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Genetics of population isolates

Authors

  • M Arcos-Burgos,

    1. National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA

    2. Population Genetics, Mutacarcinogenesis and Genetic Epidemiology Group, University of Antioquia, Medellín, Colombia
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  • M Muenke

    1. National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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Corresponding author: Maximilian Muenke, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, 10 Center Drive – MSC 1852, Building 10, Room 10C103, Bethesda, MD 20892-1852, USA. Tel.: + 1-301-402-8167; fax: + 1-301-480-7876; e-mail: muenke@nih.gov

Abstract

Genetic isolates, as shown empirically by the Finnish, Old Order Amish, Hutterites, Sardinian and Jewish communities among others, represent a most important and powerful tool in genetically mapping inherited disorders. The main features associated with that genetic power are the existence of multigenerational pedigrees which are mostly descended from a small number of founders a short number of generations ago, environmental and phenotypic homogeneity, restricted geographical distribution, the presence of exhaustive and detailed records correlating individuals in very well ascertained pedigrees, and inbreeding as a norm. On the other hand, the presence of a multifounder effect or admixture among divergent populations in the founder time (e.g. the Finnish and the Paisa community from Colombia) will theoretically result in increased linkage disequilibrium among adjacent loci. The present review evaluates the historical context and features of some genetic isolates with emphasis on the basic population genetic concepts of inbreeding and genetic drift, and also the state-of-the-art in mapping traits, both Mendelian and complex, on genetic isolates.

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