Exclusion of the phosphatidylinositol-specific phospholipase C β3 (PLC β3) gene as candidate for the multiple endocrine neoplasia type 1 (MEN 1) gene

摘要

Multiple endocrine neoplasia type 1 (MEN 1) is inherited as an autosomal dominant disorder, characterized by hyperplasia and neoplasia in several endocrine organs. The MEN 1 gene, which is most probably a tumor suppressor gene, has been localized to a 900-kb region on chromosome 11q13. The human phosphatidylinositol-specific phospholipase C β3 (PLC β3) gene, which is located within this region, was considered to be a good candidate for the MEN 1 gene. In this study, the structure and expression of the PLC β3 gene in MEN 1 patients were investigated in more detail, to determine its potential role in MEN 1 tumorigenesis. Southern blot analysis, using blood and tumor DNA from affected persons from seven different MEN 1 families, did not reveal structural abnormalities in the PLC β3 gene. To detect possible point mutations, or other small structural aberrations, direct sequencing of PLC β3 cDNAs from two affected persons from two different MEN 1 families was performed, but no MEN 1-specific abnormalities were revealed. Several common nucleotide sequence polymorphisms were detected in these cDNAs, proving that both alleles of the PLC β3 gene were expressed and analyzed. In conclusion, these results exclude the PLC β3 gene as a candidate gene for