6-123366180-T-C

Variant names:

• chr6-123366180-T-C
• rs1040336692
• NM_006073.4:c.1276A>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_006073.4(TRDN):​c.1276A>G​(p.Thr426Ala) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T426P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TRDN NM_006073.4 missense, splice_region
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 1.02
• Publications: 0 publications found

Genes affected

TRDN (HGNC:12261): (triadin) This gene encodes an integral membrane protein found in skeletal and cardiac muscle. The encoded protein plays a role in skeletal muscle excitation-contraction coupling as part of the calcium release complex and is required for normal skeletal muscle strength. This protein indirectly links triads and microtubules in skeletal muscle. Mutations in this gene are associated with cardiac arrythmia syndrome and some variants in this gene may be associated with sudden cardiac death. [provided by RefSeq, May 2022]

TRDN Gene-Disease associations (from GenCC):

• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD, AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• catecholaminergic polymorphic ventricular tachycardia 5

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• familial long QT syndrome

  Inheritance: AR Classification: STRONG Submitted by: G2P
• long QT syndrome

  Inheritance: AR Classification: STRONG Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05627492).
• BP6: Variant 6-123366180-T-C is Benign according to our data. Variant chr6-123366180-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1507019.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TRDN	NM_006073.4	c.1276A>G	p.Thr426Ala	missense_variant, splice_region_variant	Exon 20 of 41	ENST00000334268.9	NP_006064.2
TRDN	NM_001251987.2	c.1279A>G	p.Thr427Ala	missense_variant, splice_region_variant	Exon 20 of 21		NP_001238916.1
TRDN	NM_001407315.1	c.1219A>G	p.Thr407Ala	missense_variant, splice_region_variant	Exon 19 of 20		NP_001394244.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TRDN	ENST00000334268.9	c.1276A>G	p.Thr426Ala	missense_variant, splice_region_variant	Exon 20 of 41	1	NM_006073.4	ENSP00000333984.5
TRDN	ENST00000662930.1	c.1279A>G	p.Thr427Ala	missense_variant, splice_region_variant	Exon 20 of 21			ENSP00000499585.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Catecholaminergic polymorphic ventricular tachycardia 1 Uncertain:1

Feb 09, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The alanine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has not been reported in the literature in individuals with TRDN-related conditions. This sequence change replaces threonine with alanine at codon 426 of the TRDN protein (p.Thr426Ala). The threonine residue is moderately conserved and there is a small physicochemical difference between threonine and alanine. This variant is not present in population databases (ExAC no frequency). -

Cardiovascular phenotype Benign:1

Apr 09, 2025

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.62
CADD	Benign	16
DANN	Benign	0.85
DEOGEN2	Benign	0.075	T
Eigen	Benign	-0.65
Eigen_PC	Benign	-0.45
FATHMM_MKL	Benign	0.57	D
LIST_S2	Benign	0.33	T
M_CAP	Benign	0.0063	T
MetaRNN	Benign	0.056	T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	0.55	N
PhyloP100		1.0
PrimateAI	Benign	0.33	T
PROVEAN	Benign	0.13	N
REVEL	Benign	0.011
Sift	Benign	0.55	T
Sift4G	Benign	0.76	T
Polyphen		0.0010	B
Vest4		0.054
MutPred		0.28		Loss of phosphorylation at T426 (P = 0.0245);
MVP		0.040
ClinPred		0.072	T
GERP RS		3.2
Varity_R		0.033
gMVP		0.0083
Mutation Taster		=94/6	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1040336692; hg19: chr6-123687325;