chr1-154167938-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM4PP5_Moderate

The NM_152263.4(TPM3):ā€‹c.857A>Cā€‹(p.Ter286SerextTer57) variant causes a stop lost, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,810 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (ā˜…).

Frequency

Genomes: not found (cov: 32)
Exomes š‘“: 0.0000034 ( 0 hom. )

Consequence

TPM3
NM_152263.4 stop_lost, splice_region

Scores

2
1
4

Clinical Significance

Likely pathogenic criteria provided, single submitter P:2O:2

Conservation

PhyloP100: 2.27
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM4
Stoplost variant in NM_152263.4 Downstream stopcodon found after 39 codons.
PP5
Variant 1-154167938-T-G is Pathogenic according to our data. Variant chr1-154167938-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 12447.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-154167938-T-G is described in Lovd as [Pathogenic]. Variant chr1-154167938-T-G is described in Lovd as [Pathogenic]. Variant chr1-154167938-T-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TPM3NM_152263.4 linkuse as main transcriptc.857A>C p.Ter286SerextTer57 stop_lost, splice_region_variant 10/10 ENST00000651641.1 NP_689476.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TPM3ENST00000651641.1 linkuse as main transcriptc.857A>C p.Ter286SerextTer57 stop_lost, splice_region_variant 10/10 NM_152263.4 ENSP00000498577 P1P06753-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.0000121
AC:
3
AN:
247130
Hom.:
0
AF XY:
0.0000223
AC XY:
3
AN XY:
134304
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000869
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461810
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
727212
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000112
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000756
ExAC
AF:
0.00000828
AC:
1

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:2Other:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Congenital myopathy 4B, autosomal recessive Pathogenic:1Other:1
not provided, no classification providedliterature onlyGeneReviews-- -
Pathogenic, no assertion criteria providedliterature onlyOMIMMar 01, 2008- -
Congenital myopathy with fiber type disproportion;C5829889:Congenital myopathy 4B, autosomal recessive Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 11, 2023This sequence change disrupts the translational stop signal of the TPM3 mRNA. It is expected to extend the length of the TPM3 protein by 57 additional amino acid residues. This variant is present in population databases (rs199474720, gnomAD 0.009%). This protein extension has been observed in individuals with autosomal recessive nemaline myopathy and congenital fiber type disproportion (PMID: 12196661, 19953533). ClinVar contains an entry for this variant (Variation ID: 12447). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this protein extension affects TPM3 function (PMID: 12196661, 21357678). This variant results in an extension of the TPM3 protein. Other variant(s) that result in a similarly extended protein product (p.*286Lysext*57) have been observed in individuals with TPM3-related disease (PMID: 33124102). This suggests that these extensions may be clinically significant. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not provided Other:1
not provided, no classification providedliterature onlyTPM3 homepage - Leiden Muscular Dystrophy pages-- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Benign
-0.24
CADD
Benign
15
DANN
Benign
0.83
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.81
FATHMM_MKL
Uncertain
0.93
D
MutationTaster
Benign
1.3e-14
A;A;A;A;A;A;A;A;A;A
Vest4
0.15
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs199474720; hg19: chr1-154140414; API