Multiple MYO18A-PDGFRB fusion transcripts in a myeloproliferative neoplasm patient with t(5;17)(q32;q11).

Abstract

BACKGROUND:

Myeloproliferative neoplasms (MPNs), typically defined by myeloid proliferation and eosinophilia, and are only rarely caused by platelet-derived growth factor receptor beta (PDGFRB) gene rearrangements.

CASE PRESENTATION:

Here, we report a unique case of MPN that is negative for eosinophilia and characterized by a novel PDGFRB rearrangement. After cytogenetic analysis revealed a karyotype of t(5;17) (q32;q11), we used fluorescence in situ hybridization to specifically identify the PDGFRB gene at 5q31-q33 as the gene that had been translocated. Subsequently, RNA sequencing identified a new MYO18A-PDGFRB gene fusion. This fusion presented a previously undescribed breakpoint composed of exon 37 of MYO18A and exon 13 of PDGFRB. Furthermore, both RT-PCR and Bi-directional Sanger sequencing confirmed this out-of-frame fusion. Interestingly, we simultaneously identified the presence of another three PDGFRB transcripts, all of which were in-frame fusions. After treating the patient with imatinib, the t(5;17) translocation was no longer detected by conventional cytogenetics or by FISH, and at the time of the last follow-up, the patient had been in complete remission for 26 months.

CONCLUSION:

We prove that MYO18A-PDGFRB fusions are recurrent genetic aberrations involved in MPNs, and identify multiple fusion transcripts with novel breakpoints.

• Authors: Guangying Sheng, Zhao Zeng, Jinlan Pan, Linbing Kou, Qinrong Wang, Hong Yao, Lijun Wen, Liang Ma, Depei Wu, Huiying Qiu, Suning Chen
• Journal: Molecular cytogenetics (Mol Cytogenet) Vol. 10 Pg. 4 ( 2017) ISSN: 1755-8166 [Print] England
• PMID: 28261327 (Publication Type: Case Reports)