22-19941720-G-GCCCCGCA

Variant names:

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]

TXNRD2 links:

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

COMT links:

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
TXNRD2	NM_006440.5 link	c.77_83dupTGCGGGG	p.Ala30GlyfsTer14	frameshift_variant	Exon 1 of 18	ENST00000400521.7	NP_006431.2	Q9NNW7-1
COMT	NM_000754.4 link	c.-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
TXNRD2	ENST00000400521.7 link	c.77_83dupTGCGGGG	p.Ala30GlyfsTer14	frameshift_variant	Exon 1 of 18	1	NM_006440.5	ENSP00000383365.1		Q9NNW7-1
COMT	ENST00000361682.11 link	c.-269_-268insCCCCGCA		upstream_gene_variant		1	NM_000754.4	ENSP00000354511.6		P21964-1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152092

Hom.:

Cov.:

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:

AN:

1333332

Hom.:

Cov.:

AF XY:

0.00000304

AC XY:

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:

AN:

26856

American (AMR)

AF:

0.00

AC:

AN:

29156

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

23284

East Asian (EAS)

AF:

0.0000331

AC:

AN:

30234

South Asian (SAS)

AF:

0.00

AC:

AN:

74146

European-Finnish (FIN)

AF:

0.00

AC:

AN:

33202

Middle Eastern (MID)

AF:

0.00

AC:

AN:

3922

European-Non Finnish (NFE)

AF:

0.00000189

AC:

AN:

1057196

Other (OTH)

AF:

0.00

AC:

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

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74426

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41556

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5162

South Asian (SAS)

AF:

0.000414

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67978

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

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)

(source)

Splicing

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over