An in-frame trinucleotide repeat in the coding region of the human cellular glutathione peroxidase (GPX1) gene: in vivo polymorphism and in vitro instability

Genomics. 1994 Sep 1;23(1):292-4. doi: 10.1006/geno.1994.1499.


We report the variation in vivo and instability in vitro of an in-frame GCG trinucleotide repeat in the human cellular glutathione peroxidase (GPX1) gene. In a population study of 110 alleles from 55 unrelated individuals, the allele frequencies for 4, 5, and 6 GCG repeats were 0.40, 0.35, and 0.25, respectively. No allele was associated with diminished enzyme activity. Current stocks of HL-60 cells, a human myeloid leukemia cell line, are homozygous for the 6-repeat allele. Early passage HL-60 cells frozen in 1976 show a 4/6 genotype and "intermediate" passage cells frozen in 1985 contain both 4/6 and 5/6 genotypes. Thus, the expansion of the repeat appears to have developed in the course of multiple passages of the rapidly proliferating cell line.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Base Sequence
  • Chromosomes, Human, Pair 3
  • DNA, Neoplasm / genetics
  • Gene Frequency
  • Genes
  • Genotype
  • Glutathione Peroxidase / genetics*
  • Humans
  • Leukemia, Promyelocytic, Acute / pathology
  • Minisatellite Repeats*
  • Molecular Sequence Data
  • Polymorphism, Genetic*
  • Tumor Cells, Cultured


  • DNA, Neoplasm
  • Glutathione Peroxidase