NM_001615.4:c.104T>C

Variant names:

• chr2-73901415-T-C
• rs1461116147
• NM_001615.4:c.104T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_001615.4(ACTG2):​c.104T>C​(p.Ile35Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ACTG2 NM_001615.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.96
• Publications: 1 publications found

Genes affected

ACTG2 (HGNC:145): (actin gamma 2, smooth muscle) Actins are highly conserved proteins that are involved in various types of cell motility and in the maintenance of the cytoskeleton. Three types of actins, alpha, beta and gamma, have been identified in vertebrates. 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. This gene encodes actin gamma 2; a smooth muscle actin found in enteric tissues. Alternative splicing results in multiple transcript variants encoding distinct isoforms. Based on similarity to peptide cleavage of related actins, the mature protein of this gene is formed by removal of two N-terminal peptides.[provided by RefSeq, Dec 2010]

ACTG2 Gene-Disease associations (from GenCC):

• visceral myopathy 1

  Inheritance: AR, AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• familial visceral myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• megacystis-microcolon-intestinal hypoperistalsis syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_001615.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the ACTG2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 35 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 3.3487 (above the threshold of 3.09). Trascript score misZ: 4.3482 (above the threshold of 3.09). GenCC associations: The gene is linked to visceral myopathy 1, megacystis-microcolon-intestinal hypoperistalsis syndrome, familial visceral myopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.941

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001615.4. 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
	ACTG2	NM_001615.4	MANE Select	c.104T>C	p.Ile35Thr	missense	Exon 2 of 9	NP_001606.1	P63267-1
	ACTG2	NM_001199893.2		c.104T>C	p.Ile35Thr	missense	Exon 2 of 8	NP_001186822.1	P63267-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTG2	ENST00000345517.8	TSL:1 MANE Select	c.104T>C	p.Ile35Thr	missense	Exon 2 of 9	ENSP00000295137.3	P63267-1
	ACTG2	ENST00000409918.5	TSL:1	c.104T>C	p.Ile35Thr	missense	Exon 2 of 4	ENSP00000387182.1	B8ZZJ2
	ACTG2	ENST00000880128.1		c.104T>C	p.Ile35Thr	missense	Exon 2 of 10	ENSP00000550187.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251260 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000994

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461838 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 727222

⚠️ 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: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ 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.: 34

Alfa AF: 0.0000508 Hom.: 0

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Megacystis-microcolon-intestinal hypoperistalsis syndrome 5 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	27
DANN	Benign	0.84
DEOGEN2	Pathogenic	0.81	D
Eigen	Uncertain	0.20
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.72	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	M
PhyloP100		8.0
PrimateAI	Pathogenic	0.93	D
PROVEAN	Benign	-2.0	N
REVEL	Pathogenic	0.90
Sift4G	Uncertain	0.0090	D
Polyphen		0.010	B
Vest4		0.92
MutPred		0.84		Gain of disorder (P = 0.013)
MVP		1.0
MPC		2.1
ClinPred		0.90	D
GERP RS		3.9
Varity_R		0.80
gMVP		0.88
Mutation Taster		=76/24	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: rs1461116147; hg19: chr2-74128542;