20-33408539-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_003098.3(SNTA1):c.1486G>C(p.Ala496Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,158 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. A496V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

SNTA1
NM_003098.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.64

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 links:

LOC124904889 (HGNC:):

LOC124904889 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.912

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SNTA1	NM_003098.3 linkuse as main transcript	c.1486G>C	p.Ala496Pro	missense_variant	8/8	ENST00000217381.3
LOC124904889	XR_007067567.1 linkuse as main transcript	n.95-1514C>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SNTA1	ENST00000217381.3 linkuse as main transcript	c.1486G>C	p.Ala496Pro	missense_variant	8/8	1	NM_003098.3	P1	Q13424-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251382

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135882

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74314

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome 12

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jul 01, 2021

- -

Long QT syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 18, 2020

This variant has not been reported in the literature in individuals with SNTA1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with proline at codon 496 of the SNTA1 protein (p.Ala496Pro). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and proline. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 13, 2023

The p.A496P variant (also known as c.1486G>C), located in coding exon 8 of the SNTA1 gene, results from a G to C substitution at nucleotide position 1486. The alanine at codon 496 is replaced by proline, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. The evidence for this gene-disease relationship is limited; therefore, the clinical significance of this alteration is unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.37

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.93

M_CAP

Pathogenic

0.31

MetaRNN

Pathogenic

0.91

MetaSVM

Uncertain

0.55

MutationAssessor

Uncertain

2.9

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.89

PROVEAN

Uncertain

-4.3

REVEL

Pathogenic

0.85

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.92

MutPred

0.67

Loss of catalytic residue at A496 (P = 0.0308);

MVP

0.94

MPC

1.1

ClinPred

0.99

GERP RS

3.6

Varity_R

0.88

gMVP

0.86

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over