rs1193718145

Variant names:

• chr9-128626481-C-T
• rs1193718145
• NM_001130438.3:c.6370C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PP3 PP5_Moderate BS2

The NM_001130438.3(SPTAN1):​c.6370C>T​(p.Arg2124Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000821 in 1,461,862 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R2124H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: SPTAN1 NM_001130438.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.68
• Publications: 2 publications found

Genes affected

SPTAN1 (HGNC:11273): (spectrin alpha, non-erythrocytic 1) Spectrins are a family of filamentous cytoskeletal proteins that function as essential scaffold proteins that stabilize the plasma membrane and organize intracellular organelles. Spectrins are composed of alpha and beta dimers that associate to form tetramers linked in a head-to-head arrangement. This gene encodes an alpha spectrin that is specifically expressed in nonerythrocytic cells. The encoded protein has been implicated in other cellular functions including DNA repair and cell cycle regulation. Mutations in this gene are the cause of early infantile epileptic encephalopathy-5. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Sep 2010]

SPTAN1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.771
• PP5: Variant 9-128626481-C-T is Pathogenic according to our data. Variant chr9-128626481-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 530418.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPTAN1	NM_001130438.3	c.6370C>T	p.Arg2124Cys	missense_variant	Exon 49 of 57	ENST00000372739.7	NP_001123910.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPTAN1	ENST00000372739.7	c.6370C>T	p.Arg2124Cys	missense_variant	Exon 49 of 57	1	NM_001130438.3	ENSP00000361824.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00 AC: 0 AN: 251436 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461862 Hom.: 0 Cov.: 37 AF XY: 0.00000963 AC XY: 7 AN XY: 727236

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

American (AMR) AF: 0.00 AC: 0 AN: 44722

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000108 AC: 12 AN: 1112010

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

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy Pathogenic:1

Sep 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 530418). This missense change has been observed in individual(s) with clinical features of developmental and epileptic encephalopathy (PMID: 31452935; Invitae). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 2124 of the SPTAN1 protein (p.Arg2124Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.44	T;.;.;.;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.77	D;D;D;D;D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Pathogenic	2.9	M;.;.;.;.
PhyloP100		3.7
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-6.2	D;.;D;.;.
REVEL	Uncertain	0.53
Sift	Uncertain	0.0010	D;.;D;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		1.0	D;.;D;D;.
Vest4		0.77
MutPred		0.54		Loss of phosphorylation at S2122 (P = 0.0541);.;.;.;.;
MVP		0.82
MPC		2.1
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.57
gMVP		0.66
Mutation Taster		=30/70	disease causing

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: rs1193718145; hg19: chr9-131388760;