title: Bloom's syndrome. IV. Sister-chromatid exchanges in lymphocytes.
abstract: An abnormally great amount of exhange between both sister and nonsister-but-homologous chromatids is a highly characteristic feature of cultured blood lymphocytes from individuals with Bloom's syndrome. However, a population of lymphocytes which exhibit a normal amount of exchange can be detected in the blood of some individuals with this syndrome. This coexistence of cells with a greatly increased number of sister-chromatid exchanges and others with a normal number results in a phenotypic dimorphism, in apparent contradiction to the autosomal recessive mode of inheritance of the syndrome.
mesh_terms: D000328:Adult; D001399:Azure Stains; D002648:Child; D002869:Chromosome Aberrations; D002875:Chromosomes; D004392:Dwarfism / Q000235:genetics*; D005148:Facial Dermatoses / Q000235:genetics*; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D013684:Telangiectasis / Q000235:genetics*
chemical_list: D001399:Azure Stains