22-19918931-T-G

Variant names:

• chr22-19918931-T-G
• rs200076623
• NM_006440.5:c.303A>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_006440.5(TXNRD2):​c.303A>C​(p.Ala101Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A101A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TXNRD2 NM_006440.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -3.30
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial glucocorticoid deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• glucocorticoid deficiency 5

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP7: Synonymous conserved (PhyloP=-3.3 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006440.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TXNRD2	NM_006440.5	MANE Select	c.303A>C	p.Ala101Ala	synonymous	Exon 4 of 18	NP_006431.2
	TXNRD2	NM_001352300.2		c.300A>C	p.Ala100Ala	synonymous	Exon 4 of 17	NP_001339229.1
	TXNRD2	NM_001352301.2		c.213A>C	p.Ala71Ala	synonymous	Exon 4 of 18	NP_001339230.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TXNRD2	ENST00000400521.7	TSL:1 MANE Select	c.303A>C	p.Ala101Ala	synonymous	Exon 4 of 18	ENSP00000383365.1
	TXNRD2	ENST00000400519.6	TSL:1	c.300A>C	p.Ala100Ala	synonymous	Exon 4 of 17	ENSP00000383363.1
	TXNRD2	ENST00000400518.5	TSL:1	c.213A>C	p.Ala71Ala	synonymous	Exon 4 of 18	ENSP00000383362.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD2 exomes AF: 0.00000402 AC: 1 AN: 248598 AF XY: 0.00000740

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460948 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726854

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44696

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52566

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111978

Other (OTH) AF: 0.00 AC: 0 AN: 60376

GnomAD4 genome Cov.: 29

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	0.44
DANN	Benign	0.51
PhyloP100		-3.3

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

Other links and lift over

dbSNP: rs200076623; hg19: chr22-19906454;