15-63042938-A-G

Variant names:

• chr15-63042938-A-G
• rs199476303
• NM_001018005.2:c.109A>G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_001018005.2(TPM1):​c.109A>G​(p.Lys37Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TPM1 NM_001018005.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 7.28

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 Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a region_of_interest Disordered (size 37) in uniprot entity TPM1_HUMAN there are 8 pathogenic changes around while only 0 benign (100%) 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM1	NM_001018005.2	c.109A>G	p.Lys37Glu	missense_variant	Exon 1 of 10	ENST00000403994.9	NP_001018005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM1	ENST00000403994.9	c.109A>G	p.Lys37Glu	missense_variant	Exon 1 of 10	1	NM_001018005.2	ENSP00000385107.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Jul 26, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This sequence change replaces lysine with glutamic acid at codon 37 of the TPM1 protein (p.Lys37Glu). The lysine residue is weakly conserved and there is a small physicochemical difference between lysine and glutamic acid. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with left ventricular noncompaction cardiomyopathy (PMID: 20965760). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 31897). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Other:1

Apr 15, 2012

Leiden Muscular Dystrophy (TPM1)

Significance: not provided

Review Status: no classification provided

Collection Method: curation

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
CardioboostCm	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	26
DANN	Uncertain	0.98
DEOGEN2	Benign	0.31	.;.;T;.;T;T;.;.;.;.;.
Eigen	Benign	-0.15
Eigen_PC	Benign	-0.053
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.95	D;D;D;.;D;D;D;T;T;T;D
M_CAP	Pathogenic	0.53	D
MetaRNN	Uncertain	0.43	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.65	D
MutationAssessor	Benign	1.5	L;L;.;.;L;.;L;L;L;L;.
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.85	N;N;.;N;N;N;N;N;N;.;.
REVEL	Uncertain	0.54
Sift	Benign	0.22	T;D;.;T;T;D;D;D;D;.;.
Sift4G	Benign	0.40	T;T;T;T;T;T;T;T;T;.;.
Polyphen		0.0010, 0.99, 0.025	.;.;.;.;B;D;.;.;.;B;.
Vest4		0.69
MutPred		0.19		Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);Loss of ubiquitination at K37 (P = 0.0027);
MVP		0.97
MPC		2.8
ClinPred		0.96	D
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.47
gMVP		0.83

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: rs199476303; hg19: chr15-63335137;