IndraLab

"Four additional cases were tested by whole transcriptome sequencing, showing an FN1-ACVR2A transcript in all cases, including 3 synovial chondromatosis and 1 synovial chondrosarcoma."

"Moreover, our results showed that 56% (15 of 27) of the cases were positive for FN1-ACVR2A fusion, significantly higher than the 19% reported by Amary et al. None of the cases in our study showed only ACVR2A gene rearrangement with no FN1 gene rearrangement."

"Studies using cell proliferation assays have differed on the extent of DNA aneuploidy seen in synovial chondromatosis. xref , xref An FN1-ACVR2A in-frame gene fusion was initially identified in one case each of synovial osteochondromatosis and synovial chondrosarcoma, during a genomic investigation of various benign and malignant cartilaginous neoplasms. xref In a more recent study, Amary et al. further confirmed these findings using FISH analysis and whole-transcriptome RNA sequencing on a large number of cases, showing that 57% of synovial chondromatosis harbored FN1 and/or ACVR2A gene rearrangements. xref Of the 7 synovial chondrosarcomas included in their study, only 4 were informative by FISH, showing evidence of FN1 and/or the ACVR2A gene rearrangements in 3 cases. xref "

"The high incidence of FN1-ACVR2A gene fusions in synovial osteochondromatosis is reported [ xref , xref ]."

"In this study we investigate a large cohort of synovial chondromatosis for the prevalence of the FN1-ACVR2A fusion."

"Results showed that FN1 and /or ACVR2A gene rearrangements were noted in 18 cases (67%), with an FN1-ACVR2A fusion being confirmed in 15 (56%) cases."

"FN1-ACVR2A gene fusions have been recently identified in synovial chondromatosis. xref , xref It was first reported by Totoki et al. xref who investigated chondrosarcomas by whole genome sequencing and found a single case of synovial chondrosarcoma with an FN1 - ACVR2A gene fusion."

"As this lesion harbored a previously unreported gene fusion, we attempted to establish its recurrent potential vis-à-vis the more common FN1-ACVR2A fusion."

"Both these entities are characterized by FN1-ACVR2A and ACVR2A-FN1 fusions [ xref ], which are present in at least 50% of synovial chondromatosis."

"FN1-ACVR2A gene fusion seen in 67% of synovial chondromatosis."