rs1162449700

Variant summary

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

The NM_006440.5(TXNRD2):​c.77_83dupTGCGGGG​(p.Ala30GlyfsTer14) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000539 in 1,485,532 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G28G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000023 ( 0 hom. )

Consequence

TXNRD2
NM_006440.5 frameshift

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 0.829

Publications

0 publications found
Variant links:
Genes affected
TXNRD2 (HGNC:18155): (thioredoxin reductase 2) The protein encoded by this gene belongs to the pyridine nucleotide-disulfide oxidoreductase family, and is a member of the thioredoxin (Trx) system. Three thioredoxin reductase (TrxR) isozymes are found in mammals. TrxRs are selenocysteine-containing flavoenzymes, which reduce thioredoxins, as well as other substrates, and play a key role in redox homoeostasis. This gene encodes a mitochondrial form important for scavenging reactive oxygen species in mitochondria. It functions as a homodimer containing FAD, and selenocysteine (Sec) at the active site. Sec is encoded by UGA codon that normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, the Sec insertion sequence (SECIS) element, which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. Alternatively spliced transcript variants encoding different isoforms, including a few localized in the cytosol and some lacking the C-terminal Sec residue, have been found for this gene. [provided by RefSeq, Jun 2017]
COMT (HGNC:2228): (catechol-O-methyltransferase) Catechol-O-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine to catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. This O-methylation results in one of the major degradative pathways of the catecholamine transmitters. In addition to its role in the metabolism of endogenous substances, COMT is important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. COMT is found in two forms in tissues, a soluble form (S-COMT) and a membrane-bound form (MB-COMT). The differences between S-COMT and MB-COMT reside within the N-termini. Several transcript variants are formed through the use of alternative translation initiation sites and promoters. [provided by RefSeq, Sep 2008]
COMT Gene-Disease associations (from GenCC):
  • paroxysmal dyskinesia
    Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TXNRD2NM_006440.5 linkc.77_83dupTGCGGGG p.Ala30GlyfsTer14 frameshift_variant Exon 1 of 18 ENST00000400521.7 NP_006431.2 Q9NNW7-1
COMTNM_000754.4 linkc.-269_-268insCCCCGCA upstream_gene_variant ENST00000361682.11 NP_000745.1 P21964-1A0A140VJG8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TXNRD2ENST00000400521.7 linkc.77_83dupTGCGGGG p.Ala30GlyfsTer14 frameshift_variant Exon 1 of 18 1 NM_006440.5 ENSP00000383365.1 Q9NNW7-1
COMTENST00000361682.11 linkc.-269_-268insCCCCGCA upstream_gene_variant 1 NM_000754.4 ENSP00000354511.6 P21964-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152092
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000225
AC:
3
AN:
1333332
Hom.:
0
Cov.:
31
AF XY:
0.00000304
AC XY:
2
AN XY:
657536
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
26856
American (AMR)
AF:
0.00
AC:
0
AN:
29156
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23284
East Asian (EAS)
AF:
0.0000331
AC:
1
AN:
30234
South Asian (SAS)
AF:
0.00
AC:
0
AN:
74146
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
33202
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3922
European-Non Finnish (NFE)
AF:
0.00000189
AC:
2
AN:
1057196
Other (OTH)
AF:
0.00
AC:
0
AN:
55336
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00400497), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000329
AC:
5
AN:
152200
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74426
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41556
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.000414
AC:
2
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67978
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

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

Submissions by phenotype

Primary dilated cardiomyopathy Uncertain:1
Mar 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TXNRD2-related conditions. ClinVar contains an entry for this variant (Variation ID: 943569). 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. This sequence change creates a premature translational stop signal (p.Ala30Glyfs*14) in the TXNRD2 gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in TXNRD2 cause disease. -

Cardiovascular phenotype Uncertain:1
Mar 24, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.77_83dupTGCGGGG variant, located in coding exon 1 of the TXNRD2 gene, results from a duplication of TGCGGGG at nucleotide position 77, causing a translational frameshift with a predicted alternate stop codon (p.A30Gfs). The exact length of the frameshifted region is unclear, as the first few potential stop codons encountered in the shifted frame are TGAs, which could instead encode for selenocysteines in the context of this selenocysteine-containing protein (Gonzalez-Flores JN et al. Biomol Concepts, 2013 Aug;4:349-65). Regardless of the length of the frameshifted region, this alteration is expected to result in premature protein truncation or nonsense-mediated mRNA decay. However, loss of function of TXNRD2 has not been clearly established as a mechanism of disease. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.83
Mutation Taster
=15/185
disease causing (fs/PTC)

Splicing

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

Publications

Other links and lift over

dbSNP: rs1162449700; hg19: chr22-19929243; API