22-19941702-T-G

Position:

• chr22-19941702-T-G

Variant summary

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

The NM_006440.5(TXNRD2):​c.102A>C​(p.Ala34Ala) variant causes a splice region, synonymous 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. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as drug response (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TXNRD2 NM_006440.5 splice_region, synonymous
• Scores: Splicing: ADA: 0.8828
• Clinical Significance: drug response no assertion criteria provided O:1
• Conservation: PhyloP100: 0.845

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]

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.102A>C	p.Ala34Ala	splice_region_variant, synonymous_variant	1/18	ENST00000400521.7	NP_006431.2
TXNRD2	NM_001352300.2	c.102A>C	p.Ala34Ala	splice_region_variant, synonymous_variant	1/17		NP_001339229.1
TXNRD2	NM_001282512.3	c.102A>C	p.Ala34Ala	splice_region_variant, synonymous_variant	1/12		NP_001269441.1
TXNRD2	NR_147957.2	n.117A>C		splice_region_variant, non_coding_transcript_exon_variant	1/17

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TXNRD2	ENST00000400521.7	c.102A>C	p.Ala34Ala	splice_region_variant, synonymous_variant	1/18	1	NM_006440.5	ENSP00000383365.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: drug response

Submissions summary: Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Tramadol response Other:1

drug response, no assertion criteria provided

research

Bruce Budowle Laboratory, University of North Texas Health Science Center

Apr 28, 2018

- T:M1 = postmortem ratio or tramadol to O-desmethyltramadol; t-MP = model-based clustered metabolizer phenotype inferred from T:M1

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	21
DANN	Benign	0.84

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.88
dbscSNV1_RF	Pathogenic	0.79
SpliceAI score (max)		0.53		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.53		Position offset: -28
DS_DL_spliceai		0.25		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1601500636; hg19: chr22-19929225;