17-81511469-G-C

Variant names:

• chr17-81511469-G-C
• rs727504862
• NM_001614.5:c.521C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001614.5(ACTG1):​c.521C>G​(p.Ala174Gly) variant causes a missense change involving the alteration of a conserved nucleotide. 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A174T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ACTG1 NM_001614.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 9.51
• Publications: 1 publications found

Genes affected

ACTG1 (HGNC:144): (actin gamma 1) Actins are highly conserved proteins that are involved in various types of cell motility and in maintenance of the cytoskeleton. Three main groups of actin isoforms have been identified in vertebrate animals: alpha, beta, and gamma. The alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus. The beta and gamma actins co-exist in most cell types as components of the cytoskeleton and as mediators of internal cell motility. Actin gamma 1, encoded by this gene, is a cytoplasmic actin found in all cell types. Mutations in this gene are associated with DFNA20/26, a subtype of autosomal dominant non-syndromic sensorineural progressive hearing loss and also with Baraitser-Winter syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2017]

ACTG1 Gene-Disease associations (from GenCC):

• Baraitser-winter syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia
• nonsyndromic genetic hearing loss

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• autosomal dominant nonsyndromic hearing loss 20

  Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Baraitser-Winter cerebrofrontofacial syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.953

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACTG1	NM_001614.5	c.521C>G	p.Ala174Gly	missense_variant	Exon 4 of 6	ENST00000573283.7	NP_001605.1
ACTG1	NM_001199954.3	c.521C>G	p.Ala174Gly	missense_variant	Exon 4 of 6		NP_001186883.1
ACTG1	NR_037688.3	n.593C>G		non_coding_transcript_exon_variant	Exon 4 of 7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACTG1	ENST00000573283.7	c.521C>G	p.Ala174Gly	missense_variant	Exon 4 of 6	5	NM_001614.5	ENSP00000458435.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Dec 03, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Ala174Gly variant in ACTG1 has not been previously reported in individuals w ith hearing loss or in large population studies. Computational analyses (biochem ical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do not provide strong support for or against an impact to the protein. In summary, add itional data is needed to determine the clinical significance of this variant. -

Autosomal dominant nonsyndromic hearing loss 20;C3281235:Baraitser-winter syndrome 2 Uncertain:1

Apr 27, 2016

Division of Human Genetics, Children's Hospital of Philadelphia

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	26
DANN	Benign	0.96
DEOGEN2	Pathogenic	0.91	D;D;D;D;D;D;D;D;D
Eigen	Uncertain	0.22
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.77	.;.;T;.;.;.;T;.;T
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.5	M;M;M;M;M;M;.;.;.
PhyloP100		9.5
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.0	.;D;.;.;.;.;.;.;.
REVEL	Pathogenic	0.90
Sift4G	Uncertain	0.052	T;T;T;T;T;.;.;.;D
Polyphen		0.0010	B;B;B;B;B;B;.;.;.
Vest4		0.80
MutPred		0.80		Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);.;Gain of catalytic residue at A174 (P = 0.0265);Gain of catalytic residue at A174 (P = 0.0265);
MVP		0.93
ClinPred		0.98	D
GERP RS		4.6
Varity_R		0.97
gMVP		0.98
Mutation Taster		=3/97	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: rs727504862; hg19: chr17-79478495;