Bi-directional sequencing of exons 8 and 9 of the GNAS gene to detect mutation hot spots in codons R201 and Q227.
Guanine nucleotide-binding protein/alpha-subunit (GNAS) gene is mutated, over-expressed and/or amplified in a number of diseases. GNAS mutations have been reported in 28% of pituitary gland tumors, 9% of pancreatic tumors, 6% of parathyroid tumors, 5% of thyroid tumors, 6% of soft tissue tumors, and 4% of colorectal cancers. Mutations have also been reported in 45% of fibrous dysplasia of bone and is used to distinguish this condition from ossifying fibroma. Testing for GNAS mutations can aid in targeted drug therapy decisions.
Peripheral blood: 5 mL in EDTA tube. Bone marrow: 2 mL in EDTA tube. FFPE tissue: Paraffin block is preferred. Alternatively, send 1 H&E slide plus 5-10 unstained slides cut at 5 or more microns. Please use positively-charged slides and 10% NBF fixative. Do not use zinc fixatives. Fresh tissue: 0.5 - 1 cm3 in RPMI.
Use cold pack for transport, making sure cold pack is not in direct contact with specimen.