rs199476155

Variant names:

• chr9-35684493-T-TTC
• rs199476155
• NM_003289.4:c.696_697insGA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_003289.4(TPM2):​c.696_697insGA​(p.Lys233GlufsTer25) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TPM2 NM_003289.4 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.489
• Publications: 0 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: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM2	NM_003289.4	c.696_697insGA	p.Lys233GlufsTer25	frameshift_variant	Exon 7 of 9	ENST00000645482.3	NP_003280.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM2	ENST00000645482.3	c.696_697insGA	p.Lys233GlufsTer25	frameshift_variant	Exon 7 of 9		NM_003289.4	ENSP00000496494.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.49

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs199476155; hg19: chr9-35684490;