Identification of ATP9A-NFATC2 gene fusion transcript in Behcet's disease, a subtype of uveitis

Fusion transcripts have been reported as biomarkers for several diseases; however, a fusion gene has not been reported in ophthalmic disease. To the best of our knowledge, the discovery of fusion transcript in Behcet's disease (BD), a noninfectious uveitis, is reported for the first time. We generated complete transcript data for BD subtape and discovered fusion transcripts specific to BD patients.

We sequenced total RNA from peripheral blood mononuclear cells isolated from clinically characterized BD patients and controls and generated BAM files, which served as input data for predicting fusion transcripts. We used Arriba, a computational tool for the detection of fusion transcripts. Arriba is fast and accurate for the identification of gene fusions from RNA sequencing data. It is specifically designed for high-throughput RNA-seq data, leveraging STAR-aligned chimeric BAM files to detect fusion events with high sensitivity.

The Arriba tool identified a set of fusion transcripts specific to BD patients. One of the fusion transcripts was characterized and validated, which represents the read-through fusion with a product size of 421 bp consisting of a part of exon 2 of NFATC2 (112bp) and a part of exon 28 of ATP9A (309 bp); these are adjacent genes in chromosome 20.

This paper reports the discovery of fusion transcript in uveitis-BD subtype and is also the first report for any ophthalmic disease. Such fusion transcript is absent in controls and other subtypes of uveitis. It may be a possible biomarker for the noninfectious BD patients.