Pericentromeric structure of human X "isochromosomes": evidence for molecular heterogeneity.


Journal Article

Three different long-arm X isochromosomes and an isodicentric X chromosome were examined by in situ hybridization with X-chromosome-specific alpha-satellite probes and by quantitation of Southern blots hybridized with proximal short-arm probes. Each chromosome had a unique pericentromeric structure. The isodicentric X chromosome was clearly dicentric, showing two distinct alpha-satellite hybridization signals and duplication of short-arm material. Two isochromosomes showed a larger than normal, bifid alpha-satellite signal and also had duplications of different extents of short-arm material. The third X isochromosome could not be distinguished from a classical long-arm isochromosome; it did not have a short-arm duplication and it had a single alpha-satellite signal. These data indicate that rearrangements responsible for X isochromosome formation can occur at numerous locations in the pericentromeric region and that some X isochromosomes may involve duplications of substantial portions of the short arm.

Full Text

Cited Authors

  • Sharp, CB; Bedford, HM; Willard, HF

Published Date

  • August 1990

Published In

Volume / Issue

  • 85 / 3

Start / End Page

  • 330 - 336

PubMed ID

  • 2394446

Pubmed Central ID

  • 2394446

Electronic International Standard Serial Number (EISSN)

  • 1432-1203

International Standard Serial Number (ISSN)

  • 0340-6717

Digital Object Identifier (DOI)

  • 10.1007/bf00206757


  • eng