1-25815690-G-T

Variant names:

• chr1-25815690-G-T
• rs74060854
• NM_020451.3:c.1745G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020451.3(SELENON):​c.1745G>T​(p.Arg582Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R582W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: SELENON NM_020451.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.12
• Publications: 0 publications found

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

ENSG00000255054 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20693615).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020451.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SELENON	NM_020451.3	MANE Select	c.1745G>T	p.Arg582Leu	missense	Exon 13 of 13	NP_065184.2
	SELENON	NM_206926.2		c.1643G>T	p.Arg548Leu	missense	Exon 12 of 12	NP_996809.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SELENON	ENST00000361547.7	TSL:1 MANE Select	c.1745G>T	p.Arg582Leu	missense	Exon 13 of 13	ENSP00000355141.2
	ENSG00000255054	ENST00000527604.1	TSL:5	n.123+1512G>T		intron	N/A	ENSP00000457066.1
	SELENON	ENST00000374315.1	TSL:5	c.1643G>T	p.Arg548Leu	missense	Exon 12 of 12	ENSP00000363434.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461782 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727200

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53336

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111998

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0188335), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.0010	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	14
DANN	Uncertain	0.99
DEOGEN2	Benign	0.13	T
Eigen	Benign	-0.48
Eigen_PC	Benign	-0.45
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.063	D
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-0.58	T
MutationAssessor	Benign	1.1	L
PhyloP100		2.1
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.92	N
REVEL	Benign	0.20
Sift	Benign	0.044	D
Sift4G	Benign	0.19	T
Polyphen		0.47	P
Vest4		0.35
MutPred		0.29		Loss of solvent accessibility (P = 0.0098)
MVP		0.82
MPC		0.36
ClinPred		0.23	T
GERP RS		0.70
Varity_R		0.062
Mutation Taster		=91/9	polymorphism

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

Other links and lift over

dbSNP: rs74060854; hg19: chr1-26142181;