NM_001130438.3:c.2548A>G

Variant names:

• chr9-128584831-A-G
• rs371776794
• NM_001130438.3:c.2548A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP3 BP6

The NM_001130438.3(SPTAN1):​c.2548A>G​(p.Met850Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,162 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M850L) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SPTAN1 NM_001130438.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 8.88
• Publications: 0 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.757
• BP6: Variant 9-128584831-A-G is Benign according to our data. Variant chr9-128584831-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1472457.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001130438.3. 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
	SPTAN1	NM_001130438.3	MANE Select	c.2548A>G	p.Met850Val	missense	Exon 18 of 57	NP_001123910.1
	SPTAN1	NM_001375318.1		c.2584A>G	p.Met862Val	missense	Exon 19 of 59	NP_001362247.1
	SPTAN1	NM_001375310.1		c.2548A>G	p.Met850Val	missense	Exon 18 of 58	NP_001362239.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPTAN1	ENST00000372739.7	TSL:1 MANE Select	c.2548A>G	p.Met850Val	missense	Exon 18 of 57	ENSP00000361824.4
	SPTAN1	ENST00000372731.8	TSL:1	c.2548A>G	p.Met850Val	missense	Exon 18 of 56	ENSP00000361816.4
	SPTAN1	ENST00000358161.9	TSL:1	c.2548A>G	p.Met850Val	missense	Exon 18 of 55	ENSP00000350882.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152162 Hom.: 0 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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251460 AF XY: 0.00000736

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 37

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152162 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74328

African (AFR) AF: 0.0000241 AC: 1 AN: 41442

American (AMR) AF: 0.00 AC: 0 AN: 15262

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1

Oct 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 850 of the SPTAN1 protein (p.Met850Val). This variant is present in population databases (rs371776794, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of SPTAN1-related conditions (internal data). ClinVar contains an entry for this variant (Variation ID: 1472457). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SPTAN1 protein function. 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.

Inborn genetic diseases Benign:1

Jun 25, 2019

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.46	T
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.76	D
MetaSVM	Benign	-0.58	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		8.9
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-3.2	D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0060	D
Polyphen		0.27	B
Vest4		0.76
MVP		0.79
MPC		1.6
ClinPred		0.95	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.61
gMVP		0.81
Mutation Taster		=45/55	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: rs371776794; hg19: chr9-131347110;