Chromosome 1 in 26 carcinomas of the cervix uteri: structural and numerical changes.

Cytogenetic studies on 26 carcinomas of the cervix showed that chromosome 1 was consistently involved in the changes: either one or more structurally abnormal chromosomes or a relative excess of normal chromosomes were present. Several types of structural change were repeatedly seen: short arm deletions (1p-, in seven tumors); long arm isochromosomes (i(1q), in six tumors); and translocations of unidentified chromosomal material onto one of the arms (possibly in eleven tumors; in four of these, there was an additional C-band on the long arm). In one tumor, there was a short arm isochromosome (i(1p)). The most consistent feature of the aneuploid complements of these tumors appeared to be the presence in excess of the centromeric region and at least part of the adjacent heterochromatin of chromosome 1.