Loss of heterozygosity on chromosomes 1 and 11 in sporadic pheochromocytomas.

Molecular genetic analysis was performed with 20 oncogene probes and 32 polymorphic DNA probes on tumor DNA samples from seven pheochromocytomas; namely, one multiple endocrine neoplasia type 2B, and two familial and four sporadic pheochromocytomas. No amplification or rearrangement of the oncogenes was detected in any of the tumors. However, loss of heterozygosity on chromosome 1p, 11p or 11q was detected in these cases. In addition, a locus related to ETS1 was deleted in two of the sporadic tumors. These results suggest that pheochromocytomas may be genetically heterogeneous, and that inactivation of unknown genes on chromosome 1p, 11p or 11q may contribute to their development.