1-236755022-A-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_001103.4(ACTN2):​c.1978A>T​(p.Ile660Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,876 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 (★). Synonymous variant affecting the same amino acid position (i.e. I660I) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

ACTN2
NM_001103.4 missense

Scores

3
13
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.43

Publications

1 publications found
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 Gene-Disease associations (from GenCC):
  • intrinsic cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Laboratory for Molecular Medicine, ClinGen
  • myopathy, congenital, with structured cores and z-line abnormalities
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • dilated cardiomyopathy 1AA
    Inheritance: AD Classification: MODERATE, LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • heart conduction disease
    Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp
  • myopathy, distal, 6, adult-onset, autosomal dominant
    Inheritance: AD, Unknown Classification: LIMITED Submitted by: Broad Center for Mendelian Genomics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.839

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ACTN2NM_001103.4 linkc.1978A>T p.Ile660Phe missense_variant Exon 17 of 21 ENST00000366578.6 NP_001094.1 P35609-1
ACTN2NM_001278343.2 linkc.1978A>T p.Ile660Phe missense_variant Exon 17 of 21 NP_001265272.1 P35609-2
ACTN2NR_184402.1 linkn.2350A>T non_coding_transcript_exon_variant Exon 19 of 23

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ACTN2ENST00000366578.6 linkc.1978A>T p.Ile660Phe missense_variant Exon 17 of 21 1 NM_001103.4 ENSP00000355537.4 P35609-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251468
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461876
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112002
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA Uncertain:1
Sep 27, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, this variant is a rare missense change with uncertain impact on protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C15"). This variant is present in population databases (rs768670466, ExAC 0.02%) but has not been reported in the literature in individuals with an ACTN2-related disease. This sequence change replaces isoleucine with phenylalanine at codon 660 of the ACTN2 protein (p.Ile660Phe). The isoleucine residue is highly conserved and there is a small physicochemical difference between isoleucine and phenylalanine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.47
BayesDel_addAF
Uncertain
0.016
T
BayesDel_noAF
Uncertain
-0.040
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.54
.;.;D
Eigen
Uncertain
0.66
Eigen_PC
Uncertain
0.60
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.98
D;D;D
M_CAP
Benign
0.037
D
MetaRNN
Pathogenic
0.84
D;D;D
MetaSVM
Benign
-0.36
T
MutationAssessor
Uncertain
2.6
.;M;M
PhyloP100
7.4
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-3.3
.;D;D
REVEL
Uncertain
0.43
Sift
Uncertain
0.0010
.;D;D
Sift4G
Uncertain
0.020
D;D;D
Polyphen
0.96
.;.;D
Vest4
0.81
MutPred
0.71
.;Loss of MoRF binding (P = 0.1067);Loss of MoRF binding (P = 0.1067);
MVP
0.68
MPC
0.92
ClinPred
0.98
D
GERP RS
4.6
Varity_R
0.78
gMVP
0.75
Mutation Taster
=15/85
disease causing

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

Other links and lift over

dbSNP: rs768670466; hg19: chr1-236918322; API