Both Xp11.2 translocation renal cell carcinoma (RCC) and alveolar soft part sarcoma (ASPS) are characterized by various translocations disrupting chromosome Xp11.2, which result in gene fusions involving the TFE3 transcription factor gene. Diagnostic tools to detect translocations involving the TFE3 gene on chromosome X would be valuable in the evaluation of these tumors. We developed a dual-color, break-apart fluorescence in situ hybridization (FISH) assay to identify the chromosomal break point in paraffin-embedded tissue. This assay was validated using 4 cases of Xp11.2 RCC [proven by karyotype and/or reverse-transcriptase polymerase chain reaction (RT-PCR)], 2 cases of ASPS (proven by karyotype or RT-PCR), the UOK109 cell line carrying the inv(X) (p11;q12), and several negative controls (both neoplastic and non-neoplastic). This break-apart FISH assay is a relatively quick procedure for detecting Xp11.2 RCC and ASPS translocations and can be applied to archival paraffin-embedded tissue.
*Pathology and Laboratory Medicine
†Institute of Genomic Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark
‡Hackensack University Medical Center, Hackensack, NJ
§Mount Sinai School of Medicine New York, NY
∥Urologic Oncology Branch
¶Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD
Supported by NJMS pathology department resident research fund.
Correspondence: Minghao Zhong, MD, PhD and Meera Hameed, MD, Department of Pathology & Laboratory Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 01703 (e-mail: email@example.com; Hameedm@mskcc.org).