9-128584309-G-T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BS1_SupportingBS2

The NM_001130438.3(SPTAN1):​c.2221G>T​(p.Ala741Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,614,114 control chromosomes in the GnomAD database, including 1 homozygotes. 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. A741D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000059 ( 1 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

SPTAN1
NM_001130438.3 missense

Scores

4
9
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 9.53

Publications

1 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.0000591 (9/152236) while in subpopulation AMR AF = 0.000589 (9/15290). AF 95% confidence interval is 0.000307. There are 1 homozygotes in GnomAd4. There are 3 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 9 AD gene.

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
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPTAN1
NM_001130438.3
MANE Select
c.2221G>Tp.Ala741Ser
missense
Exon 17 of 57NP_001123910.1
SPTAN1
NM_001375318.1
c.2257G>Tp.Ala753Ser
missense
Exon 18 of 59NP_001362247.1
SPTAN1
NM_001375310.1
c.2221G>Tp.Ala741Ser
missense
Exon 17 of 58NP_001362239.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPTAN1
ENST00000372739.7
TSL:1 MANE Select
c.2221G>Tp.Ala741Ser
missense
Exon 17 of 57ENSP00000361824.4
SPTAN1
ENST00000372731.8
TSL:1
c.2221G>Tp.Ala741Ser
missense
Exon 17 of 56ENSP00000361816.4
SPTAN1
ENST00000358161.9
TSL:1
c.2221G>Tp.Ala741Ser
missense
Exon 17 of 55ENSP00000350882.6

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152118
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000589
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:
0.0000159
AC:
4
AN:
251178
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.0000616
Gnomad AMR exome
AF:
0.0000578
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:
0.000163
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461878
Hom.:
0
Cov.:
37
AF XY:
0.00000275
AC XY:
2
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
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:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000591
AC:
9
AN:
152236
Hom.:
1
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74440
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41522
American (AMR)
AF:
0.000589
AC:
9
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68012
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.446
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.000128
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1
Oct 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 741 of the SPTAN1 protein (p.Ala741Ser). This variant is present in population databases (rs200241514, gnomAD 0.007%). 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: 207325). 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.

not provided Uncertain:1
Jan 26, 2017
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

p.Ala741Ser (GCC>TCC): c.2221 G>T in exon 17 of the SPTAN1 gene (NM_001130438.2) The A741S variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, but the 1000 Genomes Project reports A741S was observed in 1/110 (0.9%) alleles from individuals of Puerto Rican background, indicating it may be a rare (benign) variant in this population. The A741S variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, previously reported pathogenic mutations in SPTAN1 include in-frame deletions or duplications located within the last four spectrin repeats of the protein, which are essential for dimerization (Saitsu et al., 2010), and the A741 residue is outside this region. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic mutation or a rare benign variant. The variant is found in EPILEPSY panel(s).

Developmental and epileptic encephalopathy, 5 Uncertain:1
Jul 15, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Uncertain
0.072
D
BayesDel_noAF
Benign
-0.13
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.47
T
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.90
D
M_CAP
Benign
0.074
D
MetaRNN
Uncertain
0.56
D
MetaSVM
Benign
-0.67
T
MutationAssessor
Benign
1.6
L
PhyloP100
9.5
PrimateAI
Pathogenic
0.84
D
PROVEAN
Uncertain
-2.7
D
REVEL
Uncertain
0.34
Sift
Uncertain
0.0050
D
Sift4G
Uncertain
0.0030
D
Polyphen
1.0
D
Vest4
0.81
MVP
0.64
MPC
1.4
ClinPred
0.80
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.52
gMVP
0.49
Mutation Taster
=39/61
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

Publications

Other links and lift over

dbSNP: rs200241514; hg19: chr9-131346588; API