Monosomy 1p36 deletion syndrome


  • Marzena Gajecka,

    1. Department of Health Research and Education at Washington State University in Spokane. Her research focuses on the mechanisms involved in chromosomal rearrangements
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  • Katherine L. Mackay,

    1. Health Policy and Administration at Washington State University in Spokane
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  • Lisa G. Shaffer

    Corresponding author
    1. Signature Genomic Laboratories, LLC, in Spokane, WA. She is also a professor at Washington State University. Dr. Shaffer received her PhD from the Medical College of Virginia
    • Health Research and Education Center, Washington State University, Box 1495, Spokane, WA 99210-1495.
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  • How to cite this article: Gajecka M, Mackay KL, Shaffer LG. 2007. Monosomy 1p36 deletion syndrome. Am J Med Genet Part C Semin Med Genet 145C:346–356.


Monosomy 1p36 results from a heterozygous deletion of the most distal chromosomal band on the short arm of chromosome 1. Occurring in ∼1 in 5,000 live births, monosomy 1p36 is the most common terminal deletion observed in humans. Monosomy 1p36 is associated with mental retardation, developmental delay, hearing impairment, seizures, growth impairment, hypotonia, and heart defects. The syndrome is also characterized by several distinct dysmorphic features, including large anterior fontanels, microcephaly, brachycephaly, deep-set eyes, flat nose and nasal bridge, and pointed chin. Several genes have been proposed as causative for individual features of the phenotype. In addition, based upon molecular characterization of subjects with monosomy 1p36, several mechanisms for the generation and stabilization of terminal deletions have been proposed. © 2007 Wiley-Liss, Inc.