Absence of mutations in the Gs alpha and Gi2 alpha genes in sporadic parathyroid adenomas and insulinomas.

1. Activating mutations of the alpha-subunits of the Gs and Gi2 proteins give rise to the oncogenes gsp and gip2, respectively, which are found in a variety of endocrine tumours. 2. In this study the polymerase chain reaction and direct sequencing have been used to screen a small sample of parathyroid adenomas and insulinomas for these mutations. 3. No mutations were identified in nine insulinomas and 13 parathyroid adenomas screened for gsp, and 11 parathyroid adenomas and four insulinomas screened for gip2. In addition, two gastrinomas from patients with multiple endocrine neoplasia type 1 were found to be negative for both oncogenes. 4. This is the first report of screening for gip2 in parathyroid adenomas and gsp/gip2 in insulinomas, and it extends the range of tumours examined for these oncogenes.