Mechanism of i(6p) formation in retinoblastoma tumor cells

Cancer Genet Cytogenet. 1989 Jan;37(1):95-102. doi: 10.1016/0165-4608(89)90079-4.


Isochromosome (6p) represents a highly characteristic cytogenetic abnormality of human retinoblastoma (RB) cells and may be important for tumor progression. To elucidate the mechanism by which this abnormal chromosome is formed, 24 RB tumors and three cell lines were studied by means of DNA polymorphisms specific for the short arm and the long arm of chromosome 6. Our results indicate that mitotic nondisjunction leading to trisomy 6 precedes the isochromosome formation. The isochromosome may then be formed by transverse division of the centromere or intrachromosomal chromatid exchange.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Chromosome Aberrations*
  • Chromosome Banding
  • Chromosomes, Human, Pair 6*
  • Eye Neoplasms / genetics*
  • Humans
  • Karyotyping
  • Models, Genetic
  • Polymorphism, Genetic
  • Retinoblastoma / genetics*
  • Tumor Cells, Cultured