rs757227738

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_003283.6(TNNT1):​c.535C>T​(p.Arg179Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000587 in 1,584,526 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R179Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)
Exomes 𝑓: 0.000063 ( 0 hom. )

Consequence

TNNT1
NM_003283.6 missense

Scores

14
4
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.23

Publications

2 publications found
Variant links:
Genes affected
TNNT1 (HGNC:11948): (troponin T1, slow skeletal type) This gene encodes a protein that is a subunit of troponin, which is a regulatory complex located on the thin filament of the sarcomere. This complex regulates striated muscle contraction in response to fluctuations in intracellular calcium concentration. This complex is composed of three subunits: troponin C, which binds calcium, troponin T, which binds tropomyosin, and troponin I, which is an inhibitory subunit. This protein is the slow skeletal troponin T subunit. Mutations in this gene cause nemaline myopathy type 5, also known as Amish nemaline myopathy, a neuromuscular disorder characterized by muscle weakness and rod-shaped, or nemaline, inclusions in skeletal muscle fibers which affects infants, resulting in death due to respiratory insufficiency, usually in the second year. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
TNNT1 Gene-Disease associations (from GenCC):
  • nemaline myopathy 5
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae)
  • nemaline myopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • nemaline myopathy 5C, autosomal dominant
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.906

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNT1NM_003283.6 linkc.535C>T p.Arg179Trp missense_variant Exon 11 of 14 ENST00000588981.6 NP_003274.3 P13805-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TNNT1ENST00000588981.6 linkc.535C>T p.Arg179Trp missense_variant Exon 11 of 14 1 NM_003283.6 ENSP00000467176.1 P13805-1

Frequencies

GnomAD3 genomes
AF:
0.0000134
AC:
2
AN:
148876
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.0000248
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:
0.0000148
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251066
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000634
AC:
91
AN:
1435650
Hom.:
0
Cov.:
33
AF XY:
0.0000588
AC XY:
42
AN XY:
713888
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32628
American (AMR)
AF:
0.00
AC:
0
AN:
43754
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25070
East Asian (EAS)
AF:
0.0000266
AC:
1
AN:
37594
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86022
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51458
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5634
European-Non Finnish (NFE)
AF:
0.0000795
AC:
87
AN:
1094986
Other (OTH)
AF:
0.0000342
AC:
2
AN:
58504
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
5
10
16
21
26
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000134
AC:
2
AN:
148876
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
72480
show subpopulations
African (AFR)
AF:
0.0000248
AC:
1
AN:
40362
American (AMR)
AF:
0.00
AC:
0
AN:
14788
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3456
East Asian (EAS)
AF:
0.00
AC:
0
AN:
4876
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4582
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10112
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000148
AC:
1
AN:
67452
Other (OTH)
AF:
0.00
AC:
0
AN:
2034
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000843
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Nemaline myopathy 5 Uncertain:2
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Mar 18, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 179 of the TNNT1 protein (p.Arg179Trp). This variant is present in population databases (rs757227738, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with TNNT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 465996). 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: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Uncertain
0.15
D
BayesDel_noAF
Pathogenic
0.15
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.89
.;.;.;D;D;.;.;.;.
Eigen
Uncertain
0.56
Eigen_PC
Uncertain
0.41
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Pathogenic
1.0
.;D;D;D;D;D;.;.;D
M_CAP
Pathogenic
0.63
D
MetaRNN
Pathogenic
0.91
D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Pathogenic
2.9
.;.;M;.;M;.;.;.;.
PhyloP100
1.2
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-7.3
.;D;D;.;.;.;.;.;.
REVEL
Pathogenic
0.79
Sift
Pathogenic
0.0
.;D;D;.;.;.;.;.;.
Sift4G
Pathogenic
0.0010
D;D;D;D;D;D;D;D;.
Polyphen
1.0
D;D;D;.;D;.;.;.;.
Vest4
0.73
MutPred
0.71
.;.;Loss of disorder (P = 6e-04);.;Loss of disorder (P = 6e-04);.;.;.;Loss of disorder (P = 6e-04);
MVP
1.0
MPC
0.74
ClinPred
0.98
D
GERP RS
3.0
PromoterAI
-0.049
Neutral
RBP_binding_hub_radar
0.92
RBP_regulation_power_radar
2.0
Varity_R
0.79
gMVP
0.58
Mutation Taster
=38/62
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs757227738; hg19: chr19-55648547; COSMIC: COSV52571531; COSMIC: COSV52571531; API