title: Overrepresentation of chromosome 12p sequences and karyotypic evolution in i(12p)-negative testicular germ-cell tumors revealed by fluorescence in situ hybridization.
abstract: Human testicular germ-cell tumors (TGCTs) comprise a heterogeneous group of solid neoplasms. These tumors are characterized by the presence of a highly specific chromosomal abnormality, i.e., an isochromosome of the short arm of chromosome 12. At present, this i(12p) chromosome is found in more than 80% of TGCTs. Isochromosome 12p has also been observed in some ovarian and extragonadal germ cell tumors. In the remaining so-called i(12p)-negative TGCTs other abnormalities involving chromosome 12, mainly 12p, can be found. In order to establish whether 12p abnormalities other than i(12p) are a common phenomenon in TGCTs, a panel of 11 i(12p)-negative tumors was investigated using multicolor fluorescence in situ hybridization. All TGCTs examined appeared to contain chromosomal abnormalities involving 12p, resulting in a distinct overrepresentation of short arm sequences. In addition, indications were obtained for a clonal evolution in one of the tumors. Our data suggest that the occurrence of 12p abnormalities is a common phenomenon in i(12p)-negative TGCTs and that these abnormalities, analogous to i(12p), may contribute to the process of tumor development.
authors.affiliation: Department of Human Genetics, University Hospital, Nijmegen, The Netherlands.
authors.forename: R F
authors.initials: RF
authors.lastname: Suijkerbuijk
authors.forename: R J
authors.initials: RJ
authors.lastname: Sinke
authors.forename: A M
authors.initials: AM
authors.lastname: Meloni
authors.forename: J M
authors.initials: JM
authors.lastname: Parrington
authors.forename: J
authors.initials: J
authors.lastname: van Echten
authors.forename: B
authors.initials: B
authors.lastname: de Jong
authors.forename: J W
authors.initials: JW
authors.lastname: Oosterhuis
authors.forename: A A
authors.initials: AA
authors.lastname: Sandberg
authors.forename: A
authors.initials: A
authors.lastname: Geurts van Kessel
mesh_terms: D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002881:Chromosomes, Human, Pair 12 / Q000648:ultrastructure*; D018237:Germinoma / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D013736:Testicular Neoplasms / Q000235:genetics*; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured