GENETIC-ASPECTS OF TUMOR-DEVELOPMENT IN MULTIPLE ENDOCRINE NEOPLASIA TYPE-1

The genetic defect predisposing to multiple endocrine neoplasia type 1 (MEN1) was mapped to chromosomal region 11q13 based on studies of all ele losses in MEN1-associated tumors and linkage to RFLP markers in fo ur Swedish MEN1 families. Combined family and tumor genotype analysis showed that tumorigenesis of both parathyroid and pancreatic tumors in volves deletions of the wild-type allele, suggesting that the MEN1 gen e is a tumor suppressor gene. Similar deletions of chromosome 11 are a lso present in sporadic parathyroid and pancreatic tumors, but are rar ely seen in sporadic pituitary tumors.