chr3-14135903-G-A

Position:

• chr3-14135903-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_024334.3(TMEM43):​c.877G>A​(p.Ala293Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A293E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TMEM43 NM_024334.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.70

Genes affected

TMEM43 (HGNC:28472): (transmembrane protein 43) This gene belongs to the TMEM43 family. Defects in this gene are the cause of familial arrhythmogenic right ventricular dysplasia type 5 (ARVD5), also known as arrhythmogenic right ventricular cardiomyopathy type 5 (ARVC5). Arrhythmogenic right ventricular dysplasia is an inherited disorder, often involving both ventricles, and is characterized by ventricular tachycardia, heart failure, sudden cardiac death, and fibrofatty replacement of cardiomyocytes. This gene contains a response element for PPAR gamma (an adipogenic transcription factor), which may explain the fibrofatty replacement of the myocardium, a characteristic pathological finding in ARVC. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM43	NM_024334.3	c.877G>A	p.Ala293Thr	missense_variant	10/12	ENST00000306077.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM43	ENST00000306077.5	c.877G>A	p.Ala293Thr	missense_variant	10/12	1	NM_024334.3	P1
TMEM43	ENST00000432444.2	c.*907G>A		3_prime_UTR_variant, NMD_transcript_variant	11/13	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 19, 2024

The c.877G>A (p.A293T) alteration is located in exon 10 (coding exon 10) of the TMEM43 gene. This alteration results from a G to A substitution at nucleotide position 877, causing the alanine (A) at amino acid position 293 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Arrhythmogenic right ventricular dysplasia 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 19, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 406894). This variant has not been reported in the literature in individuals affected with TMEM43-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 293 of the TMEM43 protein (p.Ala293Thr). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.058	T
BayesDel_noAF	Benign	-0.32
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	T
Eigen	Uncertain	0.24
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.80	T
M_CAP	Benign	0.019	T
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.2	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.51	T
PROVEAN	Uncertain	-2.5	N
REVEL	Benign	0.19
Sift	Uncertain	0.0090	D
Sift4G	Benign	0.081	T
Polyphen		0.63	P
Vest4		0.59
MutPred		0.77		Gain of relative solvent accessibility (P = 0.09);
MVP		0.44
MPC		0.13
ClinPred		0.90	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.23
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1060501357; hg19: chr3-14177403;