1-236744703-G-C

Variant names:

• chr1-236744703-G-C
• rs773942709
• NM_001103.4:c.1333G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001103.4(ACTN2):​c.1333G>C​(p.Glu445Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E445K) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ACTN2 NM_001103.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.98
• 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):

• ACTN2-related cardiac and skeletal myopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: 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: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• intrinsic cardiomyopathy

  Inheritance: AD Classification: MODERATE Submitted by: Laboratory for Molecular Medicine
• 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: 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, 0.746

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	NM_001103.4	MANE Select	c.1333G>C	p.Glu445Gln	missense	Exon 12 of 21	NP_001094.1	P35609-1
	ACTN2	NM_001278343.2		c.1333G>C	p.Glu445Gln	missense	Exon 12 of 21	NP_001265272.1	P35609-2
	ACTN2	NR_184402.1		n.1705G>C		non_coding_transcript_exon	Exon 14 of 23

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	ENST00000366578.6	TSL:1 MANE Select	c.1333G>C	p.Glu445Gln	missense	Exon 12 of 21	ENSP00000355537.4	P35609-1
	ACTN2	ENST00000542672.7	TSL:1	c.1333G>C	p.Glu445Gln	missense	Exon 12 of 21	ENSP00000443495.1	P35609-2
	ACTN2	ENST00000879537.1		c.1444G>C	p.Glu482Gln	missense	Exon 13 of 22	ENSP00000549596.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461848 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727230

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

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: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.63
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.42	T
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Benign	0.041	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Uncertain	-0.18	T
MutationAssessor	Pathogenic	3.1	M
PhyloP100		10
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-2.2	N
REVEL	Uncertain	0.40
Sift	Uncertain	0.028	D
Sift4G	Uncertain	0.0070	D
Polyphen		0.99	D
Vest4		0.84
MutPred		0.55		Loss of ubiquitination at K443 (P = 0.0516)
MVP		0.74
MPC		0.79
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.43
gMVP		0.48
Mutation Taster		=230/70	polymorphism

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: rs773942709; hg19: chr1-236908003;