Familial and sporadic renal onconytomas - A comparative molecular-genetic analysis

Objectives: Genetic causes of sporadic and familial renal oncocytomas are n ot known. We analyzed these tumors genetically in order to detect tumor-spe cific chromosome alterations. Methods. DNA from 26 sporadic and 31 familial renal oncocytomas were screen ed by comparative genomic hybridization according to standard protocols inc luding degenerate oligonucleotide-primed PCR. Results. Chromosome alterations were detected in 19/26 sporadic (73%) and i n 4/31 familial. renal oncocytomas, (13%). Partial or complete losses of ch romosome 1 were most frequently found in both sporadic (15/26) and familial tumors (2/4). Less frequently, loss of chromosome 14 (3/26) was, detected in sporadic renal oncocytomas as well as losses of 2p, 2q, 4q, 10 and 18 an d gains of 1q and 17q in individual sporadic tumors. Inter-tumor variation of chromosome aberrations was prominent in 1 patient, where 1 tumor showed gains of chromosomes 5, 6q, 7, 10p, 12 and 13q, whereas the second, tumor e xhibited gains of chromosomes 5 and 7 and loss of 10q. In contrast to spora dic renal oncocytomas, most familial tumors (87%) were devoid of chromosome instabilities. Conclusion: Our results demonstrate that partial or complete loss of chromo some 1 is the most common alteration in renal oncocytomas, sporadic and fam ilial. However, chromosome changes are much rarer in familial than in spora dic renal oncocytomas. Copyright (C) 2001 S. Karger AG, Basel.