Background: We describe a father and son with a combination of pheochromocytoma and pancreatic islet cell tumor. Although its familial occurrence is rare, this syndrome could be called overlapping-type multiple endocrine neoplasia (MEN), since it fulfills the criteria for both type 1 and type 2 MEN. Recently, germ line mutations of the RET proto-oncogene (RET) were found to be related to tumorigenesis and disease phenotypes in type 2 MEN.
Methods: Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis, we looked for germ line mutations of RET in 8 members of this family, including the 2 patients.
Results: Analysis of RET exons 10, 11 and 16, which contain the hot-spot codons for MEN type 2, revealed no mutations in any individual examined.
Conclusion: These findings suggest that these 3 exons in RET are not related to tumorigenesis in overlapping-type MEN.