15-63064075-G-T

Variant names:

• chr15-63064075-G-T
• rs758506771
• NM_001018005.2:c.784G>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_001018005.2(TPM1):​c.784G>T​(p.Ala262Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,690 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TPM1 NM_001018005.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.50

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 3 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.22161904).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM1	NM_001018005.2	c.784G>T	p.Ala262Ser	missense_variant	Exon 9 of 10	ENST00000403994.9	NP_001018005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM1	ENST00000403994.9	c.784G>T	p.Ala262Ser	missense_variant	Exon 9 of 10	1	NM_001018005.2	ENSP00000385107.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461690 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727132

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.059
CardioboostCm	Benign	0.0073
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Uncertain	24
DANN	Benign	0.93
DEOGEN2	Uncertain	0.69	.;D;.;.;.;D
Eigen	Benign	-0.18
Eigen_PC	Benign	0.041
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.89	D;D;D;D;D;D
M_CAP	Benign	0.064	D
MetaRNN	Benign	0.22	T;T;T;T;T;T
MetaSVM	Uncertain	0.36	D
MutationAssessor	Benign	0.56	N;N;N;.;.;.
PROVEAN	Benign	-0.42	N;N;.;.;.;N
REVEL	Uncertain	0.47
Sift	Benign	0.57	T;T;.;.;.;T
Sift4G	Benign	0.42	T;T;.;.;.;T
Polyphen		0.0	.;B;B;.;.;.
Vest4		0.26
MutPred		0.54		Gain of disorder (P = 0.0432);Gain of disorder (P = 0.0432);Gain of disorder (P = 0.0432);Gain of disorder (P = 0.0432);.;.;
MVP		0.46
ClinPred		0.45	T
GERP RS		5.8
Varity_R		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs758506771; hg19: chr15-63356274;