The derivative chromosome with duplicated distal portion (13q14→qter) lacked the 13 centromere and was negative for chromosome 13 α‐satellite DNA by low stringency FISH. Nevertheless, this chromosome is stably transmitted in lymphocytes and fibroblasts. A single primary constriction was observed at band 13q21, consistent with activation of a latent centromere (neocentromere) at this band. The neocentromere on der(13) was positive for multiple centromeric proteins, suggesting that it acts as the functional centromere. By FISH, the Rb gene was present on the normal 13, the proximally derived ring chromosome, but not on the derivative chromosome. Although there was no evidence for disruption of the Rb gene, this chromosome rearrangement most likely results in abnormal expression of the Rb gene product. © Wiley‐Liss. Inc.

Journal

American Journal of Medical Genetics Part A – Wiley

Published: Mar 15, 2002

Keywords: ; ; ; ;

There are no references for this article.