1-25809038-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_020451.3(SELENON):c.760C>T(p.Arg254Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000607 in 1,613,744 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R254Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000063 ( 0 hom. )

Consequence

SELENON
NM_020451.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.96

Publications

0 publications found

Variant links:

Genes affected

SELENON (HGNC:15999): (selenoprotein N) This gene encodes a glycoprotein that is localized in the endoplasmic reticulum. It plays an important role in cell protection against oxidative stress, and in the regulation of redox-related calcium homeostasis. Mutations in this gene are associated with early onset muscle disorders, referred to as SEPN1-related myopathy. SEPN1-related myopathy consists of 4 autosomal recessive disorders, originally thought to be separate entities: rigid spine muscular dystrophy (RSMD1), the classical form of multiminicore disease, desmin related myopathy with Mallory-body like inclusions, and congenital fiber-type disproportion (CFTD). This protein is a selenoprotein, containing the rare amino acid selenocysteine (Sec). Sec is encoded by the UGA codon, which normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, designated the Sec insertion sequence (SECIS) element, that is necessary for the recognition of UGA as a Sec codon, rather than as a stop signal. A second stop-codon redefinition element (SRE) adjacent to the UGA codon has been identified in this gene (PMID:15791204). SRE is a phylogenetically conserved stem-loop structure that stimulates readthrough at the UGA codon, and augments the Sec insertion efficiency by SECIS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Dec 2016]

SELENON Gene-Disease associations (from GenCC):

rigid spine muscular dystrophy 1
Inheritance: AR Classification: DEFINITIVE Submitted by: Ambry Genetics, G2P
SELENON-related myopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
congenital myopathy 4A, autosomal dominant
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
congenital fiber-type disproportion myopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
desmin-related myopathy with Mallory body-like inclusions
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
rigid spine syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

SELENON links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.35656768).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SELENON	NM_020451.3 link	c.760C>T	p.Arg254Trp	missense_variant	Exon 6 of 13	ENST00000361547.7	NP_065184.2	Q9NZV5-1
SELENON	NM_206926.2 link	c.658C>T	p.Arg220Trp	missense_variant	Exon 5 of 12		NP_996809.1	Q9NZV5-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SELENON	ENST00000361547.7 link	c.760C>T	p.Arg254Trp	missense_variant	Exon 6 of 13	1	NM_020451.3	ENSP00000355141.2	Q9NZV5-1
SELENON	ENST00000374315.1 link	c.658C>T	p.Arg220Trp	missense_variant	Exon 5 of 12	5		ENSP00000363434.1	Q9NZV5-2
SELENON	ENST00000494537.2 link	n.658C>T		non_coding_transcript_exon_variant	Exon 5 of 13	3		ENSP00000508308.1	A0A804HLD6
SELENON	ENST00000354177.9 link	c.646-57C>T		intron_variant	Intron 4 of 11	5		ENSP00000346109.5	H9KV50

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152260

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000602

AC:

AN:

249200

AF XY:

0.0000739

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000115

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000630

AC:

AN:

1461366

Hom.:

Cov.:

AF XY:

0.0000605

AC XY:

AN XY:

727004

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000580

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52932

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000647

AC:

AN:

1111986

Other (OTH)

AF:

0.000132

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.481

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152378

Hom.:

Cov.:

AF XY:

0.0000268

AC XY:

AN XY:

74520

show subpopulations

African (AFR)

AF:

0.0000240

AC:

AN:

41598

American (AMR)

AF:

0.00

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.550

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000112

Hom.:

Bravo

AF:

0.0000567

ExAC

AF:

0.0000413

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000178

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Eichsfeld type congenital muscular dystrophy

Uncertain:3

Dec 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 254 of the SELENON protein (p.Arg254Trp). This variant is present in population databases (rs374195814, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SELENON-related conditions. ClinVar contains an entry for this variant (Variation ID: 572467). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SELENON protein function. 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. -

Sep 14, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 07, 2021

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

Inborn genetic diseases

Uncertain:1

Apr 15, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.760C>T (p.R254W) alteration is located in exon 6 (coding exon 6) of the SEPN1 gene. This alteration results from a C to T substitution at nucleotide position 760, causing the arginine (R) at amino acid position 254 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Jul 25, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.062

BayesDel_noAF

Benign

-0.10

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.33

.;T;.

Eigen

Uncertain

0.29

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Uncertain

0.81

LIST_S2

Uncertain

0.95

D;D;D

M_CAP

Uncertain

0.12

MetaRNN

Benign

0.36

T;T;T

MetaSVM

Uncertain

0.20

MutationAssessor

Benign

0.55

.;N;.

PhyloP100

2.0

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-4.0

D;D;D

REVEL

Uncertain

0.57

Sift

Uncertain

0.0070

D;D;D

Sift4G

Uncertain

0.0090

D;D;D

Polyphen

0.99

.;D;D

Vest4

0.58

MVP

0.97

MPC

0.25

ClinPred

0.39

GERP RS

2.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.13

Mutation Taster

=90/10

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over