rs199517163

Positions:

• chr1-154171492-T-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_152263.4(TPM3):​c.567-4A>C variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,613,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: TPM3 NM_152263.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.01283
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.04

Genes affected

TPM3 (HGNC:12012): (tropomyosin 3) This gene encodes a member of the tropomyosin family of actin-binding proteins. Tropomyosins are dimers of coiled-coil proteins that provide stability to actin filaments and regulate access of other actin-binding proteins. Mutations in this gene result in autosomal dominant nemaline myopathy and other muscle disorders. This locus is involved in translocations with other loci, including anaplastic lymphoma receptor tyrosine kinase (ALK) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), which result in the formation of fusion proteins that act as oncogenes. There are numerous pseudogenes for this gene on different chromosomes. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TPM3	NM_152263.4	c.567-4A>C		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000651641.1	NP_689476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TPM3	ENST00000651641.1	c.567-4A>C		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant			NM_152263.4	ENSP00000498577	P1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151840 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 249568 Hom.: 0 AF XY: 0.0000369 AC XY: 5 AN XY: 135402

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000353

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.0000267 AC: 39 AN: 1461842 Hom.: 0 Cov.: 31 AF XY: 0.0000316 AC XY: 23 AN XY: 727230

Gnomad4 AFR exome AF: 0.00

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: 0.0000333

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151840 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74146

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000974 Hom.: 0

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Congenital myopathy with fiber type disproportion;C5829889:Congenital myopathy 4B, autosomal recessive Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 11, 2022

This sequence change falls in intron 5 of the TPM3 gene. It does not directly change the encoded amino acid sequence of the TPM3 protein. This variant is present in population databases (rs199517163, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with TPM3-related conditions. ClinVar contains an entry for this variant (Variation ID: 582310). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Congenital myopathy with fiber type disproportion Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Congenital myopathy 4B, autosomal recessive Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	18
DANN	Benign	0.82

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.013
dbscSNV1_RF	Benign	0.13
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.25		Position offset: -8

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

Publications

LitVar

Other links and lift over

dbSNP: rs199517163; hg19: chr1-154143968;