chr2-166277237-C-A

Position:

• chr2-166277237-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_001365536.1(SCN9A):​c.2620G>T​(p.Ala874Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,822 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A874P) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: SCN9A NM_001365536.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.74

Genes affected

SCN9A (HGNC:10597): (sodium voltage-gated channel alpha subunit 9) This gene encodes a voltage-gated sodium channel which plays a significant role in nociception signaling. Mutations in this gene have been associated with primary erythermalgia, channelopathy-associated insensitivity to pain, and paroxysmal extreme pain disorder. [provided by RefSeq, Aug 2009]

SCN1A-AS1 (HGNC:54069): (SCN1A and SCN9A antisense RNA 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-166277237-C-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.905

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN9A	NM_001365536.1	c.2620G>T	p.Ala874Ser	missense_variant	16/27	ENST00000642356.2	NP_001352465.1
SCN1A-AS1	NR_110260.1	n.1019C>A		non_coding_transcript_exon_variant	8/12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN9A	ENST00000642356.2	c.2620G>T	p.Ala874Ser	missense_variant	16/27		NM_001365536.1	ENSP00000495601	P1
SCN1A-AS1	ENST00000651574.1	n.1697C>A		non_coding_transcript_exon_variant	15/19

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251332 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135836

Gnomad AFR exome AF: 0.0000615

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461822 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727220

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

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Generalized epilepsy with febrile seizures plus, type 7;C2752089:Neuropathy, hereditary sensory and autonomic, type 2A Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 17, 2023

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SCN9A protein function. ClinVar contains an entry for this variant (Variation ID: 855831). This variant has not been reported in the literature in individuals affected with SCN9A-related conditions. This variant is present in population databases (rs80356477, gnomAD 0.007%). This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 863 of the SCN9A protein (p.Ala863Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	.;D;.;.;D;.;.
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.83	T;.;T;T;T;T;T
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	2.9	.;M;.;.;M;M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-2.9	D;.;.;.;.;D;.
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D;.;.;.;.;D;.
Sift4G	Benign	0.13	T;T;.;.;.;T;.
Vest4		0.70
MutPred		0.75		Loss of stability (P = 0.3174);.;Loss of stability (P = 0.3174);Loss of stability (P = 0.3174);.;.;.;
MVP		0.89
MPC		0.40
ClinPred		0.91	D
GERP RS		5.5
Varity_R		0.61
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs80356477; hg19: chr2-167133747;