chr1-236754025-C-T

Position:

chr1-236754025-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM5PP3BS2

The NM_001103.4(ACTN2):c.1918C>T(p.Arg640Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000142 in 1,614,142 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. R640H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

ACTN2
NM_001103.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 4.70

Variant links:

Genes affected

ACTN2 (HGNC:164): (actinin alpha 2) Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins. Alpha actinin is an actin-binding protein with multiple roles in different cell types. In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane. In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments. This gene encodes a muscle-specific, alpha actinin isoform that is expressed in both skeletal and cardiac muscles. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2013]

ACTN2 links:

ACTN2 (HGNC:):

ACTN2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-236754026-G-A is described in Lovd as [Likely_pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.834

BS2

High AC in GnomAdExome4 at 19 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACTN2	NM_001103.4 linkuse as main transcript	c.1918C>T	p.Arg640Cys	missense_variant	16/21	ENST00000366578.6	NP_001094.1	P35609-1
ACTN2	NM_001278343.2 linkuse as main transcript	c.1918C>T	p.Arg640Cys	missense_variant	16/21		NP_001265272.1	P35609-2
ACTN2	NR_184402.1 linkuse as main transcript	n.2290C>T		non_coding_transcript_exon_variant	18/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACTN2	ENST00000366578.6 linkuse as main transcript	c.1918C>T	p.Arg640Cys	missense_variant	16/21	1	NM_001103.4	ENSP00000355537.4		P35609-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152220

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251188

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135850

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461804

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727204

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152338

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74502

show subpopulations

Gnomad4 AFR

AF:

0.0000240

Gnomad4 AMR

AF:

0.0000653

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000941

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000825

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 14, 2023

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 640 of the ACTN2 protein (p.Arg640Cys). This variant is present in population databases (rs769453411, gnomAD 0.006%). This missense change has been observed in individual(s) with clinical features of ACTN2-related conditions (PMID: 26688388, 29247119). ClinVar contains an entry for this variant (Variation ID: 296507). 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 not expected to disrupt ACTN2 protein function with a negative predictive value of 80%. 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. -

Dilated cardiomyopathy 1AA

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Dilated cardiomyopathy 1AA;C5203349:Myopathy, distal, 6, adult-onset, autosomal dominant;C5231445:Myopathy, congenital, with structured cores and z-line abnormalities

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 20, 2021

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 24, 2023

Reported in an individual with DCM and an individual with sudden unexplained death (Chanavat et al., 2016; Lin et al., 2017); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Reported in ClinVar as a variant of uncertain significance (ClinVar Variant ID# 296507; ClinVar); This variant is associated with the following publications: (PMID: 29247119, 26688388) -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 30, 2022

The p.R640C variant (also known as c.1918C>T), located in coding exon 16 of the ACTN2 gene, results from a C to T substitution at nucleotide position 1918. The arginine at codon 640 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration has been reported in sudden death cohorts; however, clinical details were limited (Chanavat V et al. Clin Chim Acta, 2016 Jan;453:80-5; Lin Y et al. Circ Cardiovasc Genet, 2017 Dec;10:[ePub ahead of print]). Additionally, this variant was detected in a cardiomyopathy genetic testing cohort; however, clinical details were limited, and additional cardiac variants were detected in some cases (van Lint FHM et al. Neth Heart J, 2019 Jun;27:304-309). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Pathogenic

0.15

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.58

.;.;D

Eigen

Pathogenic

0.76

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.94

D;D;D

M_CAP

Benign

0.059

MetaRNN

Pathogenic

0.83

D;D;D

MetaSVM

Benign

-0.38

MutationAssessor

Uncertain

2.6

.;M;M

PrimateAI

Pathogenic

0.83

PROVEAN

Pathogenic

-4.8

.;D;D

REVEL

Uncertain

0.36

Sift

Uncertain

0.0010

.;D;D

Sift4G

Uncertain

0.010

D;D;D

Polyphen

1.0

.;.;D

Vest4

0.85

MVP

0.82

MPC

0.91

ClinPred

1.0

GERP RS

5.4

Varity_R

0.65

gMVP

0.61

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over