19-55132937-C-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_003283.6(TNNT1):​c.815G>A​(p.Arg272His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000811 in 1,603,784 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. R272C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TNNT1
NM_003283.6 missense

Scores

5
9
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.55

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.26155338).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNT1NM_003283.6 linkc.815G>A p.Arg272His missense_variant Exon 14 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.815G>A p.Arg272His missense_variant Exon 14 of 14 1 NM_003283.6 ENSP00000467176.1 P13805-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152172
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000868
AC:
2
AN:
230508
AF XY:
0.00000803
show subpopulations
Gnomad AFR exome
AF:
0.0000700
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.00000551
AC:
8
AN:
1451494
Hom.:
0
Cov.:
31
AF XY:
0.00000694
AC XY:
5
AN XY:
720856
show subpopulations
African (AFR)
AF:
0.0000898
AC:
3
AN:
33408
American (AMR)
AF:
0.00
AC:
0
AN:
43088
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25764
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39404
South Asian (SAS)
AF:
0.0000119
AC:
1
AN:
83798
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51918
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.00000361
AC:
4
AN:
1108312
Other (OTH)
AF:
0.00
AC:
0
AN:
60048
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000328
AC:
5
AN:
152290
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74474
show subpopulations
African (AFR)
AF:
0.0000722
AC:
3
AN:
41550
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
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:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000827
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Nemaline myopathy 5 Uncertain:1
Jul 06, 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 histidine, which is basic and polar, at codon 272 of the TNNT1 protein (p.Arg272His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 1403279). 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"). 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
0.64
BayesDel_addAF
Uncertain
0.16
D
BayesDel_noAF
Uncertain
-0.010
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.32
.;.;.;T;T;.;.;.
Eigen
Uncertain
0.44
Eigen_PC
Uncertain
0.41
FATHMM_MKL
Benign
0.49
N
LIST_S2
Pathogenic
0.98
.;D;D;D;D;D;.;.
M_CAP
Pathogenic
0.56
D
MetaRNN
Benign
0.26
T;T;T;T;T;T;T;T
MetaSVM
Pathogenic
0.99
D
MutationAssessor
Uncertain
2.1
.;.;.;.;M;.;.;.
PhyloP100
2.5
PrimateAI
Uncertain
0.74
T
PROVEAN
Benign
-1.7
.;N;.;.;.;.;.;.
REVEL
Uncertain
0.57
Sift
Uncertain
0.0020
.;D;.;.;.;.;.;.
Sift4G
Uncertain
0.017
D;D;D;D;D;D;D;D
Polyphen
1.0
D;D;D;.;D;.;.;.
Vest4
0.31
MutPred
0.36
.;.;.;.;Gain of helix (P = 6e-04);.;.;.;
MVP
0.99
MPC
1.7
ClinPred
0.55
D
GERP RS
4.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.24
gMVP
0.21
Mutation Taster
=79/21
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs533424787; hg19: chr19-55644305; API