1-236739456-A-G
Variant summary
Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2
The NM_001103.4(ACTN2):āc.1031A>Gā(p.Asn344Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000743 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. 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. N344T) has been classified as Uncertain significance.
Frequency
Consequence
NM_001103.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -7 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
ACTN2 | NM_001103.4 | c.1031A>G | p.Asn344Ser | missense_variant | Exon 10 of 21 | ENST00000366578.6 | NP_001094.1 | |
ACTN2 | NM_001278343.2 | c.1031A>G | p.Asn344Ser | missense_variant | Exon 10 of 21 | NP_001265272.1 | ||
ACTN2 | NR_184402.1 | n.1403A>G | non_coding_transcript_exon_variant | Exon 12 of 23 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152134Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251472Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135914
GnomAD4 exome AF: 0.00000752 AC: 11AN: 1461888Hom.: 0 Cov.: 67 AF XY: 0.00000688 AC XY: 5AN XY: 727246
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152134Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74322
ClinVar
Submissions by phenotype
not provided Uncertain:1
p.Asn344Ser (c.1031A>G) in exon 10 of the ACTN2 gene (NM_001103.3; chr1-236902756-A-G) SCICD Classification: variant of uncertain significance based on limited data to associate this gene with disease and lack of case data. We do not feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). Gene-level evidence: ACTN2: We recently (2016) reviewed ACTN2's relationship with hypertrophic cardiomyopathy (HCM) in the ClinGen Cardiovascular Working Group and concluded that there is limited evidence supporting it as a disease gene for HCM. The ACNT2 gene encodes a muscle-specific alpha-actinin that is expressed in both skeletal and cardiac muscle. Alpha-actinin is localized in the Z-disc where it helps anchor myofibrillar actin filaments. Heterozygous variants in ACTN2 have been reported in associated with DCM, though they seem to represent only a small number of cases without strong segregation data or an animal model. LMM shared that they feel there is stronger evidence for ACTN2 as an HCM gene than DCM and for now they are handling these variants as ones of uncertain significance until more data is available. The Semsarian group has also reported ACTN2 as a putative HCM gene (Chiu et al 2010). In a family with HCM they found linkage to the ACTN2 locus with a LOD score of 2.82. Sequencing identified p.Ala119Thr in 7 affected family members in two generations. As such, ACTN2 remains a gene with unclear significance to HCM or DCM. Case data (not including our patient): ClinVar: not present Cases in the literature: none reported Segregation data: none reported Functional data: none reported In silico data (missense variants only): Per the test report, "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: "Benign"; Align- GVGD: "Class C45")." Conservation data: The asparagine at codon 344 is almost completely conserved across species (until zebrafish). Neighboring amino acids are completely conserved. Nearby pathogenic variants at this codon or neighboring codons: variant at the same codon (p.Asn344Thr) listed as variant of uncertain significance by Illumina clinical laboratories. Nearby variants are listed in ClinVar but are listed as variants of uncertain significance. Population data: Highest MAF in European (Finnish) population: 0.004484%. The variant was reported online in 1 of 123,130 individuals in the Genome Aggregation Consortium Dataset (gnomAD; http://gnomad.broadinstitute.org/), which currently includes variant calls on >140,000 unrelated individuals of African, Asian, European, Ashkenazi, Latino descent. Specifically, the variant was observed in 1 of 11,150 individuals of European (Finnish) descent (MAF=0.004484%). The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. Note that other variants with strong evidence for pathogenicity have been seen at similar frequencies in datasets like this so this does not necessarily rule out pathogenicity (Pan et al 2012). -
Cardiovascular phenotype Uncertain:1
The p.N344S variant (also known as c.1031A>G), located in coding exon 10 of the ACTN2 gene, results from an A to G substitution at nucleotide position 1031. The asparagine at codon 344 is replaced by serine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at