Targeted RNA-sequencing identifies FBXW4 instead of MGEA5 as fusion partner of TGFBR3 in pleomorphic hyalinizing angiectatic tumor.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare mesenchymal tumor of intermediate malignancy. PHAT, and the related hemosiderotic fibrolipomatous tumor, show a recurrent t(1;10)(p22;q24). Fluorescence in situ hybridization (FISH) and BAC (bacterial artificial chromosome) clones have previously identified TGFBR3 and MGEA5 as fusion partners. However, targeted RNA-sequencing allowed for the correct identification of FBXW4 and not MGEA5 as the fusion partner of TGFBR3 in a subcutaneous PHAT, a finding further confirmed by RT-PCR. FBXW4 and MGEA5 share a common cytogenetic location at 10q24.32, thereby suggesting that the use of less precise technology may have led to inaccurate gene identification. The study of additional cases is however required.