rs878854363

Variant names:

• chr9-35689205-A-G
• rs878854363
• NM_003289.4:c.181T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP2 PP3_Moderate PP5

The NM_003289.4(TPM2):​c.181T>C​(p.Ser61Pro) 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TPM2 NM_003289.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.56
• Publications: 1 publications found

Genes affected

TPM2 (HGNC:12011): (tropomyosin 2) This gene encodes beta-tropomyosin, a member of the actin filament binding protein family, and mainly expressed in slow, type 1 muscle fibers. Mutations in this gene can alter the expression of other sarcomeric tropomyosin proteins, and cause cap disease, nemaline myopathy and distal arthrogryposis syndromes. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2009]

TPM2 Gene-Disease associations (from GenCC):

• TPM2-related myopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• arthrogryposis, distal, type 1A

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• congenital myopathy 23

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• congenital myopathy

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• cap myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• childhood-onset nemaline myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital fiber-type disproportion myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• digitotalar dysmorphism

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Sheldon-hall syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• typical nemaline myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a region_of_interest Disordered (size 64) in uniprot entity TPM2_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_003289.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the TPM2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 19 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 2.1346 (below the threshold of 3.09). Trascript score misZ: 3.2995 (above the threshold of 3.09). GenCC associations: The gene is linked to cap myopathy, arthrogryposis, distal, type 1A, typical nemaline myopathy, TPM2-related myopathy, Sheldon-hall syndrome, congenital fiber-type disproportion myopathy, congenital myopathy, congenital myopathy 23, digitotalar dysmorphism, childhood-onset nemaline myopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.846
• PP5: Variant 9-35689205-A-G is Pathogenic according to our data. Variant chr9-35689205-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 224658.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM2	NM_003289.4	c.181T>C	p.Ser61Pro	missense_variant	Exon 2 of 9	ENST00000645482.3	NP_003280.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM2	ENST00000645482.3	c.181T>C	p.Ser61Pro	missense_variant	Exon 2 of 9		NM_003289.4	ENSP00000496494.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Congenital myopathy 23 Pathogenic:1

Dec 01, 2015

Center for Genetic Medicine Research, Children's National Medical Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Arthrogryposis, distal, type 1A Uncertain:1

May 08, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has been observed in individual(s) with congenital fiber type disproportion (PMID: 22832343). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 224658). This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with proline at codon 61 of the TPM2 protein (p.Ser61Pro). The serine residue is moderately conserved and there is a moderate physicochemical difference between serine and proline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.78	.;D;.;D;D;D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.91	.;D;D;.;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Pathogenic	3.3	M;.;M;M;M;.
PhyloP100		7.6
PrimateAI	Uncertain	0.79	T
PROVEAN	Uncertain	-2.4	N;N;D;.;N;.
REVEL	Pathogenic	0.78
Sift	Uncertain	0.013	D;D;D;.;D;.
Sift4G	Benign	0.17	T;T;T;.;T;.
Polyphen		0.76	P;.;P;D;D;P
Vest4		0.79
MutPred		0.59		Loss of phosphorylation at S61 (P = 0.008);Loss of phosphorylation at S61 (P = 0.008);Loss of phosphorylation at S61 (P = 0.008);Loss of phosphorylation at S61 (P = 0.008);Loss of phosphorylation at S61 (P = 0.008);Loss of phosphorylation at S61 (P = 0.008);
MVP		0.97
MPC		2.3
ClinPred		0.97	D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.64
gMVP		0.99
Mutation Taster		=11/89	disease causing (ClinVar)

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: rs878854363; hg19: chr9-35689202;