NM_020451.3:c.404-23dupT

Variant names:

• chr1-25805118-C-CT
• rs560595923
• NM_020451.3:c.404-23dupT

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP6_Moderate BS1 BS2

The NM_020451.3(SELENON):​c.404-23dupT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000824 in 1,612,362 control chromosomes in the GnomAD database, including 10 homozygotes. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.00049 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00086 (9 hom.)
• Consequence: SELENON NM_020451.3 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.111
• 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

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP6: Variant 1-25805118-C-CT is Benign according to our data. Variant chr1-25805118-C-CT is described in ClinVar as Likely_benign. ClinVar VariationId is 261282.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000486 (74/152292) while in subpopulation SAS AF = 0.0147 (71/4826). AF 95% confidence interval is 0.012. There are 1 homozygotes in GnomAd4. There are 48 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAdExome4 at 9 AR,AD gene

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.404-23dupT		intron	N/A	NP_065184.2
	SELENON	NM_206926.2		c.302-23dupT		intron	N/A	NP_996809.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SELENON	ENST00000361547.7	TSL:1 MANE Select	c.404-24_404-23insT		intron	N/A	ENSP00000355141.2
	SELENON	ENST00000374315.1	TSL:5	c.302-24_302-23insT		intron	N/A	ENSP00000363434.1
	SELENON	ENST00000354177.9	TSL:5	c.302-24_302-23insT		intron	N/A	ENSP00000346109.5

Frequencies

GnomAD3 genomes AF: 0.000480 AC: 73 AN: 152174 Hom.: 1 Cov.: 32

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: 0.0145

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00180 AC: 448 AN: 248524 AF XY: 0.00248

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000111

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000661

GnomAD4 exome AF: 0.000860 AC: 1255 AN: 1460070 Hom.: 9 Cov.: 30 AF XY: 0.00129 AC XY: 938 AN XY: 726284

African (AFR) AF: 0.0000299 AC: 1 AN: 33444

American (AMR) AF: 0.0000447 AC: 2 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.0000504 AC: 2 AN: 39696

South Asian (SAS) AF: 0.0140 AC: 1206 AN: 86200

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52768

Middle Eastern (MID) AF: 0.000204 AC: 1 AN: 4904

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111920

Other (OTH) AF: 0.000680 AC: 41 AN: 60284

GnomAD4 genome AF: 0.000486 AC: 74 AN: 152292 Hom.: 1 Cov.: 32 AF XY: 0.000645 AC XY: 48 AN XY: 74468

African (AFR) AF: 0.0000241 AC: 1 AN: 41558

American (AMR) AF: 0.00 AC: 0 AN: 15308

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5170

South Asian (SAS) AF: 0.0147 AC: 71 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00680 AC: 2 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68020

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000642

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.11
Mutation Taster		=100/0	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: rs560595923; hg19: chr1-26131609;