chr9-128580928-G-C

Position:

• chr9-128580928-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM2 PM5 PP2 BP4_Moderate

The ENST00000372739.7(SPTAN1):​c.1330G>C​(p.Val444Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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. V444I) has been classified as Benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: SPTAN1 ENST00000372739.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0890

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-128580928-G-A is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SPTAN1. . Gene score misZ 5.523 (greater than the threshold 3.09). Trascript score misZ 7.9287 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 5, developmental and epileptic encephalopathy, West syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.1187475).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPTAN1	NM_001130438.3	c.1330G>C	p.Val444Leu	missense_variant	11/57	ENST00000372739.7	NP_001123910.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPTAN1	ENST00000372739.7	c.1330G>C	p.Val444Leu	missense_variant	11/57	1	NM_001130438.3	ENSP00000361824	P3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 18, 2023

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 444 of the SPTAN1 protein (p.Val444Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of developmental and epileptic encephalopathy (Invitae). ClinVar contains an entry for this variant (Variation ID: 1442358). 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) has been performed at Invitae 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.094
BayesDel_addAF	Benign	-0.35	T
BayesDel_noAF	Benign	-0.74
CADD	Benign	0.31
DANN	Benign	0.82
DEOGEN2	Benign	0.12	T;.;.;.;.
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.85	D;D;D;D;D
M_CAP	Benign	0.0030	T
MetaRNN	Benign	0.12	T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.55	N;.;N;N;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.61	N;.;N;N;.
REVEL	Benign	0.051
Sift	Benign	0.38	T;.;T;T;.
Sift4G	Benign	0.39	T;T;T;T;T
Polyphen		0.0010	B;.;B;B;.
Vest4		0.30
MutPred		0.52		Gain of disorder (P = 0.0832);Gain of disorder (P = 0.0832);Gain of disorder (P = 0.0832);Gain of disorder (P = 0.0832);Gain of disorder (P = 0.0832);
MVP		0.23
MPC		0.82
ClinPred		0.12	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.032
gMVP		0.060

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-131343207;