Fig. 1. Distribution of TTNtv in healthy individuals and DCM patients, and TTN exon usage in the heart. Distribution of TTNtv in healthy individuals and DCM patients, and TTN exon usage in the heart. A schematic of the TTN meta-transcript, with sarcomere regions demarcated. The meta-transcript (LRG_391_t1/ENST00000589042) is a manually curated, inferred complete transcript, incorporating all exons of all known TTN isoforms (including fetal and noncardiac isoforms) with the exception of the large alternative terminal exon 48 (dark green) that is unique to the novex-3 transcript (LRG_391_t2/ENST00000360870). Exon usage for the two principal adult cardiac isoforms, N2BA and N2B (ENST00000591111 and ENST00000460472), is shown, although exon usage in vivo is variable (see below). Novex-1 and novex-2 are rare cardiac isoforms that differ from N2B by the inclusion of a single unique exon each (red and blue, respectively, within the N2B track). Exon usage in human LV is depicted as the proportion spliced-in (PSI) (range, 0 to 1; gray bars): the proportion of transcripts that include a given exon. TTNtv are located more distally in cases compared with controls, with A-band and distal I-band enrichment in end-stage (n = 155) and unselected DCM patients (n = 374), and corresponding depletion in the population (n = 3603) and healthy volunteer (n = 308) cohorts. Angharad M. Roberts et al., Sci Transl Med 2015;7:270ra6 Copyright © 2015, American Association for the Advancement of Science