Human Genetics

, Volume 95, Issue 2, pp 161–170

Supernumerary marker 15 chromosomes: a clinical, molecular and FISH approach to diagnosis and prognosis

  • John A. Crolla
  • John F. Harvey
  • Fiona L. Sitch
  • Nick R. Dennis
Original Investigation

DOI: 10.1007/BF00209395

Cite this article as:
Crolla, J.A., Harvey, J.F., Sitch, F.L. et al. Hum Genet (1995) 95: 161. doi:10.1007/BF00209395

Abstract

Seventeen patients presenting with either de novo or familial supernumerary marker (mar) 15 chromosomes were shown by fluorescent in situ hybridization techniques (FISH) to have markers derived from and composed entirely of chromosome 15 material. Using a combination of conventional cytogenetics, FISH, Southern blotting and multiplex polymerase chain reaction (PCR) methods, it was possible to sub-classify the 17 mar(15)s into six distinct morphological and molecular groups. Analysis of DNA and metaphase spreads from the probands and their parents using probes and primers from the pericentromeric and Prader-Willi/Angelman syndromes critical regions (PWS/AS), clearly differentiated between marker 15 s which included the PWS/AS critical regions and those which did not. A direct correlation between the presence of the PWS/AS region in the mar(15) and severe mental retardation was observed. Based on these results, a system of classification of supernumerary marker 15 chromosomes is proposed.

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • John A. Crolla
    • 1
  • John F. Harvey
    • 1
  • Fiona L. Sitch
    • 1
  • Nick R. Dennis
    • 2
  1. 1.Wessex Regional Genetics Laboratory, Salisbury District HospitalSalisburyUK
  2. 2.Wessex Clinical Genetics Service, The Princess Anne HospitalSouthamptonUK