3-14135170-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PP3_Strong BS2

The NM_024334.3(TMEM43):c.718C>G(p.Arg240Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000205 in 1,460,132 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R240C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: TMEM43 NM_024334.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.83

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 0 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• BS2: High AC in GnomAdExome at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM43	NM_024334.3	c.718C>G	p.Arg240Gly	missense_variant	9/12	ENST00000306077.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM43	ENST00000306077.5	c.718C>G	p.Arg240Gly	missense_variant	9/12	1	NM_024334.3	P1
TMEM43	ENST00000432444.2	c.*748C>G		3_prime_UTR_variant, NMD_transcript_variant	10/13	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000240 AC: 6 AN: 249912 Hom.: 0 AF XY: 0.0000296 AC XY: 4 AN XY: 135196

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.000327

GnomAD4 exome AF: 0.0000205 AC: 30 AN: 1460132 Hom.: 0 Cov.: 32 AF XY: 0.0000220 AC XY: 16 AN XY: 726480

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000193

Gnomad4 NFE exome AF: 0.0000243

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 5 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Dec 13, 2023	This missense variant replaces arginine with glycine at codon 240 of the TMEM43 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TMEM43-related disorders in the literature. This variant has been identified in 6/249912 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 10, 2023	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 sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 240 of the TMEM43 protein (p.Arg240Gly). This variant is present in population databases (rs367910936, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with TMEM43-related conditions. ClinVar contains an entry for this variant (Variation ID: 1026428). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TMEM43 protein function. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.23
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.40	T
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.90	D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	-0.097	T
MutationAssessor	Pathogenic	3.5	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.71
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.85		Loss of methylation at R240 (P = 0.0444);
MVP		0.62
MPC		0.45
ClinPred		0.97	D
GERP RS		5.0
Varity_R		0.94
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs367910936; hg19: chr3-14176670;