Functional disomy of proximal Xp causes a distinct phenotype comprising early hypotonia, hypertelorism, small hands and feet, ear abnormalities, myopia and cognitive impairment

Authors

  • Matthew Hunter,

    1. Genetic Health Services Victoria, Royal Children's Hospital, Melbourne, Australia
    2. The Murdoch Research Institute, Royal Children's Hospital, Melbourne, Australia
    Search for more papers by this author
  • Damien Bruno,

    1. Genetic Health Services Victoria, Royal Children's Hospital, Melbourne, Australia
    2. The Murdoch Research Institute, Royal Children's Hospital, Melbourne, Australia
    Search for more papers by this author
  • David J. Amor

    Corresponding author
    1. Genetic Health Services Victoria, Royal Children's Hospital, Melbourne, Australia
    2. The Murdoch Research Institute, Royal Children's Hospital, Melbourne, Australia
    3. Department of Paediatrics, University of Melbourne, Melbourne, Australia
    • Associate Professor, Murdoch Childrens Research Institute, Flemington Rd, Parkville, Victoria 3052, Australia.

    Search for more papers by this author

  • How to cite this article: Hunter M, Bruno D, Amor DJ. 2009. Functional disomy of proximal Xp causes a distinct phenotype comprising early hypotonia, hypertelorism, small hands and feet, ear abnormalities, myopia and cognitive impairment. Am J Med Genet Part A 149A:1763–1767.

Abstract

Extra structurally abnormal chromosomes (ESACs) derived from the X chromosome are rare. We report a non-mosaic ESAC derived from the X chromosome in a 3-year-old female who presented with early hypotonia, developmental delay, hypertelorism, low set ears, and small hands and feet. The breakpoints of the ESAC were mapped by SNP microarray to Xp11.1-p11.22, a region encompassing 7.17 Mb and containing 110 known or putative genes and excluding the X-inactivation center. A review of other reported patients with karyotypes that cause functional disomy of proximal Xp allows delineation of a common phenotype comprising early hypotonia, cognitive impairment, hypertelorism, myopia, small hands and feet and abnormal external ears. © 2009 Wiley-Liss, Inc.

Ancillary