NM_020451.3:c.-42T>C

Variant names:

• chr1-25800189-T-C
• rs12121707
• NM_020451.3:c.-42T>C

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_Strong BP6 BA1

The NM_020451.3(SELENON):​c.-42T>C variant causes a upstream gene change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 1 in 273,970 control chromosomes in the GnomAD database, including 136,898 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 1.0 (72925 hom., cov: 27)
  • Exomes 𝑓: 1.0 (63973 hom.)
• Consequence: SELENON NM_020451.3 upstream_gene
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: -2.91
• Publications: 2 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, STRONG Submitted by: PanelApp Australia, G2P, Ambry Genetics
• 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 -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.91).
• BP6: Variant 1-25800189-T-C is Benign according to our data. Variant chr1-25800189-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 261269.
• BA1: GnomAd4 highest subpopulation (AMR) allele frequency at 95% confidence interval = 0.993 is higher than 0.05.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SELENON	NM_020451.3	MANE Select	c.-42T>C		upstream_gene	N/A	NP_065184.2
	SELENON	NM_206926.2		c.-42T>C		upstream_gene	N/A	NP_996809.1	Q9NZV5-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SELENON	ENST00000361547.7	TSL:1 MANE Select	c.-42T>C		upstream_gene	N/A	ENSP00000355141.2	Q9NZV5-1
	SELENON	ENST00000374315.1	TSL:5	c.-42T>C		upstream_gene	N/A	ENSP00000363434.1	Q9NZV5-2
	SELENON	ENST00000354177.9	TSL:5	c.-42T>C		upstream_gene	N/A	ENSP00000346109.5	H9KV50

Frequencies

GnomAD3 genomes AF: 1.00 AC: 145807 AN: 145844 Hom.: 72885 Cov.: 27

Gnomad AFR AF: 1.00

Gnomad AMI AF: 1.00

Gnomad AMR AF: 1.00

Gnomad ASJ AF: 1.00

Gnomad EAS AF: 1.00

Gnomad SAS AF: 1.00

Gnomad FIN AF: 1.00

Gnomad MID AF: 1.00

Gnomad NFE AF: 1.00

Gnomad OTH AF: 1.00

GnomAD4 exome AF: 1.00 AC: 127982 AN: 128046 Hom.: 63973 Cov.: 4 AF XY: 1.00 AC XY: 60866 AN XY: 60886

African (AFR) AF: 0.999 AC: 2461 AN: 2464

American (AMR) AF: 1.00 AC: 140 AN: 140

Ashkenazi Jewish (ASJ) AF: 0.999 AC: 763 AN: 764

East Asian (EAS) AF: 1.00 AC: 514 AN: 514

South Asian (SAS) AF: 1.00 AC: 2794 AN: 2794

European-Finnish (FIN) AF: 1.00 AC: 36 AN: 36

Middle Eastern (MID) AF: 1.00 AC: 252 AN: 252

European-Non Finnish (NFE) AF: 1.00 AC: 116868 AN: 116924

Other (OTH) AF: 0.999 AC: 4154 AN: 4158

GnomAD4 genome AF: 1.00 AC: 145887 AN: 145924 Hom.: 72925 Cov.: 27 AF XY: 1.00 AC XY: 70992 AN XY: 71010

African (AFR) AF: 1.00 AC: 40730 AN: 40746

American (AMR) AF: 1.00 AC: 14739 AN: 14740

Ashkenazi Jewish (ASJ) AF: 1.00 AC: 3388 AN: 3388

East Asian (EAS) AF: 1.00 AC: 5047 AN: 5048

South Asian (SAS) AF: 1.00 AC: 4784 AN: 4786

European-Finnish (FIN) AF: 1.00 AC: 8380 AN: 8384

Middle Eastern (MID) AF: 1.00 AC: 284 AN: 284

European-Non Finnish (NFE) AF: 1.00 AC: 65596 AN: 65608

Other (OTH) AF: 1.00 AC: 2035 AN: 2036

Alfa AF: 1.00 Hom.: 9257

Bravo AF: 1.00

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	1	not provided (1)
-	-	1	not specified (1)
-	1	-	SEPN1-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	6.0
DANN	Benign	0.63
PhyloP100		-2.9
PromoterAI		-0.64	Under-expression
Mutation Taster		=300/0	polymorphism (auto)

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: rs12121707; hg19: chr1-26126680;