Genetic Variant TMX3:p.Lys267Met (chr18-68684238-T-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_019022.5(TMX3):c.800A>T(p.Lys267Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,611,494 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000033 ( 1 hom. )

Consequence

TMX3
NM_019022.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.52

Variant links:

Genes affected

TMX3 (HGNC:24718): (thioredoxin related transmembrane protein 3) This gene encodes a member of the disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins that catalyze protein folding and thiol-disulfide interchange reactions. The canonical protein encoded by this gene has an N-terminal ER-signal sequence, a catalytically active thioredoxin domain, one transmembrane domain and a C-terminal ER-retention sequence. This gene is expressed in many tissues but has its highest expression in heart and skeletal muscle. It is expressed in the retinal neuroepithelium and lens epithelium in the developing murine eye and haploinsufficiency of this gene in humans and zebrafish is associated with microphthalmia. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Apr 2017]

TMX3 links:

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ACMG classification

Classification made for transcript

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 rank	MANE	Protein	UniProt
TMX3	NM_019022.5 link	c.800A>T	p.Lys267Met	missense_variant	Exon 12 of 16	ENST00000299608.7	NP_061895.3	Q96JJ7-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TMX3	ENST00000299608.7 link	c.800A>T	p.Lys267Met	missense_variant	Exon 12 of 16	1	NM_019022.5	ENSP00000299608.2	Q96JJ7-1
TMX3	ENST00000564631.5 link	n.*484A>T		non_coding_transcript_exon_variant	Exon 11 of 15	1		ENSP00000456587.1	H3BVI1
TMX3	ENST00000564631.5 link	n.*484A>T		3_prime_UTR_variant	Exon 11 of 15	1		ENSP00000456587.1	H3BVI1
TMX3	ENST00000578765.1 link	n.375A>T		non_coding_transcript_exon_variant	Exon 3 of 4	4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250254

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135278

show subpopulations

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000265

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000329

AC:

AN:

1459314

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

726070

show subpopulations

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:

0.0000432

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 05, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.800A>T (p.K267M) alteration is located in exon 12 (coding exon 12) of the TMX3 gene. This alteration results from a A to T substitution at nucleotide position 800, causing the lysine (K) at amino acid position 267 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.53

BayesDel_addAF

Uncertain

0.029

BayesDel_noAF

Benign

-0.13

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.031

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

M_CAP

Benign

0.040

MetaRNN

Uncertain

0.72

MetaSVM

Benign

-0.68

MutationAssessor

Uncertain

2.6

PrimateAI

Uncertain

0.49

PROVEAN

Uncertain

-3.2

REVEL

Benign

0.26

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.019

Polyphen

1.0

Vest4

0.67

MVP

0.43

MPC

1.1

ClinPred

0.96

GERP RS

5.4

Varity_R

0.55

gMVP

0.82

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over