chr1-236686737-C-T

Variant names:

• chr1-236686737-C-T
• rs1553295414
• NM_001103.4:c.64C>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001103.4(ACTN2):​c.64C>T​(p.Gln22*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. 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. Q22Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ACTN2 NM_001103.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.13
• Publications: 0 publications found

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)

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 21 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001103.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	NM_001103.4	MANE Select	c.64C>T	p.Gln22*	stop_gained	Exon 1 of 21	NP_001094.1
	ACTN2	NM_001278343.2		c.64C>T	p.Gln22*	stop_gained	Exon 1 of 21	NP_001265272.1
	ACTN2	NR_184402.1		n.239C>T		non_coding_transcript_exon	Exon 1 of 23

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	ENST00000366578.6	TSL:1 MANE Select	c.64C>T	p.Gln22*	stop_gained	Exon 1 of 21	ENSP00000355537.4
	ACTN2	ENST00000542672.7	TSL:1	c.64C>T	p.Gln22*	stop_gained	Exon 1 of 21	ENSP00000443495.1
	ACTN2	ENST00000682015.1		c.64C>T	p.Gln22*	stop_gained	Exon 1 of 20	ENSP00000506961.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1407952 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 700496

African (AFR) AF: 0.00 AC: 0 AN: 29088

American (AMR) AF: 0.00 AC: 0 AN: 39326

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24202

East Asian (EAS) AF: 0.00 AC: 0 AN: 33838

South Asian (SAS) AF: 0.00 AC: 0 AN: 80966

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52714

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5480

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1084808

Other (OTH) AF: 0.00 AC: 0 AN: 57530

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA Uncertain:1

Nov 17, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. ClinVar contains an entry for this variant (Variation ID: 463213). This variant has not been reported in the literature in individuals affected with ACTN2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln22*) in the ACTN2 gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in ACTN2 cause disease.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	45
DANN	Uncertain	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.1
Vest4		0.73
GERP RS		3.8
PromoterAI		-0.030	Neutral
Mutation Taster		=3/197	disease causing (fs/PTC)

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

Other links and lift over

dbSNP: rs1553295414; hg19: chr1-236850037;