Titin Variants in Dilated Cardiomyopathy

TTN Transcript / Exon Structure & Truncating Variants in Cardiomyopathy Studies

Titin - Exon 18

Details for Exon 18 of the Titin gene - Sequence Coordinates, Associated Transcripts, Functional Data, Truncating Variants and Sequence.

The exon number is based on the LRG numbering, as recommended for clinical reporting.


The genomic coordinates of HG19 and Locus Reference Genomic (LRG) and the CDS coordinates of the Titin meta-transcript for exon 18 are displayed below.

HG19 Genomic Locus Reference Genomic Meta-Transcript
StartEnd StartEnd StartEnd
179,647,791 179,647,533 52,739 52,9972,842 3,100


Exon 18 occurs in the following Titin transcripts (the number indicates the exon rank of exon 18 in each transcript).

18 18 17 18 17 17 18

Functional Data

Region: This exon occurs in the near Z-disk region of the titin protein.

Domains: This exon codes for the following domain(s) - Ig-like 3.

PSI: The "proportion spliced-in" (an estimate of the percentage of TTN transcripts that incorporate this exon based on RNAseq data) is 100% in DCM (LV tissue of 84 end-stage patients) and 100% in GTEx (LV tissue of 105 samples from Genotype-Tissue Expression project). (See Ref. 1 for details)

Symmetry: This exon is assymmetric, i.e. the length of the exon is not a multiple of three and therefore removal of it will alter the reading frame.

1. A. M. Roberts, J. S. Ware, D. S. Herman et al. Integrated allelic, transcriptional, and phenomic dissection of the cardiac effects of titin truncations in health and disease. Sci. Transl. Med. 7, 270ra6 (2015).

Truncating Variants

The following TTN truncating variants affecting this exon have been described in major published studies (click on the study name for more details):

StudyCohortPatient IDVariant (CDS)Variant (protein)Variant Type
STM 2015DCM-ES20HS01530c.3100G>Ap.Val1034Metother splice site
STM 2015DCM-ES20SF01658c.3100G>Ap.Val1034Metother splice site
STM 2015DCM-ES20AH01746c.3100G>Ap.Val1034Metother splice site
STM 2015HEALTHY-IC14AG01422c.3100G>Ap.Val1034Metother splice site
STM 2015FHS5630c.3100G>Aother splice site
LMM 2014ALL-CASES68c.3034C>Tp.Arg1012Xnonsense


Size of Exon: 259 bases           Ensembl ID: ENSE00002288113


ATGC = coding sequence, ATGC = non-coding sequence