Peripheral nerve sheath tumors from patients with neurofibromatosis type 1 do not have the chromosomal translocation t(X;18).
Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder that is caused by a mutation in the NF1 gene. Hallmark characteristics include dermal neurofibromas, café-au-lait spots, and learning disabilities. In approximately 25% of NF1 cases, plexiform neurofibromas, or peripheral nerve sheath tumors (PNSTs) that involve large segments of nerve sheath and nerve root, can form, of which a small percentage become malignant (MPNST). Most MPNSTs are composed of spindled neoplastic cells, and they can resemble other spindle-cell sarcomas, including leiomyosarcoma and monophasic synovial sarcoma. Histological diagnosis of MPNST is not always straightforward, and various immunohistochemical and molecular adjuncts can be critical in establishing a correct diagnosis. One example of genetic testing is the assay for the t(X;18) chromosomal translocation, which has been found to be common in synovial sarcomas. The aim of this study was to determine whether MPNSTs contain the t(X;18) chromosomal translocation. To detect the t(X;18) translocation product, SYT-SSX, total RNA was extracted from frozen archival tumors (15 dermal neurofibromas, 4 plexiform neurofibromas, and 7 MPNSTs) using Trizol. The RNA was then subjected to reverse-transcriptase polymerase chain reaction (RT-PCR) to specifically amplify SYT-SSX. None of the dermal neurofibromas, plexiform neurofibromas, or MPNSTs analyzed were positive for SYT-SSX mRNA. The results indicate that the t(X;18) translocation is absent in neurofibromas and is not a marker for MPNST in patients with NF1.
Liew
Michael A
MA
Department of Pediatrics, Division of Medical Genetics, University of Utah, 50 North Medical Drive, Salt Lake City, UT 84132, USA.
Coffin
Cheryl M
CM
Fletcher
Jonathan A
JA
Hang
Minh-Thu N
MT
Tanito
Katsumi
K
Niimura
Michihito
M
Viskochil
David
D
D014408:Biomarkers, Tumor / Q000032:analysis; D002887:Chromosomes, Human, Pair 18; D006801:Humans; D018317:Nerve Sheath Neoplasms / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D009456:Neurofibromatosis 1 / Q000150:complications / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured; D014960:X Chromosome
D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C116512:SYT-SSX fusion protein