chr22-19895496-A-C

Position:

• chr22-19895496-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006440.5(TXNRD2):​c.860T>G​(p.Leu287Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,640 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: TXNRD2 NM_006440.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.36

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TXNRD2	NM_006440.5	c.860T>G	p.Leu287Arg	missense_variant	11/18	ENST00000400521.7	NP_006431.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TXNRD2	ENST00000400521.7	c.860T>G	p.Leu287Arg	missense_variant	11/18	1	NM_006440.5	ENSP00000383365.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000803 AC: 2 AN: 249160 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135206

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000479 AC: 7 AN: 1461640 Hom.: 0 Cov.: 33 AF XY: 0.00000688 AC XY: 5 AN XY: 727118

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000189

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Primary dilated cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 14, 2022

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 407096). This variant has not been reported in the literature in individuals affected with TXNRD2-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.009%). This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 287 of the TXNRD2 protein (p.Leu287Arg). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 13, 2024

The p.L287R variant (also known as c.860T>G), located in coding exon 11 of the TXNRD2 gene, results from a T to G substitution at nucleotide position 860. The leucine at codon 287 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.25
CADD	Benign	22
DANN	Benign	0.84
DEOGEN2	Benign	0.042	.;.;.;.;T;T;.
Eigen	Benign	-0.37
Eigen_PC	Benign	-0.32
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.84	.;T;.;.;T;T;T
M_CAP	Benign	0.067	D
MetaRNN	Uncertain	0.52	D;D;D;D;D;D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	2.0	.;.;.;.;M;.;.
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-2.1	N;.;N;N;N;.;N
REVEL	Benign	0.25
Sift	Benign	0.22	T;.;T;T;T;.;T
Sift4G	Benign	0.59	T;T;T;T;T;T;T
Polyphen		0.17	.;.;.;.;B;.;B
Vest4		0.64
MutPred		0.38		.;.;.;.;Gain of disorder (P = 0.0127);.;Gain of disorder (P = 0.0127);
MVP		0.55
MPC		0.31
ClinPred		0.24	T
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.29

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

LitVar

Other links and lift over

dbSNP: rs989125451; hg19: chr22-19883019;