20-33412656-C-T

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_ModerateBP6BP7BS1BS2

The NM_003098.3(SNTA1):​c.828G>A​(p.Lys276Lys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0148 in 1,613,964 control chromosomes in the GnomAD database, including 227 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.010 ( 15 hom., cov: 32)
Exomes 𝑓: 0.015 ( 212 hom. )

Consequence

SNTA1
NM_003098.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: 0.266

Publications

5 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -12 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.43).
BP6
Variant 20-33412656-C-T is Benign according to our data. Variant chr20-33412656-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 220958.
BP7
Synonymous conserved (PhyloP=0.266 with no splicing effect.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.0101 (1531/152312) while in subpopulation NFE AF = 0.017 (1153/68022). AF 95% confidence interval is 0.0161. There are 15 homozygotes in GnomAd4. There are 698 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 1531 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SNTA1NM_003098.3 linkc.828G>A p.Lys276Lys synonymous_variant Exon 4 of 8 ENST00000217381.3 NP_003089.1 Q13424-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SNTA1ENST00000217381.3 linkc.828G>A p.Lys276Lys synonymous_variant Exon 4 of 8 1 NM_003098.3 ENSP00000217381.2 Q13424-1
ENSG00000288878ENST00000785672.1 linkn.224+2422C>T intron_variant Intron 2 of 2

Frequencies

GnomAD3 genomes
AF:
0.0101
AC:
1532
AN:
152194
Hom.:
15
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00256
Gnomad AMI
AF:
0.00659
Gnomad AMR
AF:
0.00674
Gnomad ASJ
AF:
0.00634
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.0164
Gnomad FIN
AF:
0.00358
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.0169
Gnomad OTH
AF:
0.0110
GnomAD2 exomes
AF:
0.0105
AC:
2641
AN:
251106
AF XY:
0.0109
show subpopulations
Gnomad AFR exome
AF:
0.00289
Gnomad AMR exome
AF:
0.00471
Gnomad ASJ exome
AF:
0.00526
Gnomad EAS exome
AF:
0.000163
Gnomad FIN exome
AF:
0.00379
Gnomad NFE exome
AF:
0.0152
Gnomad OTH exome
AF:
0.00979
GnomAD4 exome
AF:
0.0152
AC:
22288
AN:
1461652
Hom.:
212
Cov.:
33
AF XY:
0.0154
AC XY:
11171
AN XY:
727134
show subpopulations
African (AFR)
AF:
0.00236
AC:
79
AN:
33480
American (AMR)
AF:
0.00526
AC:
235
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00593
AC:
155
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0159
AC:
1370
AN:
86254
European-Finnish (FIN)
AF:
0.00470
AC:
250
AN:
53228
Middle Eastern (MID)
AF:
0.00780
AC:
45
AN:
5766
European-Non Finnish (NFE)
AF:
0.0174
AC:
19325
AN:
1111978
Other (OTH)
AF:
0.0137
AC:
828
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
1381
2762
4144
5525
6906
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
706
1412
2118
2824
3530
<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:
0.0101
AC:
1531
AN:
152312
Hom.:
15
Cov.:
32
AF XY:
0.00937
AC XY:
698
AN XY:
74484
show subpopulations
African (AFR)
AF:
0.00255
AC:
106
AN:
41580
American (AMR)
AF:
0.00673
AC:
103
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00634
AC:
22
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5174
South Asian (SAS)
AF:
0.0162
AC:
78
AN:
4820
European-Finnish (FIN)
AF:
0.00358
AC:
38
AN:
10622
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.0170
AC:
1153
AN:
68022
Other (OTH)
AF:
0.0109
AC:
23
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
74
148
223
297
371
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
24
48
72
96
120
<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:
0.0154
Hom.:
51
Bravo
AF:
0.00983
Asia WGS
AF:
0.00491
AC:
17
AN:
3478
EpiCase
AF:
0.0173
EpiControl
AF:
0.0151

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Long QT syndrome 12 Benign:2
Nov 08, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Congenital long QT syndrome Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Mar 03, 2015
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Long QT syndrome Benign:1
Jan 31, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Jan 14, 2016
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as 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
BayesDel_noAF
Benign
-0.43
CADD
Benign
7.5
DANN
Benign
0.45
PhyloP100
0.27
Mutation Taster
=100/0
polymorphism

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: rs35938843; hg19: chr20-32000462; COSMIC: COSV54128319; API