chr1-236717897-G-T

Variant names:

• chr1-236717897-G-T
• rs758034866
• NM_001103.4:c.166G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001103.4(ACTN2):​c.166G>T​(p.Gly56Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G56S) 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: 8.15
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACTN2	NM_001103.4	c.166G>T	p.Gly56Cys	missense_variant	Exon 2 of 21	ENST00000366578.6	NP_001094.1
ACTN2	NM_001278343.2	c.166G>T	p.Gly56Cys	missense_variant	Exon 2 of 21		NP_001265272.1
ACTN2	NR_184402.1	n.341G>T		non_coding_transcript_exon_variant	Exon 2 of 23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACTN2	ENST00000366578.6	c.166G>T	p.Gly56Cys	missense_variant	Exon 2 of 21	1	NM_001103.4	ENSP00000355537.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461860 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

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

American (AMR) AF: 0.00 AC: 0 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: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111992

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

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.71
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	.;D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.67	D;D
MetaSVM	Uncertain	0.23	D
MutationAssessor	Uncertain	2.8	M;M
PhyloP100		8.2
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-7.0	D;D
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	.;D
Vest4		0.51
MutPred		0.56		Loss of disorder (P = 0.0455);Loss of disorder (P = 0.0455);
MVP		0.91
MPC		1.6
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.96
gMVP		0.84
Mutation Taster		=29/71	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

Other links and lift over

dbSNP: rs758034866; hg19: chr1-236881197;