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

Matthew Hunter, Damien Bruno, David J. Amor

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3 Citations (Scopus)


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 7.17Mb 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.

Original languageEnglish
Pages (from-to)1763-1767
Number of pages5
JournalAmerican Journal of Medical Genetics, Part A
Issue number8
Publication statusPublished - Aug 2009
Externally publishedYes


  • ESAC
  • Functional disomy
  • Marker chromosome
  • X chromosome

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