Single gene testing
Accurate identification of genetic abnormalities
In cases where comprehensive NGS analysis cannot be performed or the diagnosis is highly suspect, we also offer a variety of single-gene fluorescence in situ hybridization (FISH) tests to identify common genetic rearrangements in the genes EWSR1, USP6, TFE3, PDGFB, SS18, SYT, FUS, DDIT3, CHOP, FOXO1, FKHR, NR4A3, ETV6, ALK, and others.
In some cases, the genetic abnormality may be something other than a fusion, and testing is available to support these cases. One such abnormality is the ring and giant rod chromosomes derived from amplified sequences of chromosome bands 12q13-15, which include several amplified genes such as MDM2, CPM, CDK4, and TSPAN31. This analysis is specifically useful in diagnosing well-differentiated liposarcomas and may be useful in a small subset of low-grade osteosarcomas.
A Test in Focus
William Sukov, M.D., provides an overview of the MDM2 gene amplification assay — a test that looks for amplification of the MDM2 gene region on chromosome 12q. He reviews when this test should be ordered, how it compares to other test options, and how its results can affect patient care.
Point mutations and small insertions and deletions may also arise in some types of sarcomas. Desmoid-type fibromatosis is challenging to diagnosis histologically, but identification of mutations in CTNNB1 (also known as BCAT) can greatly improve the diagnostic accuracy. CTNNB1 mutations are also indicative of a higher recurrence rate, making this an important prognostic marker.