20-33438897-G-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_003098.3(SNTA1):c.440C>A(p.Thr147Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000113 in 1,614,106 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. T147I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00070 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

SNTA1
NM_003098.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:3

Conservation

PhyloP100: 6.48

Publications

3 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.041083753).

BP6

Variant 20-33438897-G-T is Benign according to our data. Variant chr20-33438897-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 190930.

BS2

High AC in GnomAd4 at 106 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SNTA1	NM_003098.3 link	c.440C>A	p.Thr147Asn	missense_variant	Exon 2 of 8	ENST00000217381.3	NP_003089.1	Q13424-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SNTA1	ENST00000217381.3 link	c.440C>A	p.Thr147Asn	missense_variant	Exon 2 of 8	1	NM_003098.3	ENSP00000217381.2		Q13424-1

Frequencies

GnomAD3 genomes

AF:

0.000696

AC:

106

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00256

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:

0.000175

AC:

AN:

251490

AF XY:

0.0000883

show subpopulations

Gnomad AFR exome

AF:

0.00271

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000520

AC:

AN:

1461792

Hom.:

Cov.:

AF XY:

0.0000385

AC XY:

AN XY:

727202

show subpopulations

African (AFR)

AF:

0.00212

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111922

Other (OTH)

AF:

0.0000828

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.477

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:

0.000696

AC:

106

AN:

152314

Hom.:

Cov.:

AF XY:

0.000524

AC XY:

AN XY:

74470

show subpopulations

African (AFR)

AF:

0.00255

AC:

106

AN:

41576

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.519

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:

0.000293

Hom.:

Bravo

AF:

0.000952

ESP6500AA

AF:

0.00227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000255

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Apr 16, 2025

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported in a patient who experienced drug-induced torsades de pointes following ganciclovir and sirolimus use (PMID: 22584458), and in a patient with dilated cardiomyopathy (PMID: 32746448); however, both patients also harbored variants in other cardiac phenotype-related genes, and segregation studies were not reported; Reported in one individual from a cohort of individuals not selected for cardiomyopathy, arrhythmia, or family history of sudden cardiac death, who underwent exome sequencing (PMID: 23861362); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 23834499, 24014171, 32746448, 23861362, 22584458) -

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

Long QT syndrome 1

Uncertain:1

May 28, 2019

Mendelics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Long QT syndrome 12

Benign:1

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to rule this variant out of causing disease. Therefore, this variant is classified as benign. -

Long QT syndrome

Benign:1

Jan 31, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Sep 23, 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 v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.60

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.21

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.45

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.43

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.95

M_CAP

Benign

0.045

MetaRNN

Benign

0.041

MetaSVM

Benign

-0.44

MutationAssessor

Benign

1.6

PhyloP100

6.5

PrimateAI

Uncertain

0.67

PROVEAN

Uncertain

-4.1

REVEL

Uncertain

0.34

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0060

Polyphen

0.081

Vest4

0.67

MVP

0.63

MPC

0.84

ClinPred

0.17

GERP RS

4.0

Varity_R

0.72

gMVP

0.62

Mutation Taster

=47/53

disease causing

(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