chr1-25813991-C-G

Position:

• chr1-25813991-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_020451.3(SELENON):​c.1498C>G​(p.Gln500Glu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000411 in 1,461,424 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: SELENON NM_020451.3 missense, splice_region
• Scores: Splicing: ADA: 0.9059
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.36

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.27468735).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SELENON	NM_020451.3	c.1498C>G	p.Gln500Glu	missense_variant, splice_region_variant	11/13	ENST00000361547.7	NP_065184.2
SELENON	NM_206926.2	c.1396C>G	p.Gln466Glu	missense_variant, splice_region_variant	10/12		NP_996809.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SELENON	ENST00000361547.7	c.1498C>G	p.Gln500Glu	missense_variant, splice_region_variant	11/13	1	NM_020451.3	ENSP00000355141
SELENON	ENST00000374315.1	c.1396C>G	p.Gln466Glu	missense_variant, splice_region_variant	10/12	5		ENSP00000363434	P1
SELENON	ENST00000354177.9	c.1327C>G	p.Gln443Glu	missense_variant, splice_region_variant	10/12	5		ENSP00000346109
SELENON	ENST00000494537.2	c.*18C>G		splice_region_variant, 3_prime_UTR_variant, NMD_transcript_variant	11/13	3		ENSP00000508308

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000802 AC: 2 AN: 249458 Hom.: 0 AF XY: 0.00000739 AC XY: 1 AN XY: 135372

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: 0.0000177

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461424 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727010

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000826 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Eichsfeld type congenital muscular dystrophy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	May 24, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 16, 2022	This variant is present in population databases (rs763724398, gnomAD 0.002%). 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 578217). This variant has not been reported in the literature in individuals affected with SELENON-related conditions. This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 500 of the SELENON protein (p.Gln500Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.080	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.23	.;T;.
Eigen	Uncertain	0.22
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.81	T;T;T
M_CAP	Benign	0.051	D
MetaRNN	Benign	0.27	T;T;T
MetaSVM	Uncertain	0.26	D
MutationAssessor	Benign	1.9	.;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-1.4	N;N;N
REVEL	Uncertain	0.47
Sift	Uncertain	0.022	D;D;D
Sift4G	Uncertain	0.026	D;D;D
Polyphen		0.43, 0.42	.;B;B
Vest4		0.45
MutPred		0.20		.;Gain of disorder (P = 0.1113);.;
MVP		0.91
MPC		0.33
ClinPred		0.47	T
GERP RS		5.0
Varity_R		0.31

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.91
dbscSNV1_RF	Benign	0.61
SpliceAI score (max)		0.13		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

Other links and lift over

dbSNP: rs763724398; hg19: chr1-26140482;