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Noonan syndrome


  • Judith E. Allanson

    Corresponding author
    • Department of Genetics, Children's Hospital of Eastern Ontario, 401 Smyth Road, Ottawa, ON K1H 8L1.
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    • Dr. Judith E. Allanson is Chief, Department of Genetics, Children's Hospital of Eastern Ontario and Professor of Pediatrics at the University of Ottawa. She received her MB ChB degree from Liverpool Medical School and trained in Internal Medicine in Britain. Her Fellowship in Medical Genetics, University of British Columbia, was under the mentorship of Dr. Judith Hall. Her research interests over the last 20 years have focused on the evaluation of facial dysmorphisms and methods of syndrome identification. She has developed objective techniques for facial evaluation and published studies of their use in many multiple congenital anomaly syndromes. Dr. Allanson is co-editor of a book on management of common genetic syndromes. She is co-chair of a Canadian Institutes of Health Research, Institute of Genetics, strategic initiative on health services research in genetics and a member of GeneSens, a health services research team based in Ottawa.

  • How to cite this article: Allanson JE. 2007. Noonan syndrome. Am J Med Genet Part C Semin Med Genet 145C:274–279.


Noonan syndrome is a common autosomal dominant condition caused by multiple genes in the RasMAPK pathway. The adult phenotype can be extremely subtle, and many adults are diagnosed only after the birth of a more obviously affected child. Whether diagnosis is made in childhood or adulthood, initial and ongoing evaluation of many systems can have considerable health benefits. © 2007 Wiley-Liss, Inc.