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Spontaneous chromosome fragility in chorionic villus cells.

Human fragile sites are only very rarely expressed spontaneously. In this paper we report the presence of non-random spontaneous chromosome lesions (CL) in chorionic villus samples and their coincidence with fragile site (FS) bands. The average number of CL was about 9% both in RPMI-1640 and in Chang media. To determine any possible influence of external factors other than culture media, the results were grouped according to age of gestation. No differences were observed among the different groups. A total of 101 chromosome lesions could be precisely identified by sequential Leishman Staining/Wright G-banding; 76.2% of them coincided with FS-bands. The most affected region was at 1q12-1q21.1 (15.8% of total CL); other FS with a clustering of breakpoints in our study were 1p36, 1q44, 2q37, 3p24, 3q27, 10q22 and 16q23. These results suggest that spontaneous expression of some FS could be a characteristic of embryonic tissues.

Cells, Cultured↗

PubMedDate not supplied

Primary glioblastoma with EGFR amplification and a ring chromosome 7 in a young patient.

Glioblastoma is the most common primary tumor of the central nervous system, but the underlying genetic changes that give rise to these tumors are still poorly understood. We report a primary glioblastoma with an unusual age of presentation. The patient was a 22-year-old man with a survival of 16 months. Morphological findings showed an increase of cellularity with positive GFAP and EGFR expression, increase of proliferate index, vascular hyperplasia with glomeruloid structures and necrosis. Molecular analysis showed EGFR amplification. No mutations of the TP53 or amplification of MDM2 and CDK4 were detected. Neither homozygous deletion of the 9p21 locus genes nor aberrant methylation were found. The cytogenetic study showed a clonal karyotype. The metaphases presented, among other anomalies, a small ring chromosome and double-minutes chromosomes. Using FISH and CGH techniques, it was found that the ring chromosome was a partial trisomy of chromosome 7, and the region implicated corresponded to 7p13-q21. Partial trisomies in glioblastoma could play an important role in defining those regions where genes implicated in this tumor process may be found. We studied the possible correlation of these findings with the tumoral phenotype.

Adult↗