Detection of novel UBTF::ATXN7L3 fusion gene. (A) Protein structures of wild-type UBTF, ATXN7L3, and UBTF::ATXN7L3 fusion (exon 17 type) are shown. UBTF exon 17 is rearranged to the 5′ untranslated region (UTR) of ATXN7L3 and encodes an in-frame chimeric fusion protein. Direct sequencing of a representative case (SJALL060150) is shown. (B) Immunoblotting showing wild-type UBTF (right second lane), ATXN7L3 (left third lane), and UBTF::ATXN7L3 fusion (exon 17 type, 4th lane) proteins. Protein lysate was collected from human embryonic kidney 293T cells with transient transfection of wild-type UBTF and ATXN7L3, and UBTF::ATXN7L3 fusion containing plasmids. All samples were run in the same gel. After transferring, the membrane was cut, probed with 2 different antibodies, and then the 2 halves scanned together. (C) The deleted UBTF regions detected by WGS are shown in black bars. (D) The schema of UBTF deletion and direct sequencing of a representative case (SJBALL020169) is shown. Nontemplated nucleotides are inserted at the breakpoint.