rs397516370

Variant names:

• chr15-63057085-A-G
• rs397516370
• NM_001018005.2:c.341A>G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP2 PP3 PP5_Moderate

The NM_001018005.2(TPM1):​c.341A>G​(p.Glu114Gly) 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 Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TPM1 NM_001018005.2 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32

Genes affected

TPM1 (HGNC:12010): (tropomyosin 1) This gene is a member of the tropomyosin family of highly conserved, widely distributed actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Tropomyosin is composed of two alpha-helical chains arranged as a coiled-coil. It is polymerized end to end along the two grooves of actin filaments and provides stability to the filaments. The encoded protein is one type of alpha helical chain that forms the predominant tropomyosin of striated muscle, where it also functions in association with the troponin complex to regulate the calcium-dependent interaction of actin and myosin during muscle contraction. In smooth muscle and non-muscle cells, alternatively spliced transcript variants encoding a range of isoforms have been described. Mutations in this gene are associated with type 3 familial hypertrophic cardiomyopathy and dilated cardiomyopathy 1Y. [provided by RefSeq, Jun 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Tropomyosin alpha-1 chain (size 283) in uniprot entity TPM1_HUMAN there are 61 pathogenic changes around while only 1 benign (98%) in NM_001018005.2
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the TPM1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 42 curated pathogenic missense variants (we use a threshold of 10). The gene has 25 curated benign missense variants. Gene score misZ: 2.8677 (below the threshold of 3.09). Trascript score misZ: 3.9402 (above the threshold of 3.09). GenCC associations: The gene is linked to dilated cardiomyopathy, left ventricular noncompaction, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 3, arrhythmogenic right ventricular cardiomyopathy, familial isolated dilated cardiomyopathy, dilated cardiomyopathy 1Y.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.836
• PP5: Variant 15-63057085-A-G is Pathogenic according to our data. Variant chr15-63057085-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 43415.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr15-63057085-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM1	NM_001018005.2	c.341A>G	p.Glu114Gly	missense_variant	Exon 3 of 10	ENST00000403994.9	NP_001018005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM1	ENST00000403994.9	c.341A>G	p.Glu114Gly	missense_variant	Exon 3 of 10	1	NM_001018005.2	ENSP00000385107.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary dilated cardiomyopathy Pathogenic:1

Nov 14, 2011

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Glu114Gly variant (TPM1) has not been previously reported, but has been iden tified in 1 individual with DCM out of >2000 Caucasian probands tested by our la boratory. This low frequency supports a pathogenic role. In addition, glutamic a cid (Glu) is highly conserved across evolutionarily distant species, increasing the likelihood that a change would not be tolerated. Finally, this variant was p redicted to be pathogenic using a computational tool, which was validated by our laboratory using a set of cardiomyopathy variants with well-established clinica l significance. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). In summary, the Glu114Gly variant is likely to be pa thogenic, though segregation studies and functional analyses are required to est ablish this with certainty. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.55
CardioboostCm	Uncertain	0.83
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.17
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	.;.;D;D;.;.;.;.;.;.;D;.;.;.;D
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.88	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.69	D
MutationAssessor	Pathogenic	4.0	H;H;H;.;H;H;H;H;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-5.5	D;D;D;D;D;D;D;.;.;D;D;.;D;D;D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.018	D;D;D;D;D;D;D;.;.;D;D;.;D;D;D
Sift4G	Benign	0.063	T;T;T;T;T;T;T;.;.;D;D;.;D;D;D
Polyphen		0.13, 0.85, 0.014, 1.0	.;.;B;P;.;.;.;B;.;.;.;.;.;D;.
Vest4		0.79
MutPred		0.57		.;.;.;Gain of MoRF binding (P = 0.0607);.;.;.;.;.;.;.;.;.;.;.;
MVP		0.84
MPC		2.6
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.70
gMVP		0.98

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

Publications

LitVar

Other links and lift over

dbSNP: rs397516370; hg19: chr15-63349284;