Fig. 1.

Localization of C9ORF72 probes. The three known C9ORF72 transcripts are visualized; the repeat expansion in C9ORF72 is represented by a red triangle and located in the promoter region of variant 2 (NM_018325.4) or in the first intron of variant 1 (NM_145005.6) and variant 3 (NM_001256054.2). Whereas variant 1 is predicted to result in a 222 amino acid long protein (exon 2–5, isoform b), variant 2 and variant 3 appear to result in 481 amino acid long proteins (exon 2–11, isoform a). For our TaqMan assays, probes were used targeting total C9ORF72 transcripts, variant 2, and variant 3 (green). Our digital molecular barcoding experiment contained probes for total C9ORF72 transcripts, variant 1, and variant 2 as well as probes that target the region between exon 1a and the expansion (transcripts containing intron 1a) and between exon 1b and exon 2 (transcripts containing intron 1b, purple)