21-31659789-G-A

Variant names:

• chr21-31659789-G-A
• rs121912448
• NM_000454.5:c.20G>A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000454.5(SOD1):​c.20G>A​(p.Cys7Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. C7W) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SOD1 NM_000454.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.53

Genes affected

SOD1 (HGNC:11179): (superoxide dismutase 1) The protein encoded by this gene binds copper and zinc ions and is one of two isozymes responsible for destroying free superoxide radicals in the body. The encoded isozyme is a soluble cytoplasmic protein, acting as a homodimer to convert naturally-occuring but harmful superoxide radicals to molecular oxygen and hydrogen peroxide. The other isozyme is a mitochondrial protein. In addition, this protein contains an antimicrobial peptide that displays antibacterial, antifungal, and anti-MRSA activity against E. coli, E. faecalis, S. aureus, S. aureus MRSA LPV+, S. agalactiae, and yeast C. krusei. Mutations in this gene have been implicated as causes of familial amyotrophic lateral sclerosis. Rare transcript variants have been reported for this gene. [provided by RefSeq, Jul 2020]

SOD1-DT (HGNC:55683): (SOD1 divergent transcript)

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a strand (size 7) in uniprot entity SODC_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000454.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr21-31659790-C-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.972

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SOD1	NM_000454.5	c.20G>A	p.Cys7Tyr	missense_variant	Exon 1 of 5	ENST00000270142.11	NP_000445.1
SOD1-DT	NR_187558.1	n.236C>T		non_coding_transcript_exon_variant	Exon 1 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SOD1	ENST00000270142.11	c.20G>A	p.Cys7Tyr	missense_variant	Exon 1 of 5	1	NM_000454.5	ENSP00000270142.7
SOD1	ENST00000389995.4	c.15+5G>A		splice_region_variant, intron_variant	Intron 1 of 4	3		ENSP00000374645.4
SOD1	ENST00000470944.1	n.81G>A		non_coding_transcript_exon_variant	Exon 1 of 5	2
SOD1	ENST00000476106.5	n.97G>A		non_coding_transcript_exon_variant	Exon 1 of 5	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Amyotrophic lateral sclerosis type 1 Uncertain:1

Dec 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 7 of the SOD1 protein (p.Cys7Tyr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with amyotrophic lateral sclerosis (PMID: 21603025). This variant is also known as C6Y. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SOD1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects SOD1 function (PMID: 23280792). This variant disrupts the p.Cys7 amino acid residue in SOD1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10624810, 23280792). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	35
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.7	H
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-8.8	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.74		Gain of disorder (P = 0.0499);
MVP		1.0
MPC		3.0
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.36		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.36		Position offset: -3

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

Publications

LitVar

Other links and lift over

dbSNP: rs121912448; hg19: chr21-33032102;