Chromosomes 1 and 12 abnormalities in pediatric germ cell tumors by interphase fluorescence in situ hybridization

Chromosome studies of pediatric germ cell tumors (GCTs) show differences in abnormalities dependent on age, sex; tumor location, and histology. Previo us studies suggest that loss of Ip is associated with a malignant phenotype , while amplification of 12p, a common finding in adult testicular GCTs, is uncommon in pediatric GCTs. Fifty-three pediatric GCTs were analyzed for 1 p36 loss and 12p amplification by G-banding and dual-color interphase FISH with probes for the centromere and short arm of chromosomes 1 or 12. Twelve tumors with loss of 1p36 were identified. No deletion was detected in tumo rs with nonmalignant histology, such that there was a significant associati on of Ip loss with malignancy in these tumors (P = 0.00115). Five of 18 tum ors from male patients had amplification of 12p, consistent with G-band res ults. Combined analysis of our data with those in the literature revealed a significant correlation of 12p amplification with patient age (P = 0.00019 6). Amplification of 12p was only seen in one of 35 tumors from female pati ents. Five female GCTs had numerical abnormalities of chromosome 12, and tw o tumors showed complete lack of 12p. This spectrum of abnormalities differ s from what is seen in the male tumors, providing further evidence for diff erent etiologies of GCTs between the sexes. (C) 2001 Elsevier Science Inc. All rights reserved.