Genetic Variant TMEM74B:p.Arg157Gln (chr20-1181149-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_001304748.2(TMEM74B):c.470G>A(p.Arg157Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000409 in 1,614,162 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000041 ( 0 hom. )

Consequence

TMEM74B
NM_001304748.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.30

Variant links:

Genes affected

TMEM74B (HGNC:15893): (transmembrane protein 74B) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

TMEM74B links:

PSMF1 (HGNC:9571): (proteasome inhibitor subunit 1) The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. The 20S core is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. The 19S regulator is composed of a base, which contains 6 ATPase subunits and 2 non-ATPase subunits, and a lid, which contains up to 10 non-ATPase subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a protein that inhibits the activation of the proteasome by the 11S and 19S regulators. Alternative transcript variants have been identified for this gene. [provided by RefSeq, Jul 2008]

PSMF1 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
TMEM74B	NM_001304748.2 link	c.470G>A	p.Arg157Gln	missense_variant	Exon 3 of 3	ENST00000429036.2	NP_001291677.1	Q9NUR3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMEM74B	ENST00000429036.2 link	c.470G>A	p.Arg157Gln	missense_variant	Exon 3 of 3	3	NM_001304748.2	ENSP00000400552.2		Q9NUR3Q5QPM3

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152160

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000770

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000131

AC:

AN:

251284

Hom.:

AF XY:

0.000125

AC XY:

AN XY:

135858

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00114

Gnomad SAS exome

AF:

0.000131

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000410

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000509

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000453

Gnomad4 SAS exome

AF:

0.000151

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000216

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152278

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74466

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000772

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000386

Hom.:

Bravo

AF:

0.0000869

ExAC

AF:

0.0000824

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Nov 30, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.470G>A (p.R157Q) alteration is located in exon 2 (coding exon 2) of the TMEM74B gene. This alteration results from a G to A substitution at nucleotide position 470, causing the arginine (R) at amino acid position 157 to be replaced by a glutamine (Q). 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

Pathogenic

0.57

BayesDel_addAF

Benign

-0.075

BayesDel_noAF

Uncertain

0.070

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.25

Eigen

Pathogenic

0.70

Eigen_PC

Uncertain

0.62

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

M_CAP

Benign

0.042

MetaRNN

Uncertain

0.52

MetaSVM

Benign

-0.95

MutationAssessor

Uncertain

2.4

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-3.5

REVEL

Uncertain

0.34

Sift

Uncertain

0.0030

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.93

MVP

0.33

MPC

0.44

ClinPred

0.34

GERP RS

4.4

Varity_R

0.44

gMVP

0.72

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