chr9-128617987-G-A

Position:

• chr9-128617987-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP2 PP3

The NM_001130438.3(SPTAN1):​c.5479G>A​(p.Gly1827Ser) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000197 in 152,268 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.000020 (0 hom., cov: 31)
• Consequence: SPTAN1 NM_001130438.3 missense, splice_region
• Scores: Splicing: ADA: 0.9991
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.38

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 2 ACMG points.

• 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.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPTAN1	NM_001130438.3	c.5479G>A	p.Gly1827Ser	missense_variant, splice_region_variant	43/57	ENST00000372739.7	NP_001123910.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPTAN1	ENST00000372739.7	c.5479G>A	p.Gly1827Ser	missense_variant, splice_region_variant	43/57	1	NM_001130438.3	ENSP00000361824	P3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152150 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000579

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

GnomAD4 exome Cov.: 34

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152268 Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1 AN XY: 74462

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000580

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

Asia WGS AF: 0.000289 AC: 1 AN: 3478

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

Jun 09, 2023

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 530504). This variant has not been reported in the literature in individuals affected with SPTAN1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1827 of the SPTAN1 protein (p.Gly1827Ser). 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	0.075
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Benign	0.081	T;.;.;.;.
Eigen	Benign	0.062
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Benign	0.0061	T
MetaRNN	Benign	0.15	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.41	N;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.050	N;.;N;.;.
REVEL	Benign	0.085
Sift	Benign	0.50	T;.;T;.;.
Sift4G	Benign	0.47	T;T;T;T;T
Polyphen		0.0010	B;.;B;B;.
Vest4		0.27
MutPred		0.28		Loss of catalytic residue at P1818 (P = 0.0711);.;.;.;.;
MVP		0.24
MPC		0.77
ClinPred		0.85	D
GERP RS		6.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.10
gMVP		0.14

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.87
SpliceAI score (max)		0.090		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: rs1287628912; hg19: chr9-131380266;