chr22-19877166-A-G

Position:

• chr22-19877166-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_006440.5(TXNRD2):​c.1514T>C​(p.Val505Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 11/19 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. V505D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TXNRD2 NM_006440.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.97

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.29681322).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TXNRD2	NM_006440.5	c.1514T>C	p.Val505Ala	missense_variant	17/18	ENST00000400521.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TXNRD2	ENST00000400521.7	c.1514T>C	p.Val505Ala	missense_variant	17/18	1	NM_006440.5	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1458284 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 725002

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary dilated cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2020

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. 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TXNRD2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with alanine at codon 505 of the TXNRD2 protein (p.Val505Ala). The valine residue is weakly conserved and there is a small physicochemical difference between valine and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.027	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Benign	0.33	.;.;.;.;.;T;.
Eigen	Benign	-0.084
Eigen_PC	Benign	-0.072
FATHMM_MKL	Benign	0.25	N
LIST_S2	Benign	0.79	.;T;.;.;.;T;.
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.30	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.24	D
MutationAssessor	Pathogenic	3.5	.;.;.;.;.;M;.
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.0	N;.;.;N;N;N;.
REVEL	Uncertain	0.46
Sift	Benign	0.032	D;.;.;D;D;D;.
Sift4G	Uncertain	0.050	T;D;D;T;T;T;D
Polyphen		0.14	.;.;.;.;.;B;.
Vest4		0.077
MutPred		0.64		.;.;.;.;.;Loss of methylation at K506 (P = 0.0424);.;
MVP		0.92
MPC		0.29
ClinPred		0.73	D
GERP RS		1.9
Varity_R		0.065

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr22-19864689;