Titin Variants in Dilated Cardiomyopathy

TTN Transcript / Exon Structure & Truncating Variants in Cardiomyopathy Studies

Titin - Exon 249

Details for Exon 249 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.

Coordinates

The genomic coordinates of HG19 and Locus Reference Genomic (LRG) and the CDS coordinates of the Titin meta-transcript for exon 249 are displayed below.

HG19 Genomic HG38 Genomic Locus Reference Genomic Meta-Transcript
StartEnd StartEnd StartEnd StartEnd
179,485,352 179,484,944 178,620,625 178,620,217 215,178 215,58645,896 46,304

Transcripts

Exon 249 occurs in the following Titin transcripts (the number indicates the exon rank of exon 249 in each transcript).

METAN2BAN2BN2ANOVEX-1NOVEX-2NOVEX-3
248 198 76 197 77 77 -

Functional Data

Region: This exon occurs in the I-band region of the titin protein.

Domains: This exon codes for the following domain(s) - Ig-like 93/94.

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 96% 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.

References
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-ES20SG01639c.46236C>Ap.C15412*nonsense
LMM 2014ALL-CASES109c.46069_46070delATp.Met15357ValfsX4frameshift
NEJM 2012DCM-B UK-H11c.46236C>Ap.Cys15412Xnonsense

The shaded variants are from a cohort (DCM-B of the 2012 NEJM study) that was also included in the 2015 STM study (DCM-ES cohort) and therefore represent redundant mutations.

Sequence

Size of Exon: 409 bases           Ensembl ID: ENSE00002288463

AGGAAGACCTTAGGATTGTTGAGCCTCTTAAAGATATTGAAACAATGGAGAAGAAATCTGTCACATTCTGGTGCAAGGTGAATCGTCTCAATGTAACACTGAAGTGGACCAAAAATGGTG
AAGAAGTGCCTTTTGACAACCGTGTCTCATACAGAGTTGATAAGTACAAGCACATGTTAACCATTAAAGACTGTGGCTTCCCAGATGAAGGTGAATACATTGTCACTGCTGGACAAGATA
AATCTGTTGCTGAGCTTCTCATCATAGAAGCCCCGACAGAATTTGTGGAACACTTGGAAGATCAGACAGTCACTGAGTTCGATGACGCTGTCTTCTCCTGCCAGCTCTCCAGAGAGAAAG
CCAATGTAAAATGGTACAGAAATGGGAGAGAAATCAAAGAAGGCAAAAA

ATGC = coding sequence, ATGC = non-coding sequence