rs779112211

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM5BP4_Strong

The NM_003283.6(TNNT1):​c.725C>T​(p.Ala242Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,612,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict 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. A242P) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 30)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

TNNT1
NM_003283.6 missense

Scores

1
6
12

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.47

Publications

1 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.

PM5
Other missense variant is known to change same aminoacid residue: Variant chr19-55134092-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2503499.Status of the report is no_assertion_criteria_provided, 0 stars.
BP4
Computational evidence support a benign effect (MetaRNN=0.06588158).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNT1NM_003283.6 linkc.725C>T p.Ala242Val missense_variant Exon 12 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.725C>T p.Ala242Val missense_variant Exon 12 of 14 1 NM_003283.6 ENSP00000467176.1 P13805-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152162
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000771
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000403
AC:
10
AN:
248046
AF XY:
0.0000446
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000545
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1460526
Hom.:
0
Cov.:
36
AF XY:
0.0000165
AC XY:
12
AN XY:
726466
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44598
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26088
East Asian (EAS)
AF:
0.000428
AC:
17
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85986
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52776
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111788
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
2
4
5
7
9
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:
0.0000591
AC:
9
AN:
152280
Hom.:
0
Cov.:
30
AF XY:
0.0000537
AC XY:
4
AN XY:
74460
show subpopulations
African (AFR)
AF:
0.0000722
AC:
3
AN:
41560
American (AMR)
AF:
0.0000654
AC:
1
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000773
AC:
4
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.000473
AC:
1
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000237
Hom.:
0
Bravo
AF:
0.000110
ExAC
AF:
0.0000577
AC:
7

ClinVar

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

Submissions by phenotype

Nemaline myopathy 5 Uncertain:1
Sep 07, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 242 of the TNNT1 protein (p.Ala242Val). This variant is present in population databases (rs779112211, gnomAD 0.05%). 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: 534402). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.23
CADD
Benign
18
DANN
Benign
0.97
DEOGEN2
Uncertain
0.43
.;.;.;T;T;.;.;.
Eigen
Benign
-0.85
Eigen_PC
Benign
-0.98
FATHMM_MKL
Benign
0.45
N
LIST_S2
Uncertain
0.97
.;D;D;D;D;D;.;.
M_CAP
Uncertain
0.099
D
MetaRNN
Benign
0.066
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.63
T
MutationAssessor
Benign
0.0
.;.;.;.;N;.;.;.
PhyloP100
1.5
PrimateAI
Uncertain
0.49
T
PROVEAN
Benign
-0.84
.;N;.;.;.;.;.;.
REVEL
Uncertain
0.33
Sift
Pathogenic
0.0
.;D;.;.;.;.;.;.
Sift4G
Uncertain
0.056
T;T;D;T;D;T;T;T
Polyphen
0.87
P;P;P;.;P;.;.;.
Vest4
0.34
MVP
0.70
MPC
0.85
ClinPred
0.11
T
GERP RS
-8.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.14
gMVP
0.15
Mutation Taster
=84/16
polymorphism

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

Other links and lift over

dbSNP: rs779112211; hg19: chr19-55645459; API