20-33412344-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_003098.3(SNTA1):c.992G>A(p.Arg331His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000106 in 1,611,318 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R331C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

SNTA1
NM_003098.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 2.03

Publications

0 publications found

Variant links:

Genes affected

SNTA1 (HGNC:11167): (syntrophin alpha 1) Syntrophins are cytoplasmic peripheral membrane scaffold proteins that are components of the dystrophin-associated protein complex. This gene is a member of the syntrophin gene family and encodes the most common syntrophin isoform found in cardiac tissues. The N-terminal PDZ domain of this syntrophin protein interacts with the C-terminus of the pore-forming alpha subunit (SCN5A) of the cardiac sodium channel Nav1.5. This protein also associates cardiac sodium channels with the nitric oxide synthase-PMCA4b (plasma membrane Ca-ATPase subtype 4b) complex in cardiomyocytes. This gene is a susceptibility locus for Long-QT syndrome (LQT) - an inherited disorder associated with sudden cardiac death from arrhythmia - and sudden infant death syndrome (SIDS). This protein also associates with dystrophin and dystrophin-related proteins at the neuromuscular junction and alters intracellular calcium ion levels in muscle tissue. [provided by RefSeq, Jan 2013]

SNTA1 Gene-Disease associations (from GenCC):

long QT syndrome 12
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
long QT syndrome
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

SNTA1 links:

LOC124904889 (HGNC:):

LOC124904889 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.839

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SNTA1	NM_003098.3 link	c.992G>A	p.Arg331His	missense_variant	Exon 5 of 8	ENST00000217381.3	NP_003089.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SNTA1	ENST00000217381.3 link	c.992G>A	p.Arg331His	missense_variant	Exon 5 of 8	1	NM_003098.3	ENSP00000217381.2
ENSG00000288878	ENST00000785672.1 link	n.224+2110C>T		intron_variant	Intron 2 of 2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152014

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

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:

0.0000247

AC:

AN:

242540

AF XY:

0.0000228

show subpopulations

Gnomad AFR exome

AF:

0.0000653

Gnomad AMR exome

AF:

0.0000295

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000366

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000822

AC:

AN:

1459304

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

725736

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33454

American (AMR)

AF:

0.00

AC:

AN:

44324

Ashkenazi Jewish (ASJ)

AF:

0.0000384

AC:

AN:

26028

East Asian (EAS)

AF:

0.00

AC:

AN:

39648

South Asian (SAS)

AF:

0.0000350

AC:

AN:

85668

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53054

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5578

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111306

Other (OTH)

AF:

0.00

AC:

AN:

60244

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000329

AC:

AN:

152014

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74232

show subpopulations

African (AFR)

AF:

0.000121

AC:

AN:

41388

American (AMR)

AF:

0.00

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4800

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10596

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68006

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000132

Hom.:

Bravo

AF:

0.0000491

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome 12

Uncertain:2

Oct 21, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified

Uncertain:1

Sep 04, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

Jun 18, 2014

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The R331H variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. The R331H variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Although the R331H variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties, this substitution occurs at a position that is conserved in mammals. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, no missense mutations in nearby residues have been reported in association with LQTS or arrhythmia, suggesting this region of the protein may be tolerant of change. 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 ARRHYTHMIA panel(s). -

Long QT syndrome

Uncertain:1

Jun 15, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with SNTA1-related conditions. 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. 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) performed at Invitae indicates that this missense variant is not expected to disrupt SNTA1 protein function. ClinVar contains an entry for this variant (Variation ID: 190917). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 331 of the SNTA1 protein (p.Arg331His). -

Cardiovascular phenotype

Uncertain:1

Jun 27, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R331H variant (also known as c.992G>A), located in coding exon 5 of the SNTA1 gene, results from a G to A substitution at nucleotide position 992. The arginine at codon 331 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.24

CADD

Uncertain

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.89

Eigen

Uncertain

0.36

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.76

M_CAP

Uncertain

0.13

MetaRNN

Pathogenic

0.84

MetaSVM

Uncertain

-0.17

MutationAssessor

Uncertain

2.2

PhyloP100

2.0

PrimateAI

Uncertain

0.52

PROVEAN

Uncertain

-3.3

REVEL

Uncertain

0.39

Sift

Benign

0.052

Sift4G

Benign

0.10

Polyphen

1.0

Vest4

0.58

MVP

0.81

MPC

0.97

ClinPred

0.77

GERP RS

5.0

Varity_R

0.17

gMVP

0.51

Mutation Taster

=73/27

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over