Genomic Imprinting in health and disease — ASN Events
  1. Schedule
  2. ESA Basic Symposium 3 - Beyond the gene
  3. Genomic Imprinting in health and disease

Genomic Imprinting in health and disease (#65)

Rodney Scott 1 2 3
  1. Division of Molecular Medicine, Hunter Area Pathology Service, Pathology North, New South Wales, Australia
  2. Information Based Medicine , Hunter Medical Research Institute , New South Wales, Australia
  3. The School of Biomedical Sciences, Faculty of Health, University of Newcastle, New South Wales, Australia

Genomic imprinting is an extremely subtle phenomenon that has been difficult to study yet has been known about for quite some time.   It was first described in Pseudococcus nipae1  (Mealy Bugs) in 1921.  Almost 60 years later in the early 1980’s it became clear that imprinting was also associated with certain human conditions.  Genomic imprinting describes the phenomenon of a parent of origin effect on gene expression.  In humans the most often taught example of this are two diseases that are associated with a locus on chromosome 15, Angelmans syndrome and Praeder-Willi syndrome.  Imprinting, however, extends beyond a single locus and can encompass an entire chromosome, this occurs in all female cells where one of the inherited X-chromosomes is randomly silenced via an epigenetic process involving the XIST gene.  Anomalies in this process do occur that are associated with specific differences in disease risk.  Skewing of the ratio of X-inactivation has been associated with disease, with the best example to date being breast and ovarian cancer.  Imprinting of the autosomes also can occur which has been associated with specific genomic loci and is the cause of rare but observable disease.  The quintessential example of an imprinted state is seen the diseases Praeder-Willi syndrome and Angelmans syndrome.  More recently imprinted IGF2 and H19 on chromosome 11p15.5 have been linked to parent of origin effects associated with the risk of developing Wilms tumour.   Imprinting of the 11p15.5 locus has also been associated with the hereditary overgrowth condition Beckwith-Wiedemann syndrome.   These and other diseases associated with imprinting will be discussed.

  1. Weblink http://en.wikipedia.org/wiki/Pseudococcus_nipae
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