title: Mosaicism in the C-banded region of chromosome 1 in cancer families.
abstract: Chromosome 1 C-band length mosaicism was detected in lymphocytes from six tumor patients and one healthy subject belonging to three families with a high incidence of cancer. In all cases the variant cell population showed a decreased amount of C-heterochromatin in one chromosome, whereas the C-banded pattern of the homolog was identical to that of the nonvariant cell population. A family tendency to unequal mitotic crossing over, possibly leading to C-band heteromorphism, may explain the high frequency of detection of C-heterochromatin mosaicism in cancer family members (seven of 13 cases studied). The possible role of heterochromatin in inducing cancer has been widely discussed. The special feature of the acquired C-band variants vis-à-vis the inherited ones is that they mark intrinsic genetic instability that may result, through multiple mechanisms, in increased susceptibility to malignancy.
mesh_terms: D000368:Aged; D002871:Chromosome Banding; D002878:Chromosomes, Human, Pair 1; D005260:Female; D006570:Heterochromatin / Q000235:genetics / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009030:Mosaicism; D009386:Neoplastic Syndromes, Hereditary / Q000235:genetics*; D010375:Pedigree
chemical_list: D006570:Heterochromatin